core: remove default flow background from default css, set static in base_full and dynamically in if/flow

closes #1056

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

authentik/core/templates/if/flow.html

@@ -11,6 +11,11 @@
 
 {% block head %}
 <script src="{% static 'dist/FlowInterface.js' %}?v={{ ak_version }}" type="module"></script>
+<style>
+.pf-c-background-image::before {
+    background-image: url("{{ flow.background_url }}");
+}
+</style>
 {% endblock %}
 
 {% block body %}

authentik/core/templates/login/base_full.html

@@ -7,6 +7,14 @@
 <link rel="stylesheet" type="text/css" href="{% static 'dist/patternfly.min.css' %}?v={{ ak_version }}">
 {% endblock %}
 
+{% block head %}
+<style>
+.pf-c-background-image::before {
+    background-image: url("/static/dist/assets/images/flow_background.jpg");
+}
+</style>
+{% endblock %}
+
 {% block body %}
 <div class="pf-c-background-image">
     <svg xmlns="http://www.w3.org/2000/svg" class="pf-c-background-image__filter" width="0" height="0">

web/src/authentik.css

@@ -68,7 +68,7 @@ html > form > input {
 
 /* ensure background on non-flow pages match */
 .pf-c-background-image::before {
-    background-image: var(--ak-flow-background, url("/static/dist/assets/images/flow_background.jpg"));
+    background-image: var(--ak-flow-background);
     background-position: center;
 }