none that I am aware of. Terraform is decent if you like declarative style,
and does not control the whole fleet but only provision/de-provision (i.e.
dont use state). If you like programmability, sparkle formation is still
your best bet.
I dont think we’ll have tools with larger community around this usecase.
Cause most users who churn lots of hosts, are likely to use cloud specific stuff
(cloud formation, or azure specific gears) either from CI or some ancillary
services. Given that there exists low level libraries like fog, boto and
jcloud it is relatively easier to roll something custom. And the
requirement of having something framework style (not library) as well as
cross cloud is slim. We had this requirement, and we rolled our own
provisioning gears on top of knife bootstrap. Existing stuff didnt fit, and
we didnt want to wait.
Concurrent provisioning has gremlins if done on chef provisioning layer,
due to chef config being global and other known ruby gotchas.
I think among the current solution, if terraform add mruby based plugins,
that will open up the possibility to have a turing complete DSL beyond the
json/hcl/yaml based stuff. … but thats some work , & hashicorp have to
be fine with something like that (considering you want this mainstream).