Double stack size on gitea

Git can segfault and cause a gitea error due to the size of the
openstack/openstack repo.  Give it more stack space.

The hard limit is a workaround for
https://github.com/moby/moby/issues/39125

Change-Id: Ibce79d8ab27af3070bf9c5f584d0d78f2b266388

playbooks/roles/gitea/templates/docker-compose.yaml.j2

@@ -23,6 +23,10 @@ services:
     environment:
       - USER_UID=1000
       - USER_GID=1000
+    ulimits:
+      stack:
+        soft: 16777216
+        hard: 9223372036854775807
     volumes:
       - /var/gitea/data:/data
       - /var/gitea/conf:/custom/conf

testinfra/test_gitea.py

@@ -23,3 +23,9 @@ def test_gitea_listening(host):
     assert gitea_http.is_listening
     gitea_ssh = host.socket("tcp://0.0.0.0:222")
     assert gitea_ssh.is_listening
+
+def test_ulimit(host):
+    cmd = host.run("docker exec giteadocker_gitea-web_1 prlimit")
+    expected = ("STACK      max stack size                      "
+                "16777216 9223372036854775807 bytes")
+    assert expected in cmd.stdout.split('\n')