Terraform 0.7 introduces lists and maps as first-class values for
variables, in addition to string values which were previously available.
However, there was previously no way to override the default value of a
list or map, and the functionality for overriding specific map keys was
broken.
Using the environment variable method for setting variable values, there
was previously no way to give a variable a value of a list or map. These
now support HCL for individual values - specifying:
TF_VAR_test='["Hello", "World"]'
will set the variable `test` to a two-element list containing "Hello"
and "World". Specifying
TF_VAR_test_map='{"Hello = "World", "Foo" = "bar"}'
will set the variable `test_map` to a two-element map with keys "Hello"
and "Foo", and values "World" and "bar" respectively.
The same logic is applied to `-var` flags, and the file parsed by
`-var-files` ("autoVariables").
Note that care must be taken to not run into shell expansion for `-var-`
flags and environment variables.
We also merge map keys where appropriate. The override syntax has
changed (to be noted in CHANGELOG as a breaking change), so several
tests needed their syntax updating from the old `amis.us-east-1 =
"newValue"` style to `amis = "{ "us-east-1" = "newValue"}"` style as
defined in TF-002.
In order to continue supporting the `-var "foo=bar"` type of variable
flag (which is not valid HCL), a special case error is checked after HCL
parsing fails, and the old code path runs instead.
This is the first step in allowing overrides of map and list variables.
We convert Context.variables to map[string]interface{} from
map[string]string and fix up all the call sites.
When working from an existing plan, we weren't setting the PathOut field
for a LocalState. This required adding an outPath argument to the
StateFromPlan function to avoid having to introspect the returned
state.State interface to find the appropriate field.
To test we run a plan first and provide the new plan to apply with
`-state-out` set.
This adds a field terraform_version to the state that represents the
Terraform version that wrote that state. If Terraform encounters a state
written by a future version, it will error. You must use at least the
version that wrote that state.
Internally we have fields to override this behavior (StateFutureAllowed),
but I chose not to expose them as CLI flags, since the user can just
modify the state directly. This is tricky, but should be tricky to
represent the horrible disaster that can happen by enabling it.
We didn't have to bump the state format version since the absense of the
field means it was written by version "0.0.0" which will always be
older. In effect though this change will always apply to version 2 of
the state since it appears in 0.7 which bumped the version for other
purposes.
This introduces the terraform state list command to list the resources
within a state. This is the first of many state management commands to
come into 0.7.
This is the first command of many to come that is considered a
"plumbing" command within Terraform (see "plumbing vs porcelain":
http://git.661346.n2.nabble.com/what-are-plumbing-and-porcelain-td2190639.html).
As such, this PR also introduces a bunch of groundwork to support
plumbing commands.
The main changes:
- Main command output is changed to split "common" and "uncommon"
commands.
- mitchellh/cli is updated to support nested subcommands, since
terraform state list is a nested subcommand.
- terraform.StateFilter is introduced as a way in core to filter/search
the state files. This is very basic currently but I expect to make it
more advanced as time goes on.
- terraform state list command is introduced to list resources in a
state. This can take a series of arguments to filter this down.
Known issues, or things that aren't done in this PR on purpose:
- Unit tests for terraform state list are on the way. Unit tests for the
core changes are all there.
This means that terraform commands like `plan`, `apply`, `show`, and
`graph` will expand all modules by default.
While modules-as-black-boxes is still very true in the conceptual design
of modules, feedback on this behavior has consistently suggested that
users would prefer to see more verbose output by default.
The `-module-depth` flag and env var are retained to allow output to be
optionally limited / summarized by these commands.
Add `-target=resource` flag to core operations, allowing users to
target specific resources in their infrastructure. When `-target` is
used, the operation will only apply to that resource and its
dependencies.
The calculated dependencies are different depending on whether we're
running a normal operation or a `terraform destroy`.
Generally, "dependencies" refers to ancestors: resources falling
_before_ the target in the graph, because their changes are required to
accurately act on the target.
For destroys, "dependencies" are descendents: those resources which fall
_after_ the target. These resources depend on our target, which is going
to be destroyed, so they should also be destroyed.
Mitchell Hashimoto