job: import jobs from non-default namespace (#408)

* import: add helper to import namespaced resources

`nomad_job`, `nomad_csi_volume`, and `nomad_csi_volume_registration` do
not have the namespace as part of their state ID. This makes it
impossible to import them if they are registered in a non-default
namespace since only the ID is provided to the import function.

This commit adds a new helper that imports using an ID with the format
`<id>@<namespace>`. Since `@` is not a valid character for namespaces,
the last `@` character (if found) represents the separator.

* changelog: add entry for #408

* chore: add missing copyright header

* provider: fix namespaced importer

Importing namespaced resources require a namespace to be passed. Without
this requirement jobs such as `a@b` become ambiguous as it's not
possible to determine if the user intention was to import the job named
`a` from namespace `b` or job `a@b` on namespace `default`. By requiring
a namespace to be set this ambiguity is solved.

Additionally, Terraform automatically refreshes the state after an
import, so there is no need to call the `Read` method manually on
import. Doing so can also have unintended consequences, as the provider
deletes resources from state in case of a `404`, resulting in a
Terraform error when trying to import resources that don't exist.

* apply code review

CHANGELOG.md

@@ -5,8 +5,11 @@ IMPROVEMENTS:
 * provider: update Go to 1.21.5 ([#399](https://github.com/hashicorp/terraform-provider-nomad/pull/399))
 * resource/resource_acl_auth_method: add support for `token_name_format` ([#403](https://github.com/hashicorp/terraform-provider-nomad/pull/403))
 * resource/nomad_csi_volume: changes to `capacity_min` or `capacity_max` may now expand the volume instead of forcing replacement,
+* resource/nomad_csi_volume: update import key to be `<volume id>@<namespace>` to allow importing volumes from namespaces other than `default` ([#408](https://github.com/hashicorp/terraform-provider-nomad/pull/408))
+* resource/nomad_csi_volume_registration: update import key to be `<volume id>@<namespace>` to allow importing volume registrations from namespaces other than `default` ([#408](https://github.com/hashicorp/terraform-provider-nomad/pull/408))
   on Nomad version 1.6.3 or later, if the CSI plugin supports it ([#382](https://github.com/hashicorp/terraform-provider-nomad/pull/382))
 * resource/nomad_job: Add `rerun_if_dead` attribute to allow forcing a job to run again if it's marked as `dead`. ([#407](https://github.com/hashicorp/terraform-provider-nomad/pull/407))
+* resource/nomad_job: update import key to be `<job id>@<namespace>` to allow importing jobs from namespaces other than `default` ([#408](https://github.com/hashicorp/terraform-provider-nomad/pull/408))
 
 BUG FIXES:
 * resource/nomad_acl_policy: fixed a bug where the namespace would be incorrectly calculated from a job identity ([#396](https://github.com/hashicorp/terraform-provider-nomad/pull/396))

nomad/helper/import.go

@@ -0,0 +1,42 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package helper
+
+import (
+	"context"
+	"errors"
+	"strings"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+)
+
+var (
+	missingNamespaceImportErr = errors.New("missing namespace, the import ID should follow the pattern <id>@<namespace>")
+	missingIDImportErr        = errors.New("missing resource ID, the import ID should follow the pattern <id>@<namespace>")
+)
+
+// NamespacedImporterContext imports a namespaced resource that doesn't have
+// its namespace as part of the Terraform resource ID.
+func NamespacedImporterContext(_ context.Context, d *schema.ResourceData, meta any) ([]*schema.ResourceData, error) {
+	namespacedID := d.Id()
+	sepIdx := strings.LastIndex(namespacedID, "@")
+	if sepIdx == -1 {
+		return nil, missingNamespaceImportErr
+	}
+
+	ns := namespacedID[sepIdx+1:]
+	if len(ns) == 0 {
+		return nil, missingNamespaceImportErr
+	}
+
+	id := namespacedID[:sepIdx]
+	if len(id) == 0 {
+		return nil, missingIDImportErr
+	}
+
+	d.SetId(id)
+	d.Set("namespace", ns)
+
+	return []*schema.ResourceData{d}, nil
+}

nomad/resource_csi_volume.go

@@ -34,7 +34,7 @@ func resourceCSIVolume() *schema.Resource {
 		},
 
 		Importer: &schema.ResourceImporter{
-			StateContext: schema.ImportStatePassthroughContext,
+			StateContext: helper.NamespacedImporterContext,
 		},
 
 		Schema: map[string]*schema.Schema{

nomad/resource_csi_volume_registration.go

@@ -35,7 +35,7 @@ func resourceCSIVolumeRegistration() *schema.Resource {
 		},
 
 		Importer: &schema.ResourceImporter{
-			StateContext: schema.ImportStatePassthroughContext,
+			StateContext: helper.NamespacedImporterContext,
 		},
 
 		Schema: map[string]*schema.Schema{

nomad/resource_job.go

@@ -19,6 +19,7 @@ import (
 	"github.com/hashicorp/nomad/jobspec2"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+	"github.com/hashicorp/terraform-provider-nomad/nomad/helper"
 )
 
 func resourceJob() *schema.Resource {
@@ -36,7 +37,7 @@ func resourceJob() *schema.Resource {
 		},
 
 		Importer: &schema.ResourceImporter{
-			StateContext: schema.ImportStatePassthroughContext,
+			StateContext: helper.NamespacedImporterContext,
 		},
 
 		Schema: map[string]*schema.Schema{

website/docs/r/csi_volume.html.markdown

@@ -137,5 +137,22 @@ configuration options.
 - `create` `(string: "10m")` - Timeout when creating or updating a new CSI volume.
 - `delete` `(string: "10m")` - Timeout when deleting a CSI volume.
 
+## Importing CSI Volumes
+
+CSI volumes are imported using the pattern `<volume ID>@<namespace>` .
+
+```console
+$ terraform import nomad_csi_volume.mysql mysql@my-namespace
+nomad_csi_volume.mysql: Importing from ID "mysql@my-namespace"...
+nomad_csi_volume.mysql: Import prepared!
+  Prepared nomad_csi_volume for import
+nomad_csi_volume.mysql: Refreshing state... [id=mysql@my-namespace]
+
+Import successful!
+
+The resources that were imported are shown above. These resources are now in
+your Terraform state and will henceforth be managed by Terraform.
+```
+
 [tf_docs_timeouts]: https://www.terraform.io/docs/configuration/blocks/resources/syntax.html#operation-timeouts
 [tf_docs_prevent_destroy]: https://developer.hashicorp.com/terraform/language/meta-arguments/lifecycle#prevent_destroy

website/docs/r/csi_volume_registration.html.markdown

@@ -130,4 +130,22 @@ can be referenced:
 - `create` `(string: "10m")` - Timeout when registering a new CSI volume.
 - `delete` `(string: "10m")` - Timeout when deregistering a CSI volume.
 
+## Importing CSI Volume Registrations
+
+CSI volume registrations are imported using the pattern
+`<volume ID>@<namespace>`.
+
+```console
+$ terraform import nomad_csi_volume.mysql mysql@my-namespace
+nomad_csi_volume_registration.mysql: Importing from ID "mysql@my-namespace"...
+nomad_csi_volume_registration.mysql: Import prepared!
+  Prepared nomad_csi_volume_registration for import
+nomad_csi_volume_registration.mysql: Refreshing state... [id=mysql@my-namespace]
+
+Import successful!
+
+The resources that were imported are shown above. These resources are now in
+your Terraform state and will henceforth be managed by Terraform.
+```
+
 [tf_docs_timeouts]: https://www.terraform.io/docs/configuration/blocks/resources/syntax.html#operation-timeouts

website/docs/r/job.html.markdown

@@ -300,6 +300,23 @@ options when [`detach`](#detach) is set to `false`:
 - `create` `(string: "5m")` - Timeout when registering a new job.
 - `update` `(string: "5m")` - Timeout when updating an existing job.
 
+## Importing Jobs
+
+Jobs are imported using the pattern `<job ID>@<namespace>`.
+
+```console
+$ terraform import nomad_job.example example@my-namespace
+nomad_job.example: Importing from ID "example@my-namespace"...
+nomad_job.example: Import prepared!
+  Prepared nomad_job for import
+nomad_job.example: Refreshing state... [id=example@my-namespace]
+
+Import successful!
+
+The resources that were imported are shown above. These resources are now in
+your Terraform state and will henceforth be managed by Terraform.
+```
+
 [tf_docs_timeouts]: https://www.terraform.io/docs/configuration/blocks/resources/syntax.html#operation-timeouts
 [tf_docs_templatefile]: https://www.terraform.io/docs/configuration/functions/templatefile.html
 [tf_docs_string_template]: https://www.terraform.io/language/expressions/strings#string-templates