The SDK has a mechanism that effectively makes it possible to declare an
attribute as being _conditionally_ required, which is not a concept that
Terraform Core is aware of.
Since this mechanism is in practice only used for a small UX improvement
in prompting for these values interactively when the environment variable
is not set, we avoid here introducing all of this complexity into the
plugin protocol by just having the provider selectively modify its schema
if it detects that such an attribute might be set dynamically.
This then prevents Terraform Core from validating the presence of the
argument or prompting for a new value for it, allowing the null value to
pass through into the provider so that the default value can be generated
again dynamically.
This is a kinda-kludgey solution which we're accepting here because the
alternative would be a much-more-complex two-pass decode operation within
Core itself, and that doesn't seem worth it.
This fixes#19139.
The main significant change here is that the package name for the proto
definition is "tfplugin5", which is important because this name is part
of the wire protocol for references to types defined in our package.
Along with that, we also move the generated package into "internal" to
make it explicit that importing the generated Go package from elsewhere is
not the right approach for externally-implemented SDKs, which should
instead vendor the proto definition they are using and generate their
own stubs to ensure that the wire protocol is the only hard dependency
between Terraform Core and plugins.
After this is merged, any provider binaries built against our
helper/schema package will need to be rebuilt so that they use the new
"tfplugin5" package name instead of "proto".
In a future commit we will include more elaborate and organized
documentation on how an external codebase might make use of our RPC
interface definition to implement an SDK, but the primary concern here
is to ensure we have the right wire package name before release.
In order to prevent mismatched states between read/plan/apply, we need
to ensure that the attributes are generated consistently each time.
Because of the various ways in which helper/schema and the hcl2 shims
interpret empty values, the only way to ensure consistency is to always
remove them altogether.
This makes sure the diff is generated with the matching set ids from
helper/schema.
Update the tests to add ID fields to the state, which will exists in
practice, since any state traversing through the shims will have the ID
inserted.
helper/schema will remove "timeouts" from the config, and stash them in
the diff.Meta map. Terraform sees "timeouts" as a regular config block,
so needs them to be present in the state in order to not show a diff.
Have the GRPCProviderServer shim copy all timeout values into any state
it returns to provide consistent diffs in core.
Resource timeouts were a separate config block, but did not exist in the
resource schema. Insert any defined timeouts when generating the
configshema.Block so that the fields can be accepted and validated by
core.
`Any()` allows any single passing validation of multiple `SchemaValidateFunc` to pass validation to cover cases where a standard validation function does not cover the functionality or to make error messaging simpler.
Example provider usage:
```go
ValidateFunc: validation.Any(
validation.IntAtLeast(42),
validation.IntAtMost(5),
),
```
`All()` combines the outputs of multiple `SchemaValidateFunc`, to reduce the usage of custom validation functions that implement standard validation functions.
Example provider usage:
```go
ValidateFunc: validation.All(
StringLenBetween(5, 42),
StringMatch(regexp.MustCompile(`[a-zA-Z0-9]+`), "value must be alphanumeric"),
),
```
`IntInSlice()` is the `int` equivalent of `StringInSlice()`
Example provider usage:
```go
ValidateFunc: validation.IntInSlice([]int{30, 60, 120})
```
Output from unit testing:
```
$ make test TEST=./helper/validation
==> Checking that code complies with gofmt requirements...
go generate ./...
2018/10/17 14:16:03 Generated command/internal_plugin_list.go
go list ./helper/validation | xargs -t -n4 go test -timeout=2m -parallel=4
go test -timeout=2m -parallel=4 github.com/hashicorp/terraform/helper/validation
ok github.com/hashicorp/terraform/helper/validation 1.106s
```
The helper/resource unit tests will panic, because they were using the
legacy terraform.MockResourceProvider, which doesn't have the same
internals required by the new GRPC shims.
Fail these tests for now, and a new test provider will need to be made
out of a schema.Provider instance.
Use the new SimpleDiff method of the provider so that the diff isn't
altered by ForceNew attributes.
Always set an "id" as RequiresReplace so core knows an instance will be
replaced, even if all ForceNew attributes are filtered out due to
ignore_changes.
Terraform now handles any actual "diffing" of resource, and the existing
Diff functions are only used to shim the schema.Provider to the new
methods. Since terraform is handling what used to be the Diff, the
provider now should not modify the diff based on RequiresNew due to it
interfering with the ignore_changes handling.
While the schema Diff fucntion returns a nil diff when creating an empty
(except for id) resource, the Apply function expects the diff to be
initialized and ampty.
PlanResourceChange isn't returning the diff, but rather it is returning
the destired state. If the propsed state results in a nil diff, then,
the propsed state is what should be returned.
Make sure Meta fields are not nil, as the schema package expects those
to be initialised.
An earlier change introduced a new function testConfig to the main code
for this package, which conflicted with a function of the same name in
the test code.
Here we rename the function from the test code, allowing for the more
generally-named testConfig to be the one in the main code.
The "id" field is assumed to always exist, and must have a valid value.
Set "id" to unknown when planning new resource changes to indicate that
it will be computed.
Martin Atkins