There are a few situations that we've seen arise quite commonly for folks
upgrading from Terraform 0.11 to 0.12. These particular problems are not
things that Terraform 0.12 can fix automatically during upgrading, but
we can at least give some better feedback to users that they ought to be
addressed _before_ upgrading.
The provider address problem is already detected and flagged by the
"terraform 0.11checklist" command that folks should run as part of their
upgrade process, but the module address problem is not something we
noticed was lacking validation in 0.11 and so the checklist tool doesn't
cover it. Due to the lack of coverage in the checklist tool, this commit
also includes an additional section in the upgrade guide that mentions
the problem and gives instructions on how to address it.
I've seen folks ask about how to express this in resource address syntax
a number of times now, so adding this example here to illustrate how it
looks when there are multiple levels of module to traverse through.
This is redundant with other information further up the page, but having
it as an entirely separate example gives an opportunity to include more
introductory text to explain what the example is showing.
There are some differences between the Terraform CLI and Terraform Cloud ideas of workspaces.
This documentation aims to explain those differences and show different patterns for configuring the remote backend and the implications of different approaches.
As mentioned in #17871 the current example can hide the fact that the module
path plays an important role. The example's explanation is expanded.
Moreover, the verb "attach" is replaced with "map" to make the vocabulary
consistent with the wording in the documentation of the terraform state.
A very common question since we launched the two repetition constructs
is how to deal with situations where the input data structure doesn't
match one-to-one with the desired configuration.
This adds some full worked examples of two common situations that have
come up in questions. To avoid adding a lot of extra content to the
already-large "expressions" and "resources" pages, the main bulk of this
new content lives with the relevant functions themselves as a full example
of one thing they are good for, and then we'll link to them from the two
general documentation sections where folks are likely to be reading when
they encounter the problem.
