feat: support specifying client_id on oauth2 client creation (#128)

Allow users to specify a custom `client_id` when creating an OAuth2
client resource, matching the Ory API capability. The field is
Optional+Computed with RequiresReplace, so changing it forces recreation.

Closes #121

Author: KT-Doan

docs/resources/oauth2_client.md

@@ -15,6 +15,21 @@ OAuth2 clients are used for machine-to-machine authentication or user-facing OAu
 
 ~> **Important:** The `client_secret` is only returned when the client is first created. Store it securely immediately after creation. It cannot be retrieved later, including after `terraform import`.
 
+## Custom Client ID
+
+By default, a random `client_id` is generated when the client is created. You can specify a custom `client_id` for consistency across environments:
+
+```hcl
+resource "ory_oauth2_client" "api" {
+  client_id   = "my-api-client"
+  client_name = "API Client"
+  grant_types = ["client_credentials"]
+  scope       = "read write"
+}
+```
+
+~> **Note:** Changing the `client_id` after creation forces the resource to be destroyed and recreated. The `client_id` must be unique within the project.
+
 ## Example Usage
 
 ```terraform
@@ -141,6 +156,14 @@ resource "ory_oauth2_client" "cli_tool" {
   scope                      = "openid offline_access"
 }
 
+# Client with a custom client_id (useful for consistency across environments)
+resource "ory_oauth2_client" "custom_id" {
+  client_id   = "my-api-client"
+  client_name = "API Client with Custom ID"
+  grant_types = ["client_credentials"]
+  scope       = "api:read api:write"
+}
+
 # Same-apply: Create project and OAuth2 client together
 # Use resource-level credentials when the project doesn't exist yet
 resource "ory_oauth2_client" "same_apply" {
@@ -329,6 +352,7 @@ terraform import ory_oauth2_client.api <client-id>
 - `backchannel_logout_session_required` (Boolean) Whether the client requires a session identifier in back-channel logout notifications.
 - `backchannel_logout_uri` (String) OpenID Connect back-channel logout URI.
 - `client_credentials_grant_access_token_lifespan` (String) Access token lifespan for client credentials grant (e.g., '1h', '30m').
+- `client_id` (String) The OAuth2 client ID. If not specified, a random ID will be generated. Once set, changing this value forces recreation of the resource.
 - `client_uri` (String) URL of the client's homepage.
 - `contacts` (List of String) List of contact email addresses for the client maintainers.
 - `device_authorization_grant_access_token_lifespan` (String) Access token lifespan for device authorization grant (e.g., '1h').
@@ -364,6 +388,5 @@ terraform import ory_oauth2_client.api <client-id>
 
 ### Read-Only
 
-- `client_id` (String) The OAuth2 client ID.
 - `client_secret` (String, Sensitive) The OAuth2 client secret. Only returned on creation.
 - `id` (String) Internal Terraform ID (same as client_id).

examples/resources/ory_oauth2_client/resource.tf

@@ -121,6 +121,14 @@ resource "ory_oauth2_client" "cli_tool" {
   scope                      = "openid offline_access"
 }
 
+# Client with a custom client_id (useful for consistency across environments)
+resource "ory_oauth2_client" "custom_id" {
+  client_id   = "my-api-client"
+  client_name = "API Client with Custom ID"
+  grant_types = ["client_credentials"]
+  scope       = "api:read api:write"
+}
+
 # Same-apply: Create project and OAuth2 client together
 # Use resource-level credentials when the project doesn't exist yet
 resource "ory_oauth2_client" "same_apply" {

internal/resources/oauth2client/resource.go

@@ -115,6 +115,14 @@ resource "ory_oauth2_client" "api" {
   token_endpoint_auth_method  = "client_secret_post"
 }
 
+# With a custom client_id
+resource "ory_oauth2_client" "custom" {
+  client_id                   = "my-api-client"
+  client_name                 = "API Client with Custom ID"
+  grant_types                 = ["client_credentials"]
+  scope                       = "read write"
+}
+
 output "client_id" {
   value = ory_oauth2_client.api.client_id
 }
@@ -149,10 +157,12 @@ func (r *OAuth2ClientResource) Schema(ctx context.Context, req resource.SchemaRe
 				},
 			},
 			"client_id": schema.StringAttribute{
-				Description: "The OAuth2 client ID.",
+				Description: "The OAuth2 client ID. If not specified, a random ID will be generated. Once set, changing this value forces recreation of the resource.",
+				Optional:    true,
 				Computed:    true,
 				PlanModifiers: []planmodifier.String{
 					stringplanmodifier.UseStateForUnknown(),
+					stringplanmodifier.RequiresReplace(),
 				},
 			},
 			"client_secret": schema.StringAttribute{
@@ -407,6 +417,10 @@ func (r *OAuth2ClientResource) Create(ctx context.Context, req resource.CreateRe
 		Scope:      ory.PtrString(plan.Scope.ValueString()),
 	}
 
+	if !plan.ClientID.IsNull() && !plan.ClientID.IsUnknown() {
+		oauthClient.ClientId = ory.PtrString(plan.ClientID.ValueString())
+	}
+
 	if !plan.GrantTypes.IsNull() && !plan.GrantTypes.IsUnknown() {
 		var grantTypes []string
 		resp.Diagnostics.Append(plan.GrantTypes.ElementsAs(ctx, &grantTypes, false)...)

internal/resources/oauth2client/resource_test.go

@@ -3,7 +3,9 @@
 package oauth2client_test
 
 import (
+	"fmt"
 	"testing"
+	"time"
 
 	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
 
@@ -227,6 +229,51 @@ func TestAccOAuth2ClientResource_withResourceCredentials(t *testing.T) {
 	})
 }
 
+func TestAccOAuth2ClientResource_withCustomClientID(t *testing.T) {
+	clientID := fmt.Sprintf("tf-acc-test-%d", time.Now().UnixNano())
+
+	acctest.RunTest(t, resource.TestCase{
+		PreCheck:                 func() { acctest.AccPreCheck(t) },
+		ProtoV6ProviderFactories: acctest.TestAccProtoV6ProviderFactories(),
+		Steps: []resource.TestStep{
+			// Create with custom client_id
+			{
+				Config: acctest.LoadTestConfig(t, "testdata/with_custom_client_id.tf.tmpl", map[string]string{
+					"Name":     "Test Client Custom ID",
+					"ClientID": clientID,
+				}),
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckResourceAttr("ory_oauth2_client.test", "client_id", clientID),
+					resource.TestCheckResourceAttr("ory_oauth2_client.test", "id", clientID),
+					resource.TestCheckResourceAttr("ory_oauth2_client.test", "client_name", "Test Client Custom ID"),
+					resource.TestCheckResourceAttr("ory_oauth2_client.test", "scope", "api:read"),
+					resource.TestCheckResourceAttrSet("ory_oauth2_client.test", "client_secret"),
+				),
+			},
+			// ImportState
+			{
+				ResourceName:            "ory_oauth2_client.test",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"client_secret"},
+			},
+			// Update (change name/scope, client_id stays the same)
+			{
+				Config: acctest.LoadTestConfig(t, "testdata/with_custom_client_id_updated.tf.tmpl", map[string]string{
+					"Name":     "Test Client Custom ID Updated",
+					"ClientID": clientID,
+				}),
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckResourceAttr("ory_oauth2_client.test", "client_id", clientID),
+					resource.TestCheckResourceAttr("ory_oauth2_client.test", "id", clientID),
+					resource.TestCheckResourceAttr("ory_oauth2_client.test", "client_name", "Test Client Custom ID Updated"),
+					resource.TestCheckResourceAttr("ory_oauth2_client.test", "scope", "api:read api:write"),
+				),
+			},
+		},
+	})
+}
+
 func TestAccOAuth2ClientResource_withTokenLifespans(t *testing.T) {
 	acctest.RunTest(t, resource.TestCase{
 		PreCheck:                 func() { acctest.AccPreCheck(t) },

internal/resources/oauth2client/testdata/with_custom_client_id.tf.tmpl

@@ -0,0 +1,8 @@
+resource "ory_oauth2_client" "test" {
+  client_id   = "[[ .ClientID ]]"
+  client_name = "[[ .Name ]]"
+
+  grant_types    = ["client_credentials"]
+  response_types = ["token"]
+  scope          = "api:read"
+}

internal/resources/oauth2client/testdata/with_custom_client_id_updated.tf.tmpl

@@ -0,0 +1,8 @@
+resource "ory_oauth2_client" "test" {
+  client_id   = "[[ .ClientID ]]"
+  client_name = "[[ .Name ]]"
+
+  grant_types    = ["client_credentials"]
+  response_types = ["token"]
+  scope          = "api:read api:write"
+}

templates/resources/oauth2_client.md.tmpl

@@ -15,6 +15,21 @@ OAuth2 clients are used for machine-to-machine authentication or user-facing OAu
 
 ~> **Important:** The `client_secret` is only returned when the client is first created. Store it securely immediately after creation. It cannot be retrieved later, including after `terraform import`.
 
+## Custom Client ID
+
+By default, a random `client_id` is generated when the client is created. You can specify a custom `client_id` for consistency across environments:
+
+```hcl
+resource "ory_oauth2_client" "api" {
+  client_id   = "my-api-client"
+  client_name = "API Client"
+  grant_types = ["client_credentials"]
+  scope       = "read write"
+}
+```
+
+~> **Note:** Changing the `client_id` after creation forces the resource to be destroyed and recreated. The `client_id` must be unique within the project.
+
 ## Example Usage
 
 {{ tffile "examples/resources/ory_oauth2_client/resource.tf" }}