This commit adds support for declaring variable types in Terraform
configuration. Historically, the type has been inferred from the default
value, defaulting to string if no default was supplied. This has caused
users to devise workarounds if they wanted to declare a map but provide
values from a .tfvars file (for example).
The new syntax adds the "type" key to variable blocks:
```
variable "i_am_a_string" {
type = "string"
}
variable "i_am_a_map" {
type = "map"
}
```
This commit does _not_ extend the type system to include bools, integers
or floats - the only two types available are maps and strings.
Validation is performed if a default value is provided in order to
ensure that the default value type matches the declared type.
In the case that a type is not declared, the old logic is used for
determining the type. This allows backwards compatiblity with previous
Terraform configuration.
Adds the `TF_SKIP_REMOTE_TESTS` env var to be used in cases where the
`http.Get()` smoke test passes but the network is not able to service
the needs of the tests.
Fixes#4421
This means that terraform commands like `plan`, `apply`, `show`, and
`graph` will expand all modules by default.
While modules-as-black-boxes is still very true in the conceptual design
of modules, feedback on this behavior has consistently suggested that
users would prefer to see more verbose output by default.
The `-module-depth` flag and env var are retained to allow output to be
optionally limited / summarized by these commands.
These new functions allow Terraform to be used for network address space
planning tasks, and make it easier to produce reusable modules that
contain or depend on network infrastructure.
For example:
- cidrsubnet allows an aws_subnet to derive its
CIDR prefix from its parent aws_vpc.
- cidrhost allows a fixed IP address for a resource to be assigned within
an address range defined elsewhere.
- cidrnetmask provides the dotted-decimal form of a prefix length that is
accepted by some systems such as routing tables and static network
interface configuration files.
The bulk of the work here is done by an external library I authored called
go-cidr. It is MIT licensed and was implemented primarily for the purpose
of using it within Terraform. It has its own unit tests and so the unit
tests within this change focus on simple success cases and on the correct
handling of the various error cases.
There isn't any precedent for abbreviating words in the interpolation
function names, and it may not be clear to all users what "enc" and "dec"
are short for, so instead we'll prefer to spell out the whole words for
improved readability.
As reported in #2782, the math operations, specifically subtraction,
can cause unexpected behavior when resource or variable names use hyphens.
I added clarification about using spaces with math operators as well as
which operations are available.
formatlist distributes formatting over lists.
See the docs for details.
As a colleague commented:
"It happens all the time that we want a set of
outputs, but in a slightly different way than
just simple joining or concatting."
formatlist (combined with join)
makes it easy to satisfy those needs.
When the `prevent_destroy` flag is set on a resource, any plan that
would destroy that resource instead returns an error. This has the
effect of preventing the resource from being unexpectedly destroyed by
Terraform until the flag is removed from the config.
Radek Simko