add api-catalog support

services/home/app/config.py

@@ -1,7 +1,16 @@
 import logging
 import os
 
+base_url = 'https://demo.pygeoapi.io'
+
 # local config, change on server for real config
 config = {
     'loglevel': int(os.getenv('ADMIN_LOG_LEVEL', logging.DEBUG))
 }
+
+services = [
+    {'href': '/master', 'title': "pygeoapi - latest GitHub 'master' version"},
+    {'href': '/stable', 'title': 'pygeoapi - latest stable version'},
+    {'href': '/cite', 'title': "pygeoapi - CITE endpoint - latest GitHub 'master' version"},  # noqa
+    {'href': '/covid-19', 'title': "pygeoapi - COVID-19 endpoint - latest GitHub 'master' version"}  # noqa
+]

services/home/app/index.py

@@ -4,12 +4,13 @@
 from datetime import datetime
 from functools import wraps, update_wrapper
 
-from config import config
+from config import base_url, config, services
 from flask import Flask, render_template, make_response, send_from_directory
 
 
 if __name__ != '__main__':
-    # When run with WSGI in Apache we need to extend the PYTHONPATH to find Python modules relative to index.py
+    # When run with WSGI in Apache we need to extend the PYTHONPATH
+    # to find Python modules relative to index.py
     sys.path.insert(0, os.path.dirname(__file__))
 
 app = Flask(__name__)
@@ -30,7 +31,7 @@ def nocache(view):
     def no_cache(*args, **kwargs):
         response = make_response(view(*args, **kwargs))
         response.headers['Last-Modified'] = datetime.now()
-        response.headers['Cache-Control'] = 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0, max-age=0'
+        response.headers['Cache-Control'] = 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0, max-age=0'  # noqa
         response.headers['Pragma'] = 'no-cache'
         response.headers['Expires'] = '-1'
         return response
@@ -45,6 +46,37 @@ def home():
     return page('home')
 
 
+# API catalog
+@app.route('/api-catalog.json')
+@app.route('/.well-known/api-catalog')
+@nocache
+def api_catalog():
+    response = {
+        'linkset': []
+    }
+
+    for service in services:
+        url = f"{base_url}{service['href']}"
+        response['linkset'].append({
+            'anchor': url,
+            'service-desc': [{
+                'href': f'{url}/openapi?f=json',
+                'title': f"{service['title']} (JSON)",
+                'type': 'application/vnd.oai.openapi+json'
+            }],
+            'service-doc': [{
+                'href': f'{url}/openapi?f=html',
+                'title': f"{service['title']} (HTML)",
+                'type': 'text/html'
+            }],
+        })
+
+    r = make_response(response)
+    r.mimetype = 'application/linkset+json'
+
+    return r
+
+
 # Specific page
 @app.route('/<string:page_name>')
 @nocache
@@ -69,12 +101,13 @@ def page(page_name):
         else:
             page_file = '%s%s' % (page_name, '.html')
 
-        result = render_template(page_file)
-    except Exception as e:
+        result = render_template(page_file, services=services)
+    except Exception:
         result = render_template('error.html'), 404
 
     return result
 
+
 if __name__ == '__main__':
     # Run as main via python index.py
     app.run(debug=True, host='0.0.0.0')

services/home/app/templates/home.html

@@ -11,21 +11,16 @@ <h2>Welcome to pygeoapi Demo Server</h2>
     <table style="width: auto;" class="table table-bordered table-condensed table-responsive">
         <thead>
         <tr>
-            <th width="50%">Demonstrations</th>
+            <th width="50%">Demonstrations (<a href="{{ url_for('api_catalog') }}" rel="api-catalog">API Catalog</a>)</th>
         </tr>
         </thead>
+
+        {% for service in services %}
         <tr>
-            <td><a target="_blank" href="/master" class="btn btn-success">pygeoapi - latest GitHub 'master' version</a></td>
-        </tr>
-        <tr>
-            <td><a target="_blank" href="/stable" class="btn btn-success">pygeoapi - latest stable version</a></td>
-        </tr>
-        <tr>
-            <td><a target="_blank" href="/cite" class="btn btn-success">pygeoapi - CITE endpoint - latest GitHub 'master' version</a></td>
-        </tr>
-        <tr>
-            <td><a target="_blank" href="/covid-19" class="btn btn-success">pygeoapi - COVID-19 endpoint - latest GitHub 'master' version</a></td>
+            <td><a target="_blank" href="{{ service['href'] }}" class="btn btn-success">{{ service['title'] }}</a></td>
         </tr>
+        {% endfor %}
+
         <tr>
             <td><a target="_blank" href="https://opengeogroep.github.io/ogc-api-features-testclient/src/index.html" class="btn btn-success">Test Client - by OpenGeoGroep</a></td>
         </tr>