The "terraform init" command has a lot of different functionality now,
making it hard to follow all of the options in the previous presentation.
Instead, here we describe each of the steps and its associated options
separately, hopefully making it easier to understand what each option
relates to.
In addition, much of the detail around backend partial configuration is
factored out into the backend configuration page, where it seems more
"at home"; previously it felt hard to follow exactly how partial
configuration would be used, due to the information on it being split over
two different pages.
This is documented for all other Hashicorp products using this service but
was missed for Terraform. This serves as a disclosure of the fact that
Terraform reaches out to a Hashicorp service, an explanation of the
purpose of that request, and instructions on how to disable it in
environments where it is inappropriate or cannot be supported due to a
firewall or other connectivity restrictions.
A common reason to want to use `terraform plan` is to have a chance to
review and confirm a plan before running it. If in fact that is the
only reason you are running plan, this new `terraform apply -auto-approve=false`
flag provides an easier alternative to
P=$(mktemp -t plan)
terraform refresh
terraform plan -refresh=false -out=$P
terraform apply $P
rm $P
The flag defaults to true for now, but in a future version of Terraform it will
default to false.
Previously the behavior for -target when given a module address was to
target only resources directly within that module, ignoring any resources
defined in child modules.
This behavior turned out to be counter-intuitive, since users expected
the -target address to be interpreted hierarchically.
We'll now use the new "Contains" function for addresses, which provides
a hierarchical "containment" concept that is more consistent with user
expectations. In particular, it allows module.foo to match
module.foo.module.bar.aws_instance.baz, where before that would not have
been true.
Since Contains isn't commutative (unlike Equals) this requires some
special handling for targeting specific indices. When given an argument
like -target=aws_instance.foo[0], the initial graph construction (for
both plan and refresh) is for the resource nodes from configuration, which
have not yet been expanded to separate indexed instances. Thus we need
to do the first pass of TargetsTransformer in mode where indices are
ignored, with the work then completed by the DynamicExpand method which
re-applies the TargetsTransformer in index-sensitive mode.
This is a breaking change for anyone depending on the previous behavior
of -target, since it will now select more resources than before. There is
no way provided to obtain the previous behavior. Eventually we may support
negative targeting, which could then combine with positive targets to
regain the previous behavior as an explicit choice.
Martin Atkins