In earlier versions of Terraform the result of terraform state show was
in the pre-0.12 "flatmap" structure that was unable to reflect nested
data structures. That was fixed in Terraform 0.12, but as a consequence
this statement about the output being machine-parseable (which was
debateable even in older versions) is incorrect.
Fortunately, we now have "terraform show -json" to get output that is
intentionally machine-parseable, so we'll recommend to use that instead
here. The JSON output of that command is a superset of what's produced by
"terraform state show", so should be usable to meet any use-case that
might previously have been met by parsing the "terraform state show"
output.
We have released the v0.12-oriented content to the website early in order
to support the beta process, but in some places we neglected to explicitly
mark features or content as being v0.12-only.
Here we add explicit markers to the main cases we've seen where readers
have reported confusion, along with some other tweaks in similar vein.
Martin Atkins