Add gitea Downstream Host connector

Implement organisation and repository creation using the Gitea REST
API v1.  Add a 'gitea-access-token' application setting for this.

Closes #9.

2 files changed, 140 insertions, 0 deletions

diff --git a/lorrycontroller/__init__.py b/lorrycontroller/__init__.py
index ddc2f74..05c6f8a 100644
--- a/lorrycontroller/__init__.py
+++ b/lorrycontroller/__init__.py
@@ -41,6 +41,7 @@ from .static import StaticFile
 from .proxy import setup_proxy
 from . import gerrit
 from . import gitano
+from . import gitea
 from . import gitlab
 from . import local
 
@@ -48,6 +49,7 @@ from . import local
 downstream_types = {
     'gerrit': gerrit.GerritDownstream,
     'gitano': gitano.GitanoDownstream,
+    'gitea':  gitea.GiteaDownstream,
     'gitlab': gitlab.GitlabDownstream,
     'local':  local.LocalDownstream,
 }
diff --git a/lorrycontroller/gitea.py b/lorrycontroller/gitea.py
new file mode 100644
index 0000000..56aedb9
--- /dev/null
+++ b/lorrycontroller/gitea.py
@@ -0,0 +1,138 @@
+# Copyright 2020 Codethink Limited
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+import json
+import urllib.error
+import urllib.parse
+import urllib.request
+
+from . import hosts
+
+
+class _Gitea:
+    '''Run commands on a Gitea instance.'''
+
+    def __init__(self, url, token):
+        self._api_url = urllib.parse.urljoin(url, 'api/v1')
+        self._api_token = token
+
+    def request(self, method, *path, headers={}, data=None):
+        url = self._api_url
+        for part in path:
+            url = url + '/' + urllib.parse.quote(part, safe='')
+
+        headers = headers.copy()
+        headers['Authorization'] = 'token ' + self._api_token
+
+        if data is not None:
+            if method == 'GET':
+                data = urllib.parse.urlencode(data).encode('ascii')
+            elif method in ['POST', 'PATCH']:
+                data = json.dumps(data).encode('utf-8')
+                headers['Content-Type'] = 'application/json; charset=utf-8'
+            else:
+                assert isinstance(data, bytes)
+
+        request = urllib.request.Request(url, data=data, headers=headers,
+                                         method=method)
+
+        with urllib.request.urlopen(request) as response:
+            if response.getcode() == 204:
+                return None
+            return json.loads(response.read().decode('utf-8'))
+
+
+class GiteaDownstream(hosts.DownstreamHost):
+    @staticmethod
+    def add_app_settings(app_settings):
+        app_settings.string(
+            ['gitea-access-token'],
+            'access token for Gitea API access')
+
+    @staticmethod
+    def check_app_settings(app_settings):
+        app_settings.require('downstream-http-url')
+        app_settings.require('gitea-access-token')
+
+    def __init__(self, app_settings):
+        self._gitea = _Gitea(app_settings['downstream-http-url'],
+                             app_settings['gitea-access-token'])
+
+        # Gitea supports all visibilities for organisations, but
+        # repositories can only be private or inherit the visibility
+        # of the organisation.  If repository visibility is supposed
+        # to be 'internal', assume that the group will be 'internal'
+        # rather than making the repository less visible.
+        visibility = app_settings['downstream-visibility']
+        self._group_vis = 'limited' if visibility == 'internal' else visibility
+        self._repo_private = visibility == 'private'
+
+    def prepare_repo(self, repo_path, metadata):
+        path_comps = repo_path.split('/')
+
+        # As of Gitea 1.11.5, a 2-level hierarchy must be used:
+        # user/organisation and repository.  Deeper hiearchies must be
+        # collapsed using a prefixmap.
+        if len(path_comps) < 2:
+            raise ValueError(
+                'cannot create Gitea repository outside an organisation')
+        if len(path_comps) > 2:
+            raise ValueError('cannot create nested Gitea organisations')
+
+        org_name, repo_name = path_comps
+        repo_edit = {}
+
+        try:
+            repo = self._gitea.request('GET', 'repos', org_name, repo_name)
+        except urllib.error.HTTPError as e:
+            if e.code != 404:
+                raise
+
+            # Get or create organisation
+            try:
+                self._gitea.request('GET', 'orgs', org_name)
+            except urllib.error.HTTPError as e:
+                if e.code != 404:
+                    raise
+                org_data = {
+                    'username':   org_name,
+                    'visibility': self._group_vis,
+                }
+                self._gitea.request('POST', 'orgs', data=org_data)
+
+            # Create repository.  This was under /org, not /orgs,
+            # before Gitea 1.11.5 (which supports both).
+            repo_create = {
+                'auto_init': False,
+                'name':      repo_name,
+                'private':   self._repo_private,
+            }
+            repo = self._gitea.request('POST', 'org', org_name, 'repos',
+                                       data=repo_create)
+
+            # These can only be turned off after creating the repo
+            for feature in ['has_issues', 'has_wiki', 'has_pull_requests']:
+                if repo[feature] != False:
+                    repo_edit[feature] = False
+
+        # Update repository metadata
+        if 'head' in metadata and repo['default_branch'] != metadata['head']:
+            repo_edit['default_branch'] = metadata['head']
+        if 'description' in metadata \
+           and repo['description'] != metadata['description']:
+            repo_edit['description'] = metadata['description']
+        if repo_edit:
+            self._gitea.request('PATCH', 'repos', org_name, repo_name,
+                                data=repo_edit)