The mapstructure library has a regrettable backward compatibility
concern whereby a WeakDecode of []interface{}{} into a target of
map[string]interface{} yields an empty map rather than an error. One
possibility is to switch to using Decode instead of WeakDecode, but this
loses the nice handling of type conversion, requiring a large volume of
code to be added to Terraform or HIL in order to retain that behaviour.
Instead we add a DecodeHook to our usage of the mapstructure library
which checks for decoding []interface{}{} or []string{} into a map and
returns an error instead.
This has the effect of defeating the code added to retain backwards
compatibility in mapstructure, giving us the correct (for our
circumstances) behaviour of Decode for empty structures and the type
conversion of WeakDecode.
The code is identical to that in the HIL library, and packaged into a
helper.
Since the data resource lifecycle contains no steps to deal with tainted
instances, we must make sure that they never get created.
Doing this out in the command layer is not the best, but this is currently
the only layer that has enough information to make this decision and so
this simple solution was preferred over a more disruptive refactoring,
under the assumption that this taint functionality eventually gets
reworked in terms of StateFilter anyway.
This allows ${data.TYPE.NAME.FIELD} interpolation syntax at the
configuration level, though since there is no special handling of them
in the core package this currently just acts as an alias for
${TYPE.NAME.FIELD}.
Previously resources were assumed to always support the full set of
create, read, update and delete operations, and Terraform's resource
management lifecycle.
Data sources introduce a new kind of resource that only supports the
"read" operation. To support this, a new "Mode" field is added to
the Resource concept within the config layer, which can be set to
ManagedResourceMode (to indicate the only mode previously possible) or
DataResourceMode (to indicate that only "read" is supported).
To support both managed and data resources in the tests, the
stringification of resources in config_string.go is adjusted slightly
to use the Id() method rather than the unusual type[name] serialization
from before, causing a simple mechanical adjustment to the loader tests'
expected result strings.
This commit adds support for native list variables and outputs, building
up on the previous change to state. Interpolation functions now return
native lists in preference to StringList.
List variables are defined like this:
variable "test" {
# This can also be inferred
type = "list"
default = ["Hello", "World"]
}
output "test_out" {
value = "${var.a_list}"
}
This results in the following state:
```
...
"outputs": {
"test_out": [
"hello",
"world"
]
},
...
```
And the result of terraform output is as follows:
```
$ terraform output
test_out = [
hello
world
]
```
Using the output name, an xargs-friendly representation is output:
```
$ terraform output test_out
hello
world
```
The output command also supports indexing into the list (with
appropriate range checking and no wrapping):
```
$ terraform output test_out 1
world
```
Along with maps, list outputs from one module may be passed as variables
into another, removing the need for the `join(",", var.list_as_string)`
and `split(",", var.list_as_string)` which was previously necessary in
Terraform configuration.
This commit also updates the tests and implementations of built-in
interpolation functions to take and return native lists where
appropriate.
A backwards compatibility note: previously the concat interpolation
function was capable of concatenating either strings or lists. The
strings use case was deprectated a long time ago but still remained.
Because we cannot return `ast.TypeAny` from an interpolation function,
this use case is no longer supported for strings - `concat` is only
capable of concatenating lists. This should not be a huge issue - the
type checker picks up incorrect parameters, and the native HIL string
concatenation - or the `join` function - can be used to replicate the
missing behaviour.
This changes the representation of maps in the interpolator from the
dotted flatmap form of a string variable named "var.variablename.key"
per map element to use native HIL maps instead.
This involves porting some of the interpolation functions in order to
keep the tests green, and adding support for map outputs.
There is one backwards incompatibility: as a result of an implementation
detail of maps, one could access an indexed map variable using the
syntax "${var.variablename.key}".
This is no longer possible - instead HIL native syntax -
"${var.variablename["key"]}" must be used. This was previously
documented, (though not heavily used) so it must be noted as a backward
compatibility issue for Terraform 0.7.
* core: Add support for marking outputs as sensitive
This commit allows an output to be marked "sensitive", in which case the
value is redacted in the post-refresh and post-apply list of outputs.
For example, the configuration:
```
variable "input" {
default = "Hello world"
}
output "notsensitive" {
value = "${var.input}"
}
output "sensitive" {
sensitive = true
value = "${var.input}"
}
```
Would result in the output:
```
terraform apply
Apply complete! Resources: 0 added, 0 changed, 0 destroyed.
Outputs:
notsensitive = Hello world
sensitive = <sensitive>
```
The `terraform output` command continues to display the value as before.
Limitations: Note that sensitivity is not tracked internally, so if the
output is interpolated in another module into a resource, the value will
be displayed. The value is still present in the state.
hil.Eval() now returns (hil.EvaluationResult, error) instead of (value,
type, error). This commit updates the call sites, but retains all
previous behaviour. Tests are also updated.
These tests demonstrates a problem where the types to a module input are
not checked. For example, if a module - inner - defines a variable
"should_be_a_map" as a map, or with a default variable of map, we do not
fail if the user sets the variable value in the outer module to a string
value. This is also a problem in nested modules.
The implementation changes add a type checking step into the graph
evaluation process to ensure invalid types are not passed.
Fixes an interpolation race that was occurring when a tainted destroy
node and a primary destroy node both tried to interpolate a computed
count in their config. Since they were sharing a pointer to the _same_
config, depending on how the race played out one of them could catch the
config uninterpolated and would then throw a syntax error.
The `Copy()` tree implemented for this fix can probably be used
elsewhere - basically we should copy the config whenever we drop nodes
into the graph - but for now I'm just applying it to the place that
fixes this bug.
Fixes#4982 - Includes a test covering that race condition.
If a variable type which is invalid (e.g. "stringg") is declared, we now
include the invalid type description in the error message to make it
easier to track down the source of the error in the source file.
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.
It seems there are 4 locations left that use the `helper/multierror`
package, where the rest is TF settled on the `hashicorp/go-multierror`
package.
Functionally this doesn’t change anything, so I suggest to delete the
builtin version as it can only cause confusion (both packages have the
same name, but are still different types according to Go’s type system.
Adds an "alias" field to the provider which allows creating multiple instances
of a provider under different names. This provides support for configurations
such as multiple AWS providers for different regions. In each resource, the
provider can be set with the "provider" field.
(thanks to Cisco Cloud for their support)
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.
James Nugent