In 3ea1592 the plan rendering was refactored to add an extra indirection
of producing a display-oriented plan object first and then rendering from
that object.
There was a logic error while adapting the existing plan rendering code
to use the new display-oriented object: the core InstanceDiff object sets
the "Destroy" flag (a boolean) for both DiffDestroy and DiffDestroyCreate,
and so this code previously checked r.Destroy to recognize the
"destroy-create" case. This was incorrectly adapted to a check for the
display action being DiffDestroy, when it should actually have been
DiffDestroyCreate.
The effect of this bug was to cause the "(forces new resource)"
annotations to not be displayed on attributes, though the resource-level
information still correctly reflected that a new resource was required.
This fix restores the attribute-level annotations.
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.
Add an ImportStateIdFunc field to the ImportState testing functionality.
This will allow for more powerful generation of complex import state IDs
that can't be accomplished by ImportStateId or ImportStateIdPrefix
themselves.
The previous diff presentation was rather "wordy", and not very friendly
to those who can't see color either because they have color-blindness or
because they don't have a color-supporting terminal.
This new presentation uses the actual symbols used in the plan output
and tries to be more concise. It also uses some framing characters to
try to separate the different stages of "terraform plan" to make it
easier to visually navigate.
The apply command also adopts this new plan presentation, in preparation
for "terraform apply" (with interactive plan confirmation) becoming the
primary, safe workflow in the next major release.
Finally, we standardize on the terminology "perform" and "actions" rather
than "execute" and "changes" to reflect the fact that reading is now an
action and that isn't actually a _change_.
The fact that we clean up data source state by applying a "destroy" action
for them is an implementation detail, and so should not be visible to
outside callers or to the user.
Signalling these as real destroys creates confusion for users because
they see Terraform say things like:
data.template_file.foo: Refreshing state..."
...which, to an understandably-nervous sysadmin, might make them suspect
that the underlying object was deleted, rather than just Terraform's
record of it.
Martin Atkins