Merge pull request #175 from projectsyn/feat/discovery

Add discovery URL that returns metadata about lieutenant

docs/modules/ROOT/pages/references/configuration.adoc

@@ -22,6 +22,16 @@ This value will be set as fact on new clusters.
 |Namespace where the Kubernetes objects are stored.
 |`default`
 
+|OIDC_DISCOVERY_URL
+|The OpenID Connect discovery endpoint of the identity provider when using OIDC.
+It's returned on the discovery URI and will be picked up by Commodore
+|Empty
+
+|OIDC_CLIENT_ID
+|The client id used to authenticate when using OIDC.
+It's returned on the discovery URI and will be picked up by Commodore
+|Empty
+
 |K8S_AUTH_CLIENT_CACHE_SIZE
 |For each new API client (identified by the auth token), a Kubernetes client will be instantiated to pass through the request with the same token, which usually takes 2 seconds.
 The K8s client instance will be cached for subsequent API calls and this setting controls how many instances to keep in memory.

main.go

@@ -18,7 +18,14 @@ var (
 )
 
 func main() {
-	e, err := service.NewAPIServer()
+	conf := service.APIConfig{
+		APIVersion:       Version,
+		Namespace:        os.Getenv("NAMESPACE"),
+		OidcDiscoveryURL: os.Getenv("OIDC_DISCOVERY_URL"),
+		OidcCLientID:     os.Getenv("OIDC_CLIENT_ID"),
+	}
+
+	e, err := service.NewAPIServer(conf)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, err.Error()+"\n")
 		os.Exit(1)

openapi.yaml

@@ -34,6 +34,26 @@ components:
         A unique object identifier string. Automatically generated by the API on creation (in the form
         "<letter>-<adjective>-<noun>-<digits>" where all letters are lowercase, max 63 characters in total).
       readOnly: true
+    OIDCConfig:
+      type: object
+      required:
+        - discoveryUrl
+        - clientId
+      properties:
+        discoveryUrl:
+          type: string
+          format: uri-template
+        clientId:
+          type: string
+    Metadata:
+      type: object
+      required:
+        - apiVersion
+      properties:
+        apiVersion:
+          type: string
+        oidc:
+          $ref: '#/components/schemas/OIDCConfig'
     TenantProperties:
       type: object
       description: |-
@@ -244,6 +264,23 @@ tags:
   - name: system
     description: API system
 paths:
+  /:
+    get:
+      operationId: discovery
+      summary: Lieutenant API Root
+      description: Get metadata about Lieutenant
+      security: []
+      tags:
+        - system
+      responses:
+        '200':
+          description: Lieutenant metadata
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Metadata'
+        default:
+          $ref: '#/components/responses/Default'
   /tenants:
     get:
       operationId: listTenants