Merge branch 'make-namespaces-api-available-to-all-users' into 'master'

Make namespace API available to all users

### What does this MR do?

This MR makes it possible for a user to query namespaces to which he/she has access. Also, it adds documentation for the existing API.

### Why was this MR needed?

Even though the `groups` API exists, it might still be useful to have an endpoint that tells the namespace type (e.g. `user` vs. `group`), especially if a user has access to a number of different projects.

### What are the relevant issue numbers?

Closes https://github.com/gitlabhq/gitlabhq/issues/9328

See merge request !708

2 files changed, 45 insertions, 0 deletions

diff --git a/doc/api/README.md b/doc/api/README.md
index f6757b0a6aa..ca58c184543 100644
--- a/doc/api/README.md
+++ b/doc/api/README.md
@@ -19,6 +19,7 @@
 - [Deploy Keys](deploy_keys.md)
 - [System Hooks](system_hooks.md)
 - [Groups](groups.md)
+- [Namespaces](namespaces.md)
 
 ## Clients
 
diff --git a/doc/api/namespaces.md b/doc/api/namespaces.md
new file mode 100644
index 00000000000..7b3238441f6
--- /dev/null
+++ b/doc/api/namespaces.md
@@ -0,0 +1,44 @@
+# Namespaces
+
+## List namespaces
+
+Get a list of namespaces. (As user: my namespaces, as admin: all namespaces)
+
+```
+GET /namespaces
+```
+
+```json
+[
+  {
+    "id": 1,
+    "path": "user1",
+    "kind": "user"
+  },
+  {
+    "id": 2,
+    "path": "group1",
+    "kind": "group"
+  }
+]
+```
+
+You can search for namespaces by name or path, see below.
+
+## Search for namespace
+
+Get all namespaces that match your string in their name or path.
+
+```
+GET /namespaces?search=foobar
+```
+
+```json
+[
+  {
+    "id": 1,
+    "path": "user1",
+    "kind": "user"
+  }
+]
+```