This new option is intended to address the previous inconsistencies where
some older subcommands supported partially changing the target directory
(where Terraform would use the new directory inconsistently) where newer
commands did not support that override at all.
Instead, now Terraform will accept a -chdir command at the start of the
command line (before the subcommand) and will interpret it as a request
to direct all actions that would normally be taken in the current working
directory into the target directory instead. This is similar to options
offered by some other similar tools, such as the -C option in "make".
The new option is only accepted at the start of the command line (before
the subcommand) as a way to reflect that it is a global command (not
specific to a particular subcommand) and that it takes effect _before_
executing the subcommand. This also means it'll be forced to appear before
any other command-specific arguments that take file paths, which hopefully
communicates that those other arguments are interpreted relative to the
overridden path.
As a measure of pragmatism for existing uses, the path.cwd object in
the Terraform language will continue to return the _original_ working
directory (ignoring -chdir), in case that is important in some exceptional
workflows. The path.root object gives the root module directory, which
will always match the overriden working directory unless the user
simultaneously uses one of the legacy directory override arguments, which
is not a pattern we intend to support in the long run.
As a first step down the deprecation path, this commit adjusts the
documentation to de-emphasize the inconsistent old command line arguments,
including specific guidance on what to use instead for the main three
workflow commands, but all of those options remain supported in the same
way as they were before. In a later commit we'll make those arguments
produce a visible deprecation warning in Terraform's output, and then
in an even later commit we'll remove them entirely so that -chdir is the
single supported way to run Terraform from a directory other than the
one containing the root module configuration.
These flags are presented as POSIX/GNU-style long-form flags
(double-dash), whereas the rest of our CLI flags as seen in sub-commands
are presented as single-dash options.
While both work in both cases (on part of the flag package allowing
double dashes as well), we converge around the single-dash form, so the
basic help text here should be consistent.
We have a copy of the output from running just "terraform" in a page on
the website. It doesn't necessarily need to be kept 100% up to date, since
users can always run the command to get the result from the horses mouth,
but it's nice to keep it somewhat up-to-date to reduce use confusion.
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.
Martin Atkins