add api docs for positions

docs/openapi.yaml

@@ -361,6 +361,69 @@ paths:
                 {"status": "completed", "result": {"removed_from_groups": ["group2","group3"], "unsubscribed_from_lists": ["list1","list2"]}}
         "404":
           $ref: "#/components/responses/GroupNotFoundErrorResponse"
+  /positions:
+    get:
+      tags: ['positions']
+      summary: Show current positions
+      description: >-
+        Shows the list of positions and members holding them.
+      responses:
+        "200":
+          description: Success
+          content:
+            application/json:
+              schema:
+                type: object
+                additionalProperties:
+                  type: string
+                example:
+                  president: user0
+                  vice-president: user1
+                  sysadmin: user2
+                  treasurer:
+    post:
+      tags: ['positions']
+      summary: Update positions
+      description: >-
+        Update members for each positions. Members not specified in the parameters will be removed
+        from the position and unsubscribed from the exec's mailing list. New position holders will
+        be subscribed to the mailing list.
+      requestBody:
+        description: New position holders
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              additionalProperties:
+                type: string
+              example:
+                president: user0
+                vice-president: user1
+                sysadmin: user2
+                treasurer:
+      responses:
+        "200":
+          description: Success
+          content:
+            text/plain:
+              schema:
+                type: string
+                description: Streaming response
+              example: |
+                {"status": "in progress", "operation": "update_positions_ldap"}
+                {"status": "in progress", "operation": "update_exec_group_ldap"}
+                {"status": "in progress", "operation": "subscribe_to_mailing_list"}
+                {"status": "completed", "result": "OK"}
+        "400":
+          description: Failed
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  error:
+                    type: string
   /mailman/{mailing_list}/{username}:
     post:
       tags: ['mailman']