Since we don't currently auto-install provisioner plugins this is
currently placed on the providers documentation page and referred to as
the "Provider Plugin Cache". In future this mechanism may also apply to
provisioners, in which case we'll figure out at that point where better
to place this information so it can be referenced from both the provider
and provisioner documentation pages.
This mechanism for configuring plugins is now deprecated, since it's not
capable of declaring plugin versions. Instead, we recommend just placing
plugins into a particular directory, which is now documented on the
main providers documentation page and linked from the more detailed docs
on plugins in general.
Previously we described inline here where to put the .terraformrc file,
but now we have a separate page all about this file that gives us more
room to describe in more detail where the file is placed and what else it
can do.
This function takes a map of lists of strings and inverts it so that
the string values become keys and the keys become items within the
corresponding lists.
In #15884 we adjusted the plan output to give an explicit command to run
to apply a plan, whereas before this command was just alluded to in the
prose.
Since releasing that, we've got good feedback that it's confusing to
include such instructions when Terraform is running in a workflow
automation tool, because such tools usually abstract away exactly what
commands are run and require users to take different actions to
proceed through the workflow.
To accommodate such environments while retaining helpful messages for
normal CLI usage, here we introduce a new environment variable
TF_IN_AUTOMATION which, when set to a non-empty value, is a hint to
Terraform that it isn't being run in an interactive command shell and
it should thus tone down the "next steps" messaging.
The documentation for this setting is included as part of the "...in
automation" guide since it's not generally useful in other cases. We also
intentionally disclaim comprehensive support for this since we want to
avoid creating an extreme number of "if running in automation..."
codepaths that would increase the testing matrix and hurt maintainability.
The focus is specifically on the output of the three commands we give in
the automation guide, which at present means the following two situations:
* "terraform init" does not include the final paragraphs that suggest
running "terraform plan" and tell you in what situations you might need
to re-run "terraform init".
* "terraform plan" does not include the final paragraphs that either
warn about not specifying "-out=..." or instruct to run
"terraform apply" with the generated plan file.
Previously we just assumed the reader was familiar with the idea of a
graph but didn't explain it.
Since graphs are an implementation detail of Terraform, rather than
essential information needed for new users, this revises the introduction
text to talk only about _dependencies_, which we assume the user is
familiar with as a more practical concept.
Additionally, Paul Hinze did a great talk on how Terraform uses graphs
at HashiConf 2016 which is good additional content for our existing
"Graph Internals" page, which includes a concise explanation of the
basics of graph theory.