# Environment Inheritence

**URL:** <https://discourse.chef.io/t/environment-inheritence/6676>\
**Category:** Chef Infra (archive)\
**Created:** [June 18, 2015, 5:48pm UTC](https://discourse.chef.io/t/environment-inheritence/6676 "2015-06-18T17:48:02Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![Douglas\_Garstang](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@Douglas\_Garstang](https://discourse.chef.io/u/Douglas_Garstang)\
**Post date:** [June 18, 2015, 5:48pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/1 "2015-06-18T17:48:02Z")

</div>

All,

I’m making pretty heavy use of environments. There’s quite a fair bit of  
duplication and I’d like to implement a ‘base’ environment, with common  
attributes that apply to all environments. How would I do this?

What happens if the same attribute is defined in multiple environments? Are  
they merged together or does the ‘inherited’ one override the ‘base’ one?

Thanks,  
Doug

---

<div class="post-metadata">

**Author:** ![Nathen\_Harvey3](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/nathen_harvey3/32/16_2.png) [@Nathen\_Harvey3](https://discourse.chef.io/u/Nathen_Harvey3)\
**Post date:** [June 18, 2015, 5:52pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/2 "2015-06-18T17:52:02Z")

</div>

A node can only have one environment. I'm not sure you'd be able to create  
a 'base' environment or, even if you could, if it would be recommended.

I'd recommend setting good defaults in your cookbooks and then overriding  
those using attributes in environments.

On Thu, Jun 18, 2015 at 1:48 PM, Douglas Garstang [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
wrote:

> All,
> 
> I'm making pretty heavy use of environments. There's quite a fair bit of  
> duplication and I'd like to implement a 'base' environment, with common  
> attributes that apply to all environments. How would I do this?
> 
> What happens if the same attribute is defined in multiple environments?  
> Are they merged together or does the 'inherited' one override the 'base'  
> one?
> 
> Thanks,  
> Doug

---

<div class="post-metadata">

**Author:** ![Douglas\_Garstang](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@Douglas\_Garstang](https://discourse.chef.io/u/Douglas_Garstang)\
**Post date:** [June 18, 2015, 5:57pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/3 "2015-06-18T17:57:47Z")

</div>

Nathan,

I'm making heavy use of community cookbooks. As such there isn't a cookbook  
I can place attributes in, in most cases. Unless, I start wrapping just to  
set attributes in a cookbook, which doesn't make sense to me.

Douglas.

On Thu, Jun 18, 2015 at 10:52 AM, Nathen Harvey [nharvey@chef.io](mailto:nharvey@chef.io) wrote:

> A node can only have one environment. I'm not sure you'd be able to  
> create a 'base' environment or, even if you could, if it would be  
> recommended.
> 
> I'd recommend setting good defaults in your cookbooks and then overriding  
> those using attributes in environments.
> 
> On Thu, Jun 18, 2015 at 1:48 PM, Douglas Garstang \<[doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)
> 
> > wrote:
> 
> > All,
> > 
> > I'm making pretty heavy use of environments. There's quite a fair bit of  
> > duplication and I'd like to implement a 'base' environment, with common  
> > attributes that apply to all environments. How would I do this?
> > 
> > What happens if the same attribute is defined in multiple environments?  
> > Are they merged together or does the 'inherited' one override the 'base'  
> > one?
> > 
> > Thanks,  
> > Doug

--  
Regards,

Douglas Garstang  
[http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
Cell: +1-805-340-5627

---

<div class="post-metadata">

**Author:** ![Drew\_Blessing1](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/drew_blessing1/32/51_2.png) [@Drew\_Blessing1](https://discourse.chef.io/u/Drew_Blessing1)\
**Post date:** [June 18, 2015, 6:04pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/4 "2015-06-18T18:04:33Z")

</div>

You can create a base role with attributes that apply to all environments.  
Then set specific attributes in environments. Note that roles have a higher  
precedence than environments, though.

When you say you're heavily using environments are you overloading the  
definition of an environment to include locations/datacenter or something?  
If so, you might be abusing environments 🙂 Roles/role cookbooks or  
something else might be more appropriate. Something to think about.  
On Thu, Jun 18, 2015 at 12:48 PM Douglas Garstang [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
wrote:

> All,
> 
> I'm making pretty heavy use of environments. There's quite a fair bit of  
> duplication and I'd like to implement a 'base' environment, with common  
> attributes that apply to all environments. How would I do this?
> 
> What happens if the same attribute is defined in multiple environments?  
> Are they merged together or does the 'inherited' one override the 'base'  
> one?
> 
> Thanks,  
> Doug

---

<div class="post-metadata">

**Author:** ![Brian\_O\_Connell](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Brian\_O\_Connell](https://discourse.chef.io/u/Brian_O_Connell)\
**Post date:** [June 18, 2015, 6:21pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/5 "2015-06-18T18:21:58Z")

</div>

Doug - We ran into the same thing and ended up rolling our own solution.. We keep our reusable parts of the environment in separate json files. We then have one yaml file that describes the merge order and any attribute overrides necessary for that final environment. The items in the override attributes take precedence over anything in the merged\_from files. So for example, here is a snippet with placeholders '\<\>' in place of actual environments from our environments.yml: environments:- name: \<security\_zone\>_\<application\_zone\>_\<datacenter\>

description: \<Description here\>

override\_attributes:

```
name_resolution:

  nameservers: ['&lt;value1'&gt;, '&lt;value 2&gt;']

  extra_search_domains: ['&lt;value1&gt;','&lt;value2&gt;']

```

merged\_from:

```
 - &lt;security_zone&gt;.json

 - &lt;application_zone&gt;.json

 - &lt;datacenter&gt;.json Application zone is normal things like pre, prod, test, etc. We then have about 20 lines of ruby that do a deep merge on the json files and they are merged in the order you specify. When it is done, it spits out our 30+ different environments which we can upload into our chef server. This works well for us because we have a lot of environment combinations that share enough common attributes, but need to be different for many reasons. 

```

- 

Brian O'Connell, STSM

Master Inventor, Cloud Services

IBM - Continuous Availability Services

> ----- Original message -----
> 
> From: Douglas Garstang \<doug.garstang@gmail.com\>
> 
> To: [chef@lists.opscode.com](mailto:chef@lists.opscode.com)
> 
> Cc:
> 
> Subject: [chef] Environment Inheritence
> 
> Date: Thu, Jun 18, 2015 1:48 PM
> 
> All,I'm making pretty heavy use of environments. There's quite a fair bit of duplication and I'd like to implement a 'base' environment, with common attributes that apply to all environments. How would I do this?
> 
> What happens if the same attribute is defined in multiple environments? Are they merged together or does the 'inherited' one override the 'base' one?
> 
> Thanks,
> 
> Doug

---

<div class="post-metadata">

**Author:** ![Douglas\_Garstang](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@Douglas\_Garstang](https://discourse.chef.io/u/Douglas_Garstang)\
**Post date:** [June 18, 2015, 6:24pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/6 "2015-06-18T18:24:56Z")

</div>

Drew,

In our case, an environment is pinned to a physical location. For example,  
our 'dev' and 'qa' environment is located wholly with Amazon AWS us-east-1.

If I use the chef-client cookbook as an example, it needs to have the  
address of the chef server set. If I set that in a role, the 'chef-client'  
role, then the address of the chef server is not consistent across all  
locations within that role. Adding a role of 'chef-client' to a node would  
not adequately capture the fact that in the dev environment it needs to be  
one thing, while in the prod environment it needs to be something else.

If a role has a higher precedence than an environment, it sounds like  
creating a base role with attributes, and then setting attributes in  
environments would not work at all.

Doug.

On Thu, Jun 18, 2015 at 11:04 AM, Drew Blessing [drew@blessing.io](mailto:drew@blessing.io) wrote:

> You can create a base role with attributes that apply to all environments.  
> Then set specific attributes in environments. Note that roles have a higher  
> precedence than environments, though.
> 
> When you say you're heavily using environments are you overloading the  
> definition of an environment to include locations/datacenter or something?  
> If so, you might be abusing environments 🙂 Roles/role cookbooks or  
> something else might be more appropriate. Something to think about.  
> On Thu, Jun 18, 2015 at 12:48 PM Douglas Garstang [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
> wrote:
> 
> > All,
> > 
> > I'm making pretty heavy use of environments. There's quite a fair bit of  
> > duplication and I'd like to implement a 'base' environment, with common  
> > attributes that apply to all environments. How would I do this?
> > 
> > What happens if the same attribute is defined in multiple environments?  
> > Are they merged together or does the 'inherited' one override the 'base'  
> > one?
> > 
> > Thanks,  
> > Doug

--  
Regards,

Douglas Garstang  
[http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
Cell: +1-805-340-5627

---

<div class="post-metadata">

**Author:** ![Yoshi\_Spendiff](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/yoshi_spendiff/32/13_2.png) [@Yoshi\_Spendiff](https://discourse.chef.io/u/Yoshi_Spendiff)\
**Post date:** [June 18, 2015, 7:52pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/7 "2015-06-18T19:52:53Z")

</div>

Roles and Environments have two attribute levels available, default and  
override, so you can do overrides either way.

> **[About Attributes](https://docs.chef.io/attributes/)**
>
> An attribute is a specific detail about a node. Attributes are used by Chef Infra Client to understand:
> The current state of the node What the state of the node was at the end of the previous Chef Infra Client run What the state of the node should be...

In the setup here we use common or default attributes in a role cookbook  
and then set any environment specific overrides in an environment. That way  
there are no duplicated values in environments.

On Thu, Jun 18, 2015 at 11:24 AM, Douglas Garstang [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
wrote:

> Drew,
> 
> In our case, an environment is pinned to a physical location. For example,  
> our 'dev' and 'qa' environment is located wholly with Amazon AWS us-east-1.
> 
> If I use the chef-client cookbook as an example, it needs to have the  
> address of the chef server set. If I set that in a role, the 'chef-client'  
> role, then the address of the chef server is not consistent across all  
> locations within that role. Adding a role of 'chef-client' to a node would  
> not adequately capture the fact that in the dev environment it needs to be  
> one thing, while in the prod environment it needs to be something else.
> 
> If a role has a higher precedence than an environment, it sounds like  
> creating a base role with attributes, and then setting attributes in  
> environments would not work at all.
> 
> Doug.
> 
> On Thu, Jun 18, 2015 at 11:04 AM, Drew Blessing [drew@blessing.io](mailto:drew@blessing.io) wrote:
> 
> > You can create a base role with attributes that apply to all  
> > environments. Then set specific attributes in environments. Note that roles  
> > have a higher precedence than environments, though.
> > 
> > When you say you're heavily using environments are you overloading the  
> > definition of an environment to include locations/datacenter or something?  
> > If so, you might be abusing environments 🙂 Roles/role cookbooks or  
> > something else might be more appropriate. Something to think about.  
> > On Thu, Jun 18, 2015 at 12:48 PM Douglas Garstang \<  
> > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > 
> > > All,
> > > 
> > > I'm making pretty heavy use of environments. There's quite a fair bit of  
> > > duplication and I'd like to implement a 'base' environment, with common  
> > > attributes that apply to all environments. How would I do this?
> > > 
> > > What happens if the same attribute is defined in multiple environments?  
> > > Are they merged together or does the 'inherited' one override the 'base'  
> > > one?
> > > 
> > > Thanks,  
> > > Doug
> 
> --  
> Regards,
> 
> Douglas Garstang  
> [http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
> Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
> Cell: +1-805-340-5627

--  
Yoshi Spendiff  
Ops Engineer  
Indochino  
Mobile: +1 778 952 2025  
Email: [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)

---

<div class="post-metadata">

**Author:** ![Ranjib](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/ranjib/32/1040_2.png) [@Ranjib](https://discourse.chef.io/u/Ranjib)\
**Post date:** [June 18, 2015, 8:30pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/8 "2015-06-18T20:30:25Z")

</div>

i use environment heavily as well, and face the same problem. The trick i  
use is have a environments/common folder which container coomon things in  
yaml file (or ruby if you like) that is just data. Top level environments  
(say environments/foo.rb) can directly read that yaml, and deep\_merge! (one  
of dans many awesome works 🙂 ) that directly in default\_attributes  
method. this allows me to keep the common data and reuse it.,

hope that helps.

On Thu, Jun 18, 2015 at 10:48 AM, Douglas Garstang [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
wrote:

> All,
> 
> I'm making pretty heavy use of environments. There's quite a fair bit of  
> duplication and I'd like to implement a 'base' environment, with common  
> attributes that apply to all environments. How would I do this?
> 
> What happens if the same attribute is defined in multiple environments?  
> Are they merged together or does the 'inherited' one override the 'base'  
> one?
> 
> Thanks,  
> Doug

---

<div class="post-metadata">

**Author:** ![Douglas\_Garstang](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@Douglas\_Garstang](https://discourse.chef.io/u/Douglas_Garstang)\
**Post date:** [June 18, 2015, 8:34pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/9 "2015-06-18T20:34:29Z")

</div>

Yoshi,

So, you basically have a role called common-env (or whatever), set common  
attributes there, and then include the common-env in your run list as well  
as the functional (ie web-server, apache-server etc) role?

Douglas.

On Thu, Jun 18, 2015 at 12:52 PM, Yoshi Spendiff \<  
[yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)\> wrote:

> Roles and Environments have two attribute levels available, default and  
> override, so you can do overrides either way.
> 
> [About Attributes](https://docs.chef.io/attributes.html#attribute-precedence)
> 
> In the setup here we use common or default attributes in a role cookbook  
> and then set any environment specific overrides in an environment. That way  
> there are no duplicated values in environments.
> 
> On Thu, Jun 18, 2015 at 11:24 AM, Douglas Garstang \<  
> [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> 
> > Drew,
> > 
> > In our case, an environment is pinned to a physical location. For  
> > example, our 'dev' and 'qa' environment is located wholly with Amazon AWS  
> > us-east-1.
> > 
> > If I use the chef-client cookbook as an example, it needs to have the  
> > address of the chef server set. If I set that in a role, the 'chef-client'  
> > role, then the address of the chef server is not consistent across all  
> > locations within that role. Adding a role of 'chef-client' to a node would  
> > not adequately capture the fact that in the dev environment it needs to be  
> > one thing, while in the prod environment it needs to be something else.
> > 
> > If a role has a higher precedence than an environment, it sounds like  
> > creating a base role with attributes, and then setting attributes in  
> > environments would not work at all.
> > 
> > Doug.
> > 
> > On Thu, Jun 18, 2015 at 11:04 AM, Drew Blessing [drew@blessing.io](mailto:drew@blessing.io) wrote:
> > 
> > > You can create a base role with attributes that apply to all  
> > > environments. Then set specific attributes in environments. Note that roles  
> > > have a higher precedence than environments, though.
> > > 
> > > When you say you're heavily using environments are you overloading the  
> > > definition of an environment to include locations/datacenter or something?  
> > > If so, you might be abusing environments 🙂 Roles/role cookbooks or  
> > > something else might be more appropriate. Something to think about.  
> > > On Thu, Jun 18, 2015 at 12:48 PM Douglas Garstang \<  
> > > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > > 
> > > > All,
> > > > 
> > > > I'm making pretty heavy use of environments. There's quite a fair bit  
> > > > of duplication and I'd like to implement a 'base' environment, with common  
> > > > attributes that apply to all environments. How would I do this?
> > > > 
> > > > What happens if the same attribute is defined in multiple environments?  
> > > > Are they merged together or does the 'inherited' one override the 'base'  
> > > > one?
> > > > 
> > > > Thanks,  
> > > > Doug
> > 
> > --  
> > Regards,
> > 
> > Douglas Garstang  
> > [http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
> > Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
> > Cell: +1-805-340-5627
> 
> --  
> Yoshi Spendiff  
> Ops Engineer  
> Indochino  
> Mobile: +1 778 952 2025  
> Email: [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)

--  
Regards,

Douglas Garstang  
[http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
Cell: +1-805-340-5627

---

<div class="post-metadata">

**Author:** ![Ranjib](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/ranjib/32/1040_2.png) [@Ranjib](https://discourse.chef.io/u/Ranjib)\
**Post date:** [June 18, 2015, 8:35pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/10 "2015-06-18T20:35:58Z")

</div>

oh btw.. i dont use chef's attribute precedence heavily .. most of the  
attribute customization are spread across standard default precedence  
level, (recipe, wrappers, environments, roles ), the deep\_merge yaml trick.  
this allows me to bypass most of the so called role-env, role-recipe etc  
etc patterns, and eases deduction. I still use the higher precedence levels  
sporadically (like canary releases, CVE patches etc), more like for  
surgical cases

On Thu, Jun 18, 2015 at 1:30 PM, Ranjib Dey [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com) wrote:

> i use environment heavily as well, and face the same problem. The trick i  
> use is have a environments/common folder which container coomon things in  
> yaml file (or ruby if you like) that is just data. Top level environments  
> (say environments/foo.rb) can directly read that yaml, and deep\_merge! (one  
> of dans many awesome works 🙂 ) that directly in default\_attributes  
> method. this allows me to keep the common data and reuse it.,
> 
> hope that helps.
> 
> On Thu, Jun 18, 2015 at 10:48 AM, Douglas Garstang \<  
> [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> 
> > All,
> > 
> > I'm making pretty heavy use of environments. There's quite a fair bit of  
> > duplication and I'd like to implement a 'base' environment, with common  
> > attributes that apply to all environments. How would I do this?
> > 
> > What happens if the same attribute is defined in multiple environments?  
> > Are they merged together or does the 'inherited' one override the 'base'  
> > one?
> > 
> > Thanks,  
> > Doug

---

<div class="post-metadata">

**Author:** ![Ranjib](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/ranjib/32/1040_2.png) [@Ranjib](https://discourse.chef.io/u/Ranjib)\
**Post date:** [June 18, 2015, 8:44pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/11 "2015-06-18T20:44:06Z")

</div>

yeah exactly. i dont follow those pattern, in fact i cant recall reading  
many of them, after sometime there were too many i could not connect the  
dots. I try to use the original chef style.,. which is single repo for the  
org, with berks integration so that we can churn out community cookbooks  
(both ways, consume and publish), as well as if any service /app team wants  
to take over their cookbooks, they are more than welcome. roles are more  
like aggregation units, that assemble community/core stuff along with  
service ..and attribute driven customization mostly uses default  
precedence, if they are service specific, they go to roles (like nginx  
connection limit, db memory settings), if the customizations are global  
(like dns, ldap) they go to environment. some of these cross environments  
settings are common hence the yaml trick, else we would have something like  
base env. But till now i never felt like we'll need deeper nesting (not  
sure if its good as well),, general topology of chef domain objects  
(cookbook, role, environments) is similar to standard OOP strategy.. have  
no more than 3 (shallow ) nesting (roles, envs).. with lot of mixins  
(cookbooks). Some of the top level mixins (wrapper or applications  
cookbooks) needs to be bit more intelligent hold more logic,, they  
distribute that logic between hwrps,lwrps, modules, gems etc.  
hth

On Thu, Jun 18, 2015 at 1:34 PM, Douglas Garstang [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
wrote:

> Yoshi,
> 
> So, you basically have a role called common-env (or whatever), set common  
> attributes there, and then include the common-env in your run list as well  
> as the functional (ie web-server, apache-server etc) role?
> 
> Douglas.
> 
> On Thu, Jun 18, 2015 at 12:52 PM, Yoshi Spendiff \<  
> [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)\> wrote:
> 
> > Roles and Environments have two attribute levels available, default and  
> > override, so you can do overrides either way.
> > 
> > [About Attributes](https://docs.chef.io/attributes.html#attribute-precedence)
> > 
> > In the setup here we use common or default attributes in a role cookbook  
> > and then set any environment specific overrides in an environment. That way  
> > there are no duplicated values in environments.
> > 
> > On Thu, Jun 18, 2015 at 11:24 AM, Douglas Garstang \<  
> > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > 
> > > Drew,
> > > 
> > > In our case, an environment is pinned to a physical location. For  
> > > example, our 'dev' and 'qa' environment is located wholly with Amazon AWS  
> > > us-east-1.
> > > 
> > > If I use the chef-client cookbook as an example, it needs to have the  
> > > address of the chef server set. If I set that in a role, the 'chef-client'  
> > > role, then the address of the chef server is not consistent across all  
> > > locations within that role. Adding a role of 'chef-client' to a node would  
> > > not adequately capture the fact that in the dev environment it needs to be  
> > > one thing, while in the prod environment it needs to be something else.
> > > 
> > > If a role has a higher precedence than an environment, it sounds like  
> > > creating a base role with attributes, and then setting attributes in  
> > > environments would not work at all.
> > > 
> > > Doug.
> > > 
> > > On Thu, Jun 18, 2015 at 11:04 AM, Drew Blessing [drew@blessing.io](mailto:drew@blessing.io)  
> > > wrote:
> > > 
> > > > You can create a base role with attributes that apply to all  
> > > > environments. Then set specific attributes in environments. Note that roles  
> > > > have a higher precedence than environments, though.
> > > > 
> > > > When you say you're heavily using environments are you overloading the  
> > > > definition of an environment to include locations/datacenter or something?  
> > > > If so, you might be abusing environments 🙂 Roles/role cookbooks or  
> > > > something else might be more appropriate. Something to think about.  
> > > > On Thu, Jun 18, 2015 at 12:48 PM Douglas Garstang \<  
> > > > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > > > 
> > > > > All,
> > > > > 
> > > > > I'm making pretty heavy use of environments. There's quite a fair bit  
> > > > > of duplication and I'd like to implement a 'base' environment, with common  
> > > > > attributes that apply to all environments. How would I do this?
> > > > > 
> > > > > What happens if the same attribute is defined in multiple  
> > > > > environments? Are they merged together or does the 'inherited' one override  
> > > > > the 'base' one?
> > > > > 
> > > > > Thanks,  
> > > > > Doug
> > > 
> > > --  
> > > Regards,
> > > 
> > > Douglas Garstang  
> > > [http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
> > > Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
> > > Cell: +1-805-340-5627
> > 
> > --  
> > Yoshi Spendiff  
> > Ops Engineer  
> > Indochino  
> > Mobile: +1 778 952 2025  
> > Email: [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)
> 
> --  
> Regards,
> 
> Douglas Garstang  
> [http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
> Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
> Cell: +1-805-340-5627

---

<div class="post-metadata">

**Author:** ![Douglas\_Garstang](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@Douglas\_Garstang](https://discourse.chef.io/u/Douglas_Garstang)\
**Post date:** [June 18, 2015, 8:49pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/12 "2015-06-18T20:49:11Z")

</div>

Sounds .... complicated.

I don't think I have a complex enough environment to justify that yet.  
Looking at the attributes precedence docs, it looks like I could set common  
attributes as default attributes in a role (#4) and then override with a  
override attribute in an environment (#12). In this situation though, would  
the two hashes me merged together?

Doug.

On Thu, Jun 18, 2015 at 1:35 PM, Ranjib Dey [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com) wrote:

> oh btw.. i dont use chef's attribute precedence heavily .. most of the  
> attribute customization are spread across standard default precedence  
> level, (recipe, wrappers, environments, roles ), the deep\_merge yaml trick.  
> this allows me to bypass most of the so called role-env, role-recipe etc  
> etc patterns, and eases deduction. I still use the higher precedence levels  
> sporadically (like canary releases, CVE patches etc), more like for  
> surgical cases
> 
> On Thu, Jun 18, 2015 at 1:30 PM, Ranjib Dey [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com) wrote:
> 
> > i use environment heavily as well, and face the same problem. The trick i  
> > use is have a environments/common folder which container coomon things in  
> > yaml file (or ruby if you like) that is just data. Top level environments  
> > (say environments/foo.rb) can directly read that yaml, and deep\_merge! (one  
> > of dans many awesome works 🙂 ) that directly in default\_attributes  
> > method. this allows me to keep the common data and reuse it.,
> > 
> > hope that helps.
> > 
> > On Thu, Jun 18, 2015 at 10:48 AM, Douglas Garstang \<  
> > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > 
> > > All,
> > > 
> > > I'm making pretty heavy use of environments. There's quite a fair bit of  
> > > duplication and I'd like to implement a 'base' environment, with common  
> > > attributes that apply to all environments. How would I do this?
> > > 
> > > What happens if the same attribute is defined in multiple environments?  
> > > Are they merged together or does the 'inherited' one override the 'base'  
> > > one?
> > > 
> > > Thanks,  
> > > Doug

--  
Regards,

Douglas Garstang  
[http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
Cell: +1-805-340-5627

---

<div class="post-metadata">

**Author:** ![Yoshi\_Spendiff](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/yoshi_spendiff/32/13_2.png) [@Yoshi\_Spendiff](https://discourse.chef.io/u/Yoshi_Spendiff)\
**Post date:** [June 18, 2015, 8:52pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/13 "2015-06-18T20:52:16Z")

</div>

I have a role cookbook and a base cookbook. My nodes only ever have one  
recipe from the role cookbook and the default recipe from the base  
cookbook. These two recipes do everything I need to configure my nodes,  
including calling any base cookbooks (in which case default attributes are  
overridden in the role) and wrapper cookbooks (attributes overridden in the  
wrapper if they're defaults for the company).

Anything that is unique to the company goes in this role cookbook and  
anything that is unique to an environment goes in the environment. Because  
I'm using cookbook default attributes they're easy to override anywhere.

Some people (in fact Chef recommend) taking this a step further and having  
a cookbook per role instead of a role cookbook with a recipe per role.

On Thu, Jun 18, 2015 at 1:44 PM, Ranjib Dey [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com) wrote:

> yeah exactly. i dont follow those pattern, in fact i cant recall reading  
> many of them, after sometime there were too many i could not connect the  
> dots. I try to use the original chef style.,. which is single repo for the  
> org, with berks integration so that we can churn out community cookbooks  
> (both ways, consume and publish), as well as if any service /app team wants  
> to take over their cookbooks, they are more than welcome. roles are more  
> like aggregation units, that assemble community/core stuff along with  
> service ..and attribute driven customization mostly uses default  
> precedence, if they are service specific, they go to roles (like nginx  
> connection limit, db memory settings), if the customizations are global  
> (like dns, ldap) they go to environment. some of these cross environments  
> settings are common hence the yaml trick, else we would have something like  
> base env. But till now i never felt like we'll need deeper nesting (not  
> sure if its good as well),, general topology of chef domain objects  
> (cookbook, role, environments) is similar to standard OOP strategy.. have  
> no more than 3 (shallow ) nesting (roles, envs).. with lot of mixins  
> (cookbooks). Some of the top level mixins (wrapper or applications  
> cookbooks) needs to be bit more intelligent hold more logic,, they  
> distribute that logic between hwrps,lwrps, modules, gems etc.  
> hth
> 
> On Thu, Jun 18, 2015 at 1:34 PM, Douglas Garstang \<[doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)
> 
> > wrote:
> 
> > Yoshi,
> > 
> > So, you basically have a role called common-env (or whatever), set common  
> > attributes there, and then include the common-env in your run list as well  
> > as the functional (ie web-server, apache-server etc) role?
> > 
> > Douglas.
> > 
> > On Thu, Jun 18, 2015 at 12:52 PM, Yoshi Spendiff \<  
> > [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)\> wrote:
> > 
> > > Roles and Environments have two attribute levels available, default and  
> > > override, so you can do overrides either way.
> > > 
> > > [About Attributes](https://docs.chef.io/attributes.html#attribute-precedence)
> > > 
> > > In the setup here we use common or default attributes in a role cookbook  
> > > and then set any environment specific overrides in an environment. That way  
> > > there are no duplicated values in environments.
> > > 
> > > On Thu, Jun 18, 2015 at 11:24 AM, Douglas Garstang \<  
> > > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > > 
> > > > Drew,
> > > > 
> > > > In our case, an environment is pinned to a physical location. For  
> > > > example, our 'dev' and 'qa' environment is located wholly with Amazon AWS  
> > > > us-east-1.
> > > > 
> > > > If I use the chef-client cookbook as an example, it needs to have the  
> > > > address of the chef server set. If I set that in a role, the 'chef-client'  
> > > > role, then the address of the chef server is not consistent across all  
> > > > locations within that role. Adding a role of 'chef-client' to a node would  
> > > > not adequately capture the fact that in the dev environment it needs to be  
> > > > one thing, while in the prod environment it needs to be something else.
> > > > 
> > > > If a role has a higher precedence than an environment, it sounds like  
> > > > creating a base role with attributes, and then setting attributes in  
> > > > environments would not work at all.
> > > > 
> > > > Doug.
> > > > 
> > > > On Thu, Jun 18, 2015 at 11:04 AM, Drew Blessing [drew@blessing.io](mailto:drew@blessing.io)  
> > > > wrote:
> > > > 
> > > > > You can create a base role with attributes that apply to all  
> > > > > environments. Then set specific attributes in environments. Note that roles  
> > > > > have a higher precedence than environments, though.
> > > > > 
> > > > > When you say you're heavily using environments are you overloading the  
> > > > > definition of an environment to include locations/datacenter or something?  
> > > > > If so, you might be abusing environments 🙂 Roles/role cookbooks or  
> > > > > something else might be more appropriate. Something to think about.  
> > > > > On Thu, Jun 18, 2015 at 12:48 PM Douglas Garstang \<  
> > > > > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > > > > 
> > > > > > All,
> > > > > > 
> > > > > > I'm making pretty heavy use of environments. There's quite a fair bit  
> > > > > > of duplication and I'd like to implement a 'base' environment, with common  
> > > > > > attributes that apply to all environments. How would I do this?
> > > > > > 
> > > > > > What happens if the same attribute is defined in multiple  
> > > > > > environments? Are they merged together or does the 'inherited' one override  
> > > > > > the 'base' one?
> > > > > > 
> > > > > > Thanks,  
> > > > > > Doug
> > > > 
> > > > --  
> > > > Regards,
> > > > 
> > > > Douglas Garstang  
> > > > [http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
> > > > Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
> > > > Cell: +1-805-340-5627
> > > 
> > > --  
> > > Yoshi Spendiff  
> > > Ops Engineer  
> > > Indochino  
> > > Mobile: +1 778 952 2025  
> > > Email: [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)
> > 
> > --  
> > Regards,
> > 
> > Douglas Garstang  
> > [http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
> > Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
> > Cell: +1-805-340-5627

--  
Yoshi Spendiff  
Ops Engineer  
Indochino  
Mobile: +1 778 952 2025  
Email: [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)

---

<div class="post-metadata">

**Author:** ![Yoshi\_Spendiff](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/yoshi_spendiff/32/13_2.png) [@Yoshi\_Spendiff](https://discourse.chef.io/u/Yoshi_Spendiff)\
**Post date:** [June 18, 2015, 8:53pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/14 "2015-06-18T20:53:09Z")

</div>

Everything gets merged together. Your attribute set at the end is the  
result of all levels and locations being merged together and the highest  
precedence winning.

On Thu, Jun 18, 2015 at 1:49 PM, Douglas Garstang [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
wrote:

> Sounds .... complicated.
> 
> I don't think I have a complex enough environment to justify that yet.  
> Looking at the attributes precedence docs, it looks like I could set common  
> attributes as default attributes in a role (#4) and then override with a  
> override attribute in an environment (#12). In this situation though, would  
> the two hashes me merged together?
> 
> Doug.
> 
> On Thu, Jun 18, 2015 at 1:35 PM, Ranjib Dey [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com) wrote:
> 
> > oh btw.. i dont use chef's attribute precedence heavily .. most of the  
> > attribute customization are spread across standard default precedence  
> > level, (recipe, wrappers, environments, roles ), the deep\_merge yaml trick.  
> > this allows me to bypass most of the so called role-env, role-recipe etc  
> > etc patterns, and eases deduction. I still use the higher precedence levels  
> > sporadically (like canary releases, CVE patches etc), more like for  
> > surgical cases
> > 
> > On Thu, Jun 18, 2015 at 1:30 PM, Ranjib Dey [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com) wrote:
> > 
> > > i use environment heavily as well, and face the same problem. The trick  
> > > i use is have a environments/common folder which container coomon things in  
> > > yaml file (or ruby if you like) that is just data. Top level environments  
> > > (say environments/foo.rb) can directly read that yaml, and deep\_merge! (one  
> > > of dans many awesome works 🙂 ) that directly in default\_attributes  
> > > method. this allows me to keep the common data and reuse it.,
> > > 
> > > hope that helps.
> > > 
> > > On Thu, Jun 18, 2015 at 10:48 AM, Douglas Garstang \<  
> > > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > > 
> > > > All,
> > > > 
> > > > I'm making pretty heavy use of environments. There's quite a fair bit  
> > > > of duplication and I'd like to implement a 'base' environment, with common  
> > > > attributes that apply to all environments. How would I do this?
> > > > 
> > > > What happens if the same attribute is defined in multiple environments?  
> > > > Are they merged together or does the 'inherited' one override the 'base'  
> > > > one?
> > > > 
> > > > Thanks,  
> > > > Doug
> 
> --  
> Regards,
> 
> Douglas Garstang  
> [http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
> Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
> Cell: +1-805-340-5627

--  
Yoshi Spendiff  
Ops Engineer  
Indochino  
Mobile: +1 778 952 2025  
Email: [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)

---

<div class="post-metadata">

**Author:** ![Galen\_Emery](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/galen_emery/32/11_2.png) [@Galen\_Emery](https://discourse.chef.io/u/Galen_Emery)\
**Post date:** [June 18, 2015, 8:56pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/15 "2015-06-18T20:56:04Z")

</div>

Doug,

the levels you suggested are the ones we typically recommend.

The way I teach people is the following:  
Cookbook attributes file: use default.  
Roles: Use Default  
Environments: Use Override.

There's a bunch of other precedence levels and while helpful for debug, can  
drive you nuts if you're using in production.

On Thu, Jun 18, 2015 at 1:53 PM, Yoshi Spendiff \<  
[yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)\> wrote:

> Everything gets merged together. Your attribute set at the end is the  
> result of all levels and locations being merged together and the highest  
> precedence winning.
> 
> On Thu, Jun 18, 2015 at 1:49 PM, Douglas Garstang \<[doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)
> 
> > wrote:
> 
> > Sounds .... complicated.
> > 
> > I don't think I have a complex enough environment to justify that yet.  
> > Looking at the attributes precedence docs, it looks like I could set common  
> > attributes as default attributes in a role (#4) and then override with a  
> > override attribute in an environment (#12). In this situation though, would  
> > the two hashes me merged together?
> > 
> > Doug.
> > 
> > On Thu, Jun 18, 2015 at 1:35 PM, Ranjib Dey [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com) wrote:
> > 
> > > oh btw.. i dont use chef's attribute precedence heavily .. most of the  
> > > attribute customization are spread across standard default precedence  
> > > level, (recipe, wrappers, environments, roles ), the deep\_merge yaml trick.  
> > > this allows me to bypass most of the so called role-env, role-recipe etc  
> > > etc patterns, and eases deduction. I still use the higher precedence levels  
> > > sporadically (like canary releases, CVE patches etc), more like for  
> > > surgical cases
> > > 
> > > On Thu, Jun 18, 2015 at 1:30 PM, Ranjib Dey [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com)  
> > > wrote:
> > > 
> > > > i use environment heavily as well, and face the same problem. The trick  
> > > > i use is have a environments/common folder which container coomon things in  
> > > > yaml file (or ruby if you like) that is just data. Top level environments  
> > > > (say environments/foo.rb) can directly read that yaml, and deep\_merge! (one  
> > > > of dans many awesome works 🙂 ) that directly in default\_attributes  
> > > > method. this allows me to keep the common data and reuse it.,
> > > > 
> > > > hope that helps.
> > > > 
> > > > On Thu, Jun 18, 2015 at 10:48 AM, Douglas Garstang \<  
> > > > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > > > 
> > > > > All,
> > > > > 
> > > > > I'm making pretty heavy use of environments. There's quite a fair bit  
> > > > > of duplication and I'd like to implement a 'base' environment, with common  
> > > > > attributes that apply to all environments. How would I do this?
> > > > > 
> > > > > What happens if the same attribute is defined in multiple  
> > > > > environments? Are they merged together or does the 'inherited' one override  
> > > > > the 'base' one?
> > > > > 
> > > > > Thanks,  
> > > > > Doug
> > 
> > --  
> > Regards,
> > 
> > Douglas Garstang  
> > [http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
> > Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
> > Cell: +1-805-340-5627
> 
> --  
> Yoshi Spendiff  
> Ops Engineer  
> Indochino  
> Mobile: +1 778 952 2025  
> Email: [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)

--  
Galen Emery

---

<div class="post-metadata">

**Author:** ![tknerr](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/tknerr/32/21_2.png) [@tknerr](https://discourse.chef.io/u/tknerr)\
**Post date:** [June 18, 2015, 10:05pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/16 "2015-06-18T22:05:13Z")

</div>

Hey Ranjib,

mind sharing an example snippet on how you do that?

Thought that includes were not possible with json environment files, but  
yes, indeed they can be ruby dsl as well...

Cheers, Torben  
Am 18.06.2015 22:30 schrieb "Ranjib Dey" [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com):

> i use environment heavily as well, and face the same problem. The trick i  
> use is have a environments/common folder which container coomon things in  
> yaml file (or ruby if you like) that is just data. Top level environments  
> (say environments/foo.rb) can directly read that yaml, and deep\_merge! (one  
> of dans many awesome works 🙂 ) that directly in default\_attributes  
> method. this allows me to keep the common data and reuse it.,
> 
> hope that helps.
> 
> On Thu, Jun 18, 2015 at 10:48 AM, Douglas Garstang \<  
> [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> 
> > All,
> > 
> > I'm making pretty heavy use of environments. There's quite a fair bit of  
> > duplication and I'd like to implement a 'base' environment, with common  
> > attributes that apply to all environments. How would I do this?
> > 
> > What happens if the same attribute is defined in multiple environments?  
> > Are they merged together or does the 'inherited' one override the 'base'  
> > one?
> > 
> > Thanks,  
> > Doug

---

<div class="post-metadata">

**Author:** ![Ranjib](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/ranjib/32/1040_2.png) [@Ranjib](https://discourse.chef.io/u/Ranjib)\
**Post date:** [June 18, 2015, 10:16pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/17 "2015-06-18T22:16:09Z")

</div>

sure:

> <https://gist.github.com/ranjib/2f7e1482a3ac8f6e5bfc>

On Thu, Jun 18, 2015 at 3:05 PM, Torben Knerr [mail@tknerr.de](mailto:mail@tknerr.de) wrote:

> Hey Ranjib,
> 
> mind sharing an example snippet on how you do that?
> 
> Thought that includes were not possible with json environment files, but  
> yes, indeed they can be ruby dsl as well...
> 
> Cheers, Torben  
> Am 18.06.2015 22:30 schrieb "Ranjib Dey" [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com):
> 
> > i use environment heavily as well, and face the same problem. The trick i  
> > use is have a environments/common folder which container coomon things in  
> > yaml file (or ruby if you like) that is just data. Top level environments  
> > (say environments/foo.rb) can directly read that yaml, and deep\_merge! (one  
> > of dans many awesome works 🙂 ) that directly in default\_attributes  
> > method. this allows me to keep the common data and reuse it.,
> > 
> > hope that helps.
> > 
> > On Thu, Jun 18, 2015 at 10:48 AM, Douglas Garstang \<  
> > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > 
> > > All,
> > > 
> > > I'm making pretty heavy use of environments. There's quite a fair bit of  
> > > duplication and I'd like to implement a 'base' environment, with common  
> > > attributes that apply to all environments. How would I do this?
> > > 
> > > What happens if the same attribute is defined in multiple environments?  
> > > Are they merged together or does the 'inherited' one override the 'base'  
> > > one?
> > > 
> > > Thanks,  
> > > Doug

---

<div class="post-metadata">

**Author:** ![tknerr](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/tknerr/32/21_2.png) [@tknerr](https://discourse.chef.io/u/tknerr)\
**Post date:** [June 18, 2015, 10:23pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/18 "2015-06-18T22:23:25Z")

</div>

Awesome, thanks Ranjib!  
Am 19.06.2015 00:16 schrieb "Ranjib Dey" [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com):

> sure:
> 
> [Consuming common datra across environments using Chef's ruby environment DSL · GitHub](https://gist.github.com/ranjib/2f7e1482a3ac8f6e5bfc)
> 
> On Thu, Jun 18, 2015 at 3:05 PM, Torben Knerr [mail@tknerr.de](mailto:mail@tknerr.de) wrote:
> 
> > Hey Ranjib,
> > 
> > mind sharing an example snippet on how you do that?
> > 
> > Thought that includes were not possible with json environment files, but  
> > yes, indeed they can be ruby dsl as well...
> > 
> > Cheers, Torben  
> > Am 18.06.2015 22:30 schrieb "Ranjib Dey" [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com):
> > 
> > > i use environment heavily as well, and face the same problem. The trick  
> > > i use is have a environments/common folder which container coomon things in  
> > > yaml file (or ruby if you like) that is just data. Top level environments  
> > > (say environments/foo.rb) can directly read that yaml, and deep\_merge! (one  
> > > of dans many awesome works 🙂 ) that directly in default\_attributes  
> > > method. this allows me to keep the common data and reuse it.,
> > > 
> > > hope that helps.
> > > 
> > > On Thu, Jun 18, 2015 at 10:48 AM, Douglas Garstang \<  
> > > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > > 
> > > > All,
> > > > 
> > > > I'm making pretty heavy use of environments. There's quite a fair bit  
> > > > of duplication and I'd like to implement a 'base' environment, with common  
> > > > attributes that apply to all environments. How would I do this?
> > > > 
> > > > What happens if the same attribute is defined in multiple environments?  
> > > > Are they merged together or does the 'inherited' one override the 'base'  
> > > > one?
> > > > 
> > > > Thanks,  
> > > > Doug

---

<div class="post-metadata">

**Author:** ![Philoliva8](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.chef.io/philoliva8/32/57_2.png) [@Philoliva8](https://discourse.chef.io/u/Philoliva8)\
**Post date:** [June 18, 2015, 10:26pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/19 "2015-06-18T22:26:02Z")

</div>

Doug,

You may know this but since its been suggested to play around with precedence levels for attributes. Might be worth mentioning that array attributes are always union merged. I tend to stick with hashes whenever possible in my cookbooks because of this behaviour. But if your heavily using community cookbooks you might run into this.

I bookmarked this post to help explain it to others in my organization as it seems to always confuse a lot of people new to chef.

‎[Arrays and Chef Attributes – Noah Kantrowitz](https://coderanger.net/arrays-and-chef/)

Regards,Phil

**From:** Torben Knerr‎ **Sent:** Thursday, June 18, 2015 6:05 PM **To:** [chef@lists.opscode.com](mailto:chef@lists.opscode.com) **Reply To:** [chef@lists.opscode.com](mailto:chef@lists.opscode.com) **Subject:** [chef] Re: Re: Environment Inheritence

Hey Ranjib,

mind sharing an example snippet on how you do that?

Thought that includes were not possible with json environment files, but yes, indeed they can be ruby dsl as well...

Cheers, Torben

Am 18.06.2015 22:30 schrieb "Ranjib Dey" \<[dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com)\>:

> i use environment heavily as well, and face the same problem. The trick i use is have a environments/common folder which container coomon things in yaml file (or ruby if you like) that is just data. Top level environments (say environments/foo.rb) can directly read that yaml, and deep\_merge! (one of dans many awesome works :-) ) that directly in default\_attributes method. this allows me to keep the common data and reuse it.,
> 
> hope that helps.
> 
> On Thu, Jun 18, 2015 at 10:48 AM, Douglas Garstang \<[doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> 
> > All,
> > 
> > I'm making pretty heavy use of environments. There's quite a fair bit of duplication and I'd like to implement a 'base' environment, with common attributes that apply to all environments. How would I do this?
> > 
> > What happens if the same attribute is defined in multiple environments? Are they merged together or does the 'inherited' one override the 'base' one?
> > 
> > Thanks,
> > 
> > Doug

---

<div class="post-metadata">

**Author:** ![Douglas\_Garstang](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@Douglas\_Garstang](https://discourse.chef.io/u/Douglas_Garstang)\
**Post date:** [June 18, 2015, 10:26pm UTC](https://discourse.chef.io/t/environment-inheritence/6676/20 "2015-06-18T22:26:59Z")

</div>

Thanks Galen.

I've already hit a snag with this approach. I'm setting common attributes  
in a recipe (#2), and overriding environmental attributes in an environment  
(#12). However, I have a cookbook that needs to modify a single attribute  
to the openssh cookbook. I don't know where I could put this. There's only  
2 places it can go that have higher precedence than #12, and neither of  
those are a role. :~(

Doug.

On Thu, Jun 18, 2015 at 1:56 PM, Galen Emery [galen@getchef.com](mailto:galen@getchef.com) wrote:

> Doug,
> 
> the levels you suggested are the ones we typically recommend.
> 
> The way I teach people is the following:  
> Cookbook attributes file: use default.  
> Roles: Use Default  
> Environments: Use Override.
> 
> There's a bunch of other precedence levels and while helpful for debug,  
> can drive you nuts if you're using in production.
> 
> On Thu, Jun 18, 2015 at 1:53 PM, Yoshi Spendiff \<  
> [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)\> wrote:
> 
> > Everything gets merged together. Your attribute set at the end is the  
> > result of all levels and locations being merged together and the highest  
> > precedence winning.
> > 
> > On Thu, Jun 18, 2015 at 1:49 PM, Douglas Garstang \<  
> > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > 
> > > Sounds .... complicated.
> > > 
> > > I don't think I have a complex enough environment to justify that yet.  
> > > Looking at the attributes precedence docs, it looks like I could set common  
> > > attributes as default attributes in a role (#4) and then override with a  
> > > override attribute in an environment (#12). In this situation though, would  
> > > the two hashes me merged together?
> > > 
> > > Doug.
> > > 
> > > On Thu, Jun 18, 2015 at 1:35 PM, Ranjib Dey [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com)  
> > > wrote:
> > > 
> > > > oh btw.. i dont use chef's attribute precedence heavily .. most of the  
> > > > attribute customization are spread across standard default precedence  
> > > > level, (recipe, wrappers, environments, roles ), the deep\_merge yaml trick.  
> > > > this allows me to bypass most of the so called role-env, role-recipe etc  
> > > > etc patterns, and eases deduction. I still use the higher precedence levels  
> > > > sporadically (like canary releases, CVE patches etc), more like for  
> > > > surgical cases
> > > > 
> > > > On Thu, Jun 18, 2015 at 1:30 PM, Ranjib Dey [dey.ranjib@gmail.com](mailto:dey.ranjib@gmail.com)  
> > > > wrote:
> > > > 
> > > > > i use environment heavily as well, and face the same problem. The  
> > > > > trick i use is have a environments/common folder which container coomon  
> > > > > things in yaml file (or ruby if you like) that is just data. Top level  
> > > > > environments (say environments/foo.rb) can directly read that yaml, and  
> > > > > deep\_merge! (one of dans many awesome works 🙂 ) that directly in  
> > > > > default\_attributes method. this allows me to keep the common data and reuse  
> > > > > it.,
> > > > > 
> > > > > hope that helps.
> > > > > 
> > > > > On Thu, Jun 18, 2015 at 10:48 AM, Douglas Garstang \<  
> > > > > [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)\> wrote:
> > > > > 
> > > > > > All,
> > > > > > 
> > > > > > I'm making pretty heavy use of environments. There's quite a fair bit  
> > > > > > of duplication and I'd like to implement a 'base' environment, with common  
> > > > > > attributes that apply to all environments. How would I do this?
> > > > > > 
> > > > > > What happens if the same attribute is defined in multiple  
> > > > > > environments? Are they merged together or does the 'inherited' one override  
> > > > > > the 'base' one?
> > > > > > 
> > > > > > Thanks,  
> > > > > > Doug
> > > 
> > > --  
> > > Regards,
> > > 
> > > Douglas Garstang  
> > > [http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
> > > Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
> > > Cell: +1-805-340-5627
> > 
> > --  
> > Yoshi Spendiff  
> > Ops Engineer  
> > Indochino  
> > Mobile: +1 778 952 2025  
> > Email: [yoshi.spendiff@indochino.com](mailto:yoshi.spendiff@indochino.com)
> 
> --  
> Galen Emery

--  
Regards,

Douglas Garstang  
[http://www.linkedin.com/in/garstang](http://www.linkedin.com/in/garstang)  
Email: [doug.garstang@gmail.com](mailto:doug.garstang@gmail.com)  
Cell: +1-805-340-5627

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