terraform

History

Martin Atkins 86c02d5c35 command: "terraform init" can partially initialize for 0.12upgrade There are a few constructs from 0.11 and prior that cause 0.12 parsing to fail altogether, which previously created a chicken/egg problem because we need to install the providers in order to run "terraform 0.12upgrade" and thus fix the problem. This changes "terraform init" to use the new "early configuration" loader for module and provider installation. This is built on the more permissive parser in the terraform-config-inspect package, and so it allows us to read out the top-level blocks from the configuration while accepting legacy HCL syntax. In the long run this will let us do version compatibility detection before attempting a "real" config load, giving us better error messages for any future syntax additions, but in the short term the key thing is that it allows us to install the dependencies even if the configuration isn't fully valid. Because backend init still requires full configuration, this introduces a new mode of terraform init where it detects heuristically if it seems like we need to do a configuration upgrade and does a partial init if so, before finally directing the user to run "terraform 0.12upgrade" before running any other commands. The heuristic here is based on two assumptions: - If the "early" loader finds no errors but the normal loader does, the configuration is likely to be valid for Terraform 0.11 but not 0.12. - If there's already a version constraint in the configuration that excludes Terraform versions prior to v0.12 then the configuration is probably _already_ upgraded and so it's just a normal syntax error, even if the early loader didn't detect it. Once the upgrade process is removed in 0.13.0 (users will be required to go stepwise 0.11 -> 0.12 -> 0.13 to upgrade after that), some of this can be simplified to remove that special mode, but the idea of doing the dependency version checks against the liberal parser will remain valuable to increase our chances of reporting version-based incompatibilities rather than syntax errors as we add new features in future.	8 years ago
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main.tf	command: "terraform init" can partially initialize for 0.12upgrade	8 years ago

Martin Atkins 86c02d5c35 command: "terraform init" can partially initialize for 0.12upgrade

There are a few constructs from 0.11 and prior that cause 0.12 parsing to
fail altogether, which previously created a chicken/egg problem because
we need to install the providers in order to run "terraform 0.12upgrade"
and thus fix the problem.

This changes "terraform init" to use the new "early configuration" loader
for module and provider installation. This is built on the more permissive
parser in the terraform-config-inspect package, and so it allows us to
read out the top-level blocks from the configuration while accepting
legacy HCL syntax.

In the long run this will let us do version compatibility detection before
attempting a "real" config load, giving us better error messages for any
future syntax additions, but in the short term the key thing is that it
allows us to install the dependencies even if the configuration isn't
fully valid.

Because backend init still requires full configuration, this introduces a
new mode of terraform init where it detects heuristically if it seems like
we need to do a configuration upgrade and does a partial init if so,
before finally directing the user to run "terraform 0.12upgrade" before
running any other commands.

The heuristic here is based on two assumptions:
- If the "early" loader finds no errors but the normal loader does, the
  configuration is likely to be valid for Terraform 0.11 but not 0.12.
- If there's already a version constraint in the configuration that
  excludes Terraform versions prior to v0.12 then the configuration is
  probably _already_ upgraded and so it's just a normal syntax error,
  even if the early loader didn't detect it.

Once the upgrade process is removed in 0.13.0 (users will be required to
go stepwise 0.11 -> 0.12 -> 0.13 to upgrade after that), some of this can
be simplified to remove that special mode, but the idea of doing the
dependency version checks against the liberal parser will remain valuable
to increase our chances of reporting version-based incompatibilities
rather than syntax errors as we add new features in future.

main.tf

command: "terraform init" can partially initialize for 0.12upgrade