feat(coder-attach): add coder_external_agent resource (#424)

* add coder_external_agent resource

* Change token to agent_id

Author: kacpersaw

docs/resources/external_agent.md

@@ -0,0 +1,24 @@
+---
+# generated by https://github.com/hashicorp/terraform-plugin-docs
+page_title: "coder_external_agent Resource - terraform-provider-coder"
+subcategory: ""
+description: |-
+  Define an external agent to be used in a workspace.
+---
+
+# coder_external_agent (Resource)
+
+Define an external agent to be used in a workspace.
+
+
+
+<!-- schema generated by tfplugindocs -->
+## Schema
+
+### Required
+
+- `agent_id` (String) The `id` property of a `coder_agent` resource to associate with.
+
+### Read-Only
+
+- `id` (String) The ID of this resource.

provider/external_agent.go

@@ -0,0 +1,31 @@
+package provider
+
+import (
+	"context"
+
+	"github.com/google/uuid"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/diag"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+)
+
+func externalAgentResource() *schema.Resource {
+	return &schema.Resource{
+		SchemaVersion: 1,
+
+		Description: "Define an external agent to be used in a workspace.",
+		CreateContext: func(ctx context.Context, rd *schema.ResourceData, _ interface{}) diag.Diagnostics {
+			rd.SetId(uuid.NewString())
+			return nil
+		},
+		ReadContext:   schema.NoopContext,
+		DeleteContext: schema.NoopContext,
+		Schema: map[string]*schema.Schema{
+			"agent_id": {
+				Type:        schema.TypeString,
+				Description: "The `id` property of a `coder_agent` resource to associate with.",
+				ForceNew:    true,
+				Required:    true,
+			},
+		},
+	}
+}

provider/external_agent_test.go

@@ -0,0 +1,49 @@
+package provider_test
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/terraform"
+	"github.com/stretchr/testify/require"
+)
+
+func TestExternalAgent(t *testing.T) {
+	t.Parallel()
+
+	t.Run("OK", func(t *testing.T) {
+		t.Parallel()
+
+		resource.Test(t, resource.TestCase{
+			ProviderFactories: coderFactory(),
+			IsUnitTest:        true,
+			Steps: []resource.TestStep{{
+				Config: `
+				provider "coder" {
+				}
+
+				resource "coder_agent" "dev" {
+					os = "linux"
+					arch = "amd64"
+				}
+				
+				resource "coder_external_agent" "dev" {
+					agent_id = coder_agent.dev.id
+				}
+				`,
+				Check: func(state *terraform.State) error {
+					require.Len(t, state.Modules, 1)
+					require.Len(t, state.Modules[0].Resources, 2)
+
+					agentResource := state.Modules[0].Resources["coder_agent.dev"]
+					require.NotNil(t, agentResource)
+					externalAgentResource := state.Modules[0].Resources["coder_external_agent.dev"]
+					require.NotNil(t, externalAgentResource)
+
+					require.Equal(t, agentResource.Primary.Attributes["id"], externalAgentResource.Primary.Attributes["agent_id"])
+					return nil
+				},
+			}},
+		})
+	})
+}

provider/provider.go

@@ -74,6 +74,7 @@ func New() *schema.Provider {
 			"coder_script":         scriptResource(),
 			"coder_env":            envResource(),
 			"coder_devcontainer":   devcontainerResource(),
+			"coder_external_agent": externalAgentResource(),
 		},
 	}
 }