Add health check endpoint

Endpoint '/v1/health/ping' provides info about service status

* OSBS-6692

Signed-off-by: Martin Bašti <mbasti@redhat.com>

README.md

@@ -306,6 +306,71 @@ curl \
    -X DELETE https://example.com/v1/myorg/myrepo/1.1.5
 ```
 
+### Health status
+
+Check status of OMPS service and accessibility of:
+* quay service
+* koji service
+
+If HTTP status is not 200, consider service as not working.
+
+#### Endpoints
+
+* [GET] `/v1/health/ping`
+
+
+#### Replies
+
+**OK**
+
+HTTP code: 200
+
+```json
+{
+  "ok": true,
+  "services": {
+    "koji": {
+      "details": "It works!",
+      "ok": true
+    },
+    "quay": {
+      "details": "It works!",
+      "ok": true
+    }
+  },
+  "status": 200
+}
+```
+
+**Failure**
+
+HTTP code: other than 200
+
+Format of message cannot be guaranteed. However service will try to answer with
+the same format as is listed above, for example:
+
+```json
+{
+  "ok": false,
+  "services": {
+    "koji": {
+      "details": "Cannot connect!",
+      "ok": false
+    },
+    "quay": {
+      "details": "It works!",
+      "ok": true
+    }
+  },
+  "status": 503
+}
+```
+
+
+#### Examples
+```bash
+curl https://example.com/v1/health/ping
+```
 
 ## Development
 

omps/api/v1/__init__.py

@@ -7,4 +7,4 @@
 
 API = Blueprint('v1', __name__)
 
-from . import packages, push  # noqa, register routes
+from . import packages, push, health  # noqa, register routes

omps/api/v1/health.py

@@ -0,0 +1,79 @@
+#
+# Copyright (C) 2019 Red Hat, Inc
+# see the LICENSE file for license
+#
+
+import logging
+
+from flask import jsonify
+import requests
+from requests.exceptions import RequestException
+
+from . import API
+from omps.errors import KojiError
+from omps.quay import get_cnr_api_version
+from omps.koji_util import KOJI
+
+logger = logging.getLogger(__name__)
+
+
+@API.route("/health/ping", methods=('GET', ))
+def ping():
+    """Provides status report
+     * 200 if everything is ok
+     * 503 if service is not working as expected
+    :return: HTTP Response
+    """
+    def _ok():
+        return {
+            "ok": True,
+            "details": "It works!",
+        }
+
+    def _err(exc):
+        return {
+            "ok": False,
+            "details": str(exc)
+        }
+
+    everything_ok = True
+
+    # quay.io status
+    try:
+        # try to retrieve API version to check if quay.io is alive
+        get_cnr_api_version()
+    except RequestException as e:
+        logger.error('Koji version check: %s', e)
+        quay_result = _err(e)
+        everything_ok = False
+    else:
+        quay_result = _ok()
+
+    # koji status
+    try:
+        # try to retrieve API version to check if koji is alive
+        KOJI.get_api_version()
+    except KojiError as e:
+        logger.error('Quay version check: %s', e)
+        koji_result = _err(e)
+        everything_ok = False
+    else:
+        koji_result = _ok()
+
+    status_code = (
+        requests.codes.ok if everything_ok
+        else requests.codes.unavailable
+    )
+
+    data = {
+        "ok": everything_ok,
+        "status": status_code,
+        "services": {
+            "koji": koji_result,
+            "quay": quay_result
+        }
+    }
+
+    resp = jsonify(data)
+    resp.status_code = status_code
+    return resp

omps/koji_util.py

@@ -83,5 +83,18 @@ def download_manifest_archive(self, nvr, target_fd):
         url = self._kojiroot_url + path
         self._file_download(url, target_fd)
 
+    def get_api_version(self):
+        """Returns API version of koji
+
+        :rtype: int
+        :return: Koji API version
+        """
+        try:
+            ver = self.session.getAPIVersion()
+        except Exception as e:
+            raise KojiError(str(e))
+
+        return ver
+
 
 KOJI = KojiUtil()

omps/quay.py

@@ -395,4 +395,17 @@ def publish_repo(self, repo):
             raise QuayPackageError(msg)
 
 
+def get_cnr_api_version():
+    """Returns quay's CNR api version
+
+    :raises: HTTPError if version cannot be fetched
+    :rtype: str
+    :returns: API version
+    """
+    url = "https://quay.io/cnr/version"
+    r = requests.get(url)
+    r.raise_for_status()
+    return r.json()['cnr-api']
+
+
 ORG_MANAGER = OrgManager()

tests/api/v1/test_api_health.py

@@ -0,0 +1,92 @@
+#
+# Copyright (C) 2019 Red Hat, Inc
+# see the LICENSE file for license
+#
+
+import requests
+import requests_mock
+
+from omps.errors import KojiError
+
+
+PING_ENDPOINT = '/v1/health/ping'
+
+
+def test_health_ping(client, mocked_koji_get_api_version, mocked_quay_version):
+    """Test reporting of ok status"""
+    rv = client.get(PING_ENDPOINT)
+
+    expected = {
+        "ok": True,
+        "status": requests.codes.ok,
+        "services": {
+            "koji": {
+                "ok": True,
+                "details": "It works!"
+            },
+            "quay": {
+                "ok": True,
+                "details": "It works!"
+            },
+        }
+    }
+
+    assert rv.status_code == requests.codes.ok
+    assert rv.get_json() == expected
+
+
+def test_health_ping_broken_quay(client, mocked_koji_get_api_version):
+    """Test if broken quay is reported properly"""
+    with requests_mock.Mocker() as m:
+        m.get(
+            'https://quay.io/cnr/version',
+            status_code=requests.codes.server_error
+        )
+        rv = client.get(PING_ENDPOINT)
+
+    expected = {
+        "ok": False,
+        "status": requests.codes.unavailable,
+        "services": {
+            "koji": {
+                "ok": True,
+                "details": "It works!"
+            },
+            "quay": {
+                "ok": False,
+                "details": (
+                    "500 Server Error: None for url: "
+                    "https://quay.io/cnr/version"
+                )
+            },
+        }
+    }
+    assert rv.status_code == requests.codes.unavailable
+    assert rv.get_json() == expected
+
+
+def test_health_ping_broken_koji(
+    client, mocked_quay_version, mocked_koji_get_api_version
+):
+    """Test if broken koji is reported properly"""
+    e_msg = "something happened"
+    mocked_koji_get_api_version.side_effect = KojiError(e_msg)
+
+    rv = client.get(PING_ENDPOINT)
+
+    expected = {
+        "ok": False,
+        "status": requests.codes.unavailable,
+        "services": {
+            "koji": {
+                "ok": False,
+                "details": e_msg
+            },
+            "quay": {
+                "ok": True,
+                "details": "It works!"
+            },
+        }
+    }
+    assert rv.status_code == requests.codes.unavailable
+    assert rv.get_json() == expected

tests/conftest.py

@@ -6,6 +6,7 @@
 import re
 import os
 import shutil
+from unittest.mock import Mock
 import zipfile
 
 from flexmock import flexmock
@@ -121,6 +122,21 @@ def fake_download(nvr, target_fd):
         KOJI.download_manifest_archive = orig
 
 
+@pytest.fixture
+def mocked_koji_get_api_version():
+    """Mock global KOJI.get_api_version to return valid version"""
+    def fake_version():
+        return 1
+
+    orig = KOJI.get_api_version
+    try:
+        m = Mock(return_value=1)
+        KOJI.get_api_version = m
+        yield m
+    finally:
+        KOJI.get_api_version = orig
+
+
 @pytest.fixture
 def mocked_koji():
     """Return mocked KojiUtil with session"""
@@ -129,3 +145,11 @@ def mocked_koji():
     ku.initialize(conf)
     ku._session = flexmock()
     return ku
+
+
+@pytest.fixture
+def mocked_quay_version():
+    """Return mocked quay api version"""
+    with requests_mock.Mocker() as m:
+        m.get("/cnr/version", json={"cnr-api": "0.0.1-test"})
+        yield m

tests/test_koji_util.py

@@ -106,3 +106,24 @@ def test_download_manifest_archive(self, mocked_koji):
                 mocked_koji.download_manifest_archive('test', target_f)
                 target_f.seek(0)
                 assert target_f.read() == data
+
+    def test_get_api_version(self, mocked_koji):
+        """Test get_api_version method"""
+
+        version = 1
+        mocked_koji.session.should_receive('getAPIVersion').and_return(version)
+
+        assert mocked_koji.get_api_version() == version
+
+    def test_get_api_version_error(self, mocked_koji):
+        """Test if get_api_version method raises proper exception"""
+        msg = "something wrong happened"
+        (mocked_koji.session
+         .should_receive('getAPIVersion')
+         .and_raise(Exception(msg))
+         )
+
+        with pytest.raises(KojiError) as ke:
+            mocked_koji.get_api_version()
+
+        assert msg in str(ke)

tests/test_quay.py

@@ -14,7 +14,12 @@
     QuayPackageError,
     QuayPackageNotFound,
 )
-from omps.quay import QuayOrganization, ReleaseVersion, OrgManager
+from omps.quay import (
+    get_cnr_api_version,
+    QuayOrganization,
+    OrgManager,
+    ReleaseVersion,
+)
 from omps.settings import Config
 
 
@@ -360,3 +365,8 @@ class ConfClass:
         assert isinstance(unconfigured_org, QuayOrganization)
         assert not unconfigured_org.public
         assert not unconfigured_org.oauth_access
+
+
+def test_get_cnr_api_version(mocked_quay_version):
+    """Tests of quay.get_cnr_api_version function"""
+    assert get_cnr_api_version() == "0.0.1-test"