Add landing page with configuration (#219)

JIRA: RHELWF-10318

greenwave/api_v1.py

@@ -21,6 +21,54 @@
 log = logging.getLogger(__name__)
 
 
+@api.route('/', methods=['GET'])
+def landing_page():
+    """
+    Landing page with links to documentation and other APIs and interpretation
+    of outcomes from ResultDB results (passed, error and incomplete).
+
+    **Sample response**:
+
+    .. sourcecode:: none
+
+       HTTP/1.1 200 OK
+       Connection: close
+       Content-Length: 452
+       Content-Type: application/json
+       Date: Tue, 05 Dec 2023 07:45:39 GMT
+       Server: Werkzeug/3.0.1 Python/3.12.0
+
+       {
+           "api_v1": "http://greenwave.example.com/api/v1.0",
+           "documentation": "https://gating-greenwave.readthedocs.io",
+           "koji_api": "https://koji.example.com/kojihub",
+           "outcomes_error": ["ERROR"],
+           "outcomes_incomplete": ["QUEUED", "RUNNING"],
+           "outcomes_passed": ["PASSED", "INFO"],
+           "remote_rule_policies": {
+               "*": "https://git.example.com/{pkg_namespace}{pkg_name}/raw/{rev}/gating.yaml",
+               "brew-build-group": "https://git.example.com/side-tags/{pkg_namespace}{pkg_name}.yaml"
+           },
+           "resultsdb_api": "https://resultsdb.example.com/api/v2.0",
+           "waiverdb_api": "http://waiverdb.example.com/api/v1.0"
+       }
+    """  # noqa: E501
+    return (
+        jsonify({
+            "documentation": current_app.config["DOCUMENTATION_URL"],
+            "api_v1": current_app.config["GREENWAVE_API_URL"],
+            "resultsdb_api": current_app.config["RESULTSDB_API_URL"],
+            "waiverdb_api": current_app.config["WAIVERDB_API_URL"],
+            "koji_api": current_app.config["KOJI_BASE_URL"],
+            "outcomes_passed": current_app.config["OUTCOMES_PASSED"],
+            "outcomes_error": current_app.config["OUTCOMES_ERROR"],
+            "outcomes_incomplete": current_app.config["OUTCOMES_INCOMPLETE"],
+            "remote_rule_policies": current_app.config["REMOTE_RULE_POLICIES"],
+        }),
+        200,
+    )
+
+
 @api.route('/version', methods=['GET'])
 def version():
     """

greenwave/app_factory.py

@@ -4,7 +4,7 @@
 import logging.config
 
 from flask import Flask
-from greenwave.api_v1 import api
+from greenwave.api_v1 import api, landing_page
 from greenwave.utils import json_error, load_config, mangle_key
 from greenwave.policies import load_policies
 from greenwave.subjects.subject_type import load_subject_types
@@ -50,6 +50,7 @@ def create_app(config_obj=None):
 
     # register blueprints
     app.register_blueprint(api, url_prefix="/api/v1.0")
+    app.add_url_rule('/', view_func=landing_page)
     app.add_url_rule('/healthcheck', view_func=healthcheck)
 
     # Initialize the cache.

greenwave/config.py

@@ -94,6 +94,8 @@ class Config(object):
     SESSION_COOKIE_SECURE = True
     SESSION_COOKIE_SAMESITE = "Lax"
 
+    DOCUMENTATION_URL = "https://gating-greenwave.readthedocs.io"
+
 
 class ProductionConfig(Config):
     DEBUG = False

greenwave/tests/test_landing_page.py

@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: GPL-2.0+
+from pytest import mark
+
+
+@mark.parametrize("endpoint", ("/", "/api/v1.0/"))
+def test_landing_page(client, endpoint):
+    response = client.get(endpoint)
+    assert response.status_code == 200, response.text
+    data = response.json
+    config = client.application.config
+    assert data == {
+        "documentation": config["DOCUMENTATION_URL"],
+        "api_v1": config["GREENWAVE_API_URL"],
+        "resultsdb_api": config["RESULTSDB_API_URL"],
+        "waiverdb_api": config["WAIVERDB_API_URL"],
+        "koji_api": config["KOJI_BASE_URL"],
+        "outcomes_passed": list(config["OUTCOMES_PASSED"]),
+        "outcomes_error": list(config["OUTCOMES_ERROR"]),
+        "outcomes_incomplete": list(config["OUTCOMES_INCOMPLETE"]),
+        "remote_rule_policies": config["REMOTE_RULE_POLICIES"],
+    }