docs: Pass `-target` arguments in a custom workflow

[dimisjim]

Hey there.

I am trying to run a custom workflow which intends to have atlantis push the DEBUG log of the terraform process run to an external provider (by redirecting its outputto a file and in another step, to upload that log file to the desired source)

Current issue is that I can't find a way to both have terraform run via a plan: steps: run: way (which is needed in order to perform the output redireciton to that file) AND at the same time pass the target arguments given in the PR comment.

I have tried using the COMMENT_ARGS env var, but I haven't found a way so far to make it work consistently, regardless of the amount of target args given in the comment PR.

Is there any standard way of doing this? There doesn't seem to be a clearly described way to do this in https://www.runatlantis.io/docs/custom-workflows.html#reference

Thanks

EDIT:
Most of my attempts lead to stat: no such file or directory errors:

- run: terraform$ATLANTIS_TERRAFORM_VERSION plan -input=false -refresh -no-color -out \"$PLANFILE\" ${COMMENT_ARGS//'\'/"\\\\"}

exit status 1: running "terraform$ATLANTIS_TERRAFORM_VERSION plan -input=false -refresh -no-color -out \\\"$PLANFILE\\\" ${COMMENT_ARGS//'\\'/\"\\\\\\\\\"}" in "/home/atlantis/.atlantis/repos/1plusX/infrastructure/860/default/terraform": 
stat \\-\\t\\a\\r\\g\\e\\t\\=\\m\\o\\d\\u\\l\\e\\.\\b\\a\\s\\t\\i\\o\\n\\-\\m\\o\\n\\i\\t\\o\\r\\i\\n\\g\\-\\l\\a\\m\\b\\d\\a: no such file or directory

[DevAndrewGeorge]

Over a year later, but I wound up having to deal with this. My solution was by adding another workflow step to export the TF_CLI_ARGS env var:

- env:
    name: TF_CLI_ARGS
    command: echo $COMMENT_ARGS | tr ',' ' ' | sed -r 's/\\(.)/\1/g'

[nitrocode]

@DevAndrewGeorge please add the documentation to the website with the use case. We'd really appreciate it

[3bbbeau]

Over a year later, but I wound up having to deal with this. My solution was by adding another workflow step to export the TF_CLI_ARGS env var:

- env:
    name: TF_CLI_ARGS
    command: echo $COMMENT_ARGS | tr ',' ' ' | sed -r 's/\\(.)/\1/g'

Many thanks for this solution!

Just a note for readers: if you run other terraform/terragrunt commands in your custom workflow in addition to plan within the same step, ensure to name the environment variable TF_CLI_ARGS_plan otherwise you'll get an error when using -target along unsupported commands (e.g. terraform show):

Expand

Error: Failed to parse command-line flags

flag provided but not defined: -target

[jukie]

In a run statement couldn't you do "${COMMENT_ARGS//\\/}"?