Override templates in a custom directory

This commit allows the override and the addition of templates using a custom directory that will be added to the loader. See the `TEMPLATES_CUSTOM_DIRECTORIES` configuration value in the example configuration file. Signed-off-by: Aurélien Bompard <aurelien@bompard.org>
fedora-infra · Jul 21, 2021 · 855eee4 · 855eee4
1 parent 31c3b89
commit 855eee4
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Showing 6 changed files with 68 additions and 2 deletions.
diff --git a/news/PR701.feature b/news/PR701.feature
@@ -0,0 +1 @@
+Allow template override with a custom directory, see the ``TEMPLATES_CUSTOM_DIRECTORIES`` configration value
diff --git a/noggin.cfg.example b/noggin.cfg.example
@@ -87,6 +87,21 @@ MAIL_SUPPRESS_SEND = True
 # will only be accessible to users that have this role.
 # STAGE_USERS_ROLE = "Stage User Managers"
 
+# Additional directories to look up folders in. The templates in these directories
+# will override the app's template with the same filename. You can also create the
+# following templates to insert HTML in the output:
+# - `after-navbar.html`: will be inserted between the navbar and the main content
+#   on every page
+# - `before-footer.html`: will be inserted between the main content and the footer
+#   on every page
+# - `head.html`: will be inserted at the end of the <head> tag on every page
+# TEMPLATES_CUSTOM_DIRECTORIES = []
+
+# The following sources will be added to the Content Security Policy for images.
+# This can be useful if you want to add images in custom templates.
+# https://content-security-policy.com/img-src/
+# ACCEPT_IMAGES_FROM = []
+
 # Spam checking
 # BASSET_URL = None
 # SPAMCHECK_TOKEN_EXPIRATION = 60  # in minutes

diff --git a/noggin/app.py b/noggin/app.py
@@ -2,6 +2,7 @@
 from logging.config import dictConfig
 
 import flask_talisman
+import jinja2
 from flask import Flask
 from flask_healthz import healthz
 from flask_mail import Mail
@@ -55,6 +56,15 @@ def create_app(config=None):
     if app.config.get("TEMPLATES_AUTO_RELOAD"):
         app.jinja_env.auto_reload = True
 
+    # Custom template folders
+    if app.config["TEMPLATES_CUSTOM_DIRECTORIES"]:
+        app.jinja_loader = jinja2.ChoiceLoader(
+            [
+                jinja2.FileSystemLoader(app.config["TEMPLATES_CUSTOM_DIRECTORIES"]),
+                app.jinja_loader,
+            ]
+        )
+
     # Logging
     if app.config.get("LOGGING"):
         dictConfig(app.config["LOGGING"])
@@ -83,9 +93,13 @@ def create_app(config=None):
                 # https://csp.withgoogle.com/docs/strict-csp.html#example
                 "'strict-dynamic'",
             ],
-            "img-src": ["'self'", "seccdn.libravatar.org"],
+            "img-src": ["'self'", "seccdn.libravatar.org"]
+            + app.config["ACCEPT_IMAGES_FROM"],
+            # The style-src directive needs to be specified (even if it's the same as default-src)
+            # to add the nonce.
+            "style-src": "'self'",
         },
-        content_security_policy_nonce_in=['script-src'],
+        content_security_policy_nonce_in=['script-src', 'style-src'],
     )
 
     # Template filters

diff --git a/noggin/defaults.py b/noggin/defaults.py
@@ -36,6 +36,9 @@
 
 STAGE_USERS_ROLE = "Stage User Managers"
 
+TEMPLATES_CUSTOM_DIRECTORIES = []
+ACCEPT_IMAGES_FROM = []
+
 BASSET_URL = None
 SPAMCHECK_TOKEN_EXPIRATION = 60  # in minutes
 

diff --git a/noggin/templates/base.html b/noggin/templates/base.html
@@ -8,10 +8,13 @@
     <link href="{{ url_for('static', filename='fonts/font-awesome.css') }}" rel="stylesheet" />
     <link href="{{ url_for('static', filename='css/main.css') }}" rel="stylesheet" type="text/css">
     <title>{% block title %}{% endblock %}{% if self.title() %} - {% endif %}{% block website %}noggin{% endblock %}</title>
+    {% include "head.html" ignore missing %}
   </head>
   <body>
     {% block navbar %} {% endblock %}
+    {% include "after-navbar.html" ignore missing %}
     {% block bodycontent %}{% endblock %}
+    {% include "before-footer.html" ignore missing %}
     {% block footer %}{% endblock %}
     {% block scripts %}
       {% if current_user %}

diff --git a/noggin/tests/unit/test_app.py b/noggin/tests/unit/test_app.py
@@ -36,3 +36,33 @@ def test_logging(mocker, app_config):
     logging_config = mocker.patch("noggin.app.dictConfig")
     create_app(config)
     logging_config.assert_called_once_with("dummy-logging-config")
+
+
+def test_templates_custom_directory_insertion(app_config, tmp_path):
+    tpl_dir = tmp_path / "templates"
+    os.makedirs(tpl_dir)
+    config = app_config.copy()
+    config["TEMPLATES_CUSTOM_DIRECTORIES"] = [tpl_dir]
+    app = create_app(config)
+    # Use the template placeholder
+    with open(tpl_dir / "after-navbar.html", "w") as tpl:
+        tpl.write("TESTING TEMPLATES CUSTOM DIR\n")
+    with app.test_client() as client:
+        response = client.get('/')
+        assert response.status_code == 200
+        assert "TESTING TEMPLATES CUSTOM DIR" in response.get_data(as_text=True)
+
+
+def test_templates_custom_directory_override(app_config, tmp_path):
+    tpl_dir = tmp_path / "templates"
+    os.makedirs(tpl_dir)
+    config = app_config.copy()
+    config["TEMPLATES_CUSTOM_DIRECTORIES"] = [tpl_dir]
+    app = create_app(config)
+    # Override the whole page template
+    with open(tpl_dir / "index.html", "w") as tpl:
+        tpl.write("TESTING TEMPLATES CUSTOM DIR\n")
+    with app.test_client() as client:
+        response = client.get('/')
+        assert response.status_code == 200
+        assert response.get_data(as_text=True) == "TESTING TEMPLATES CUSTOM DIR"