As of the Kilo release, styling for the OpenStack Dashboard can be altered through the use of a theme. A theme is a directory containing a _variables.scss file to override the color codes used throughout the SCSS and a _styles.scss file with additional styles to load after dashboard styles have loaded.
As of the Mitaka release, Horizon can be configured to run with multiple themes available at run time. It uses a browser cookie to allow users to toggle between the configured themes. By default, Horizon is configured with the two standard themes available: ‘default’ and ‘material’.
To configure or alter the available themes, set AVAILABLE_THEMES in local_settings.py to a list of tuples, such that ('name', 'label', 'path')
To use a custom theme, set AVAILABLE_THEMES in local_settings.py to a list of themes. If you wish to run in a mode similar to legacy Horizon, set AVAILABLE_THEMES with a single tuple, and the theme toggle will not be available at all through the application to allow user configuration themes.
For example, a configuration with multiple themes:
AVAILABLE_THEMES = [
('default', 'Default', 'themes/default'),
('material', 'Material', 'themes/material'),
]
A configuration with a single theme:
AVAILABLE_THEMES = [
('default', 'Default', 'themes/default'),
]
Both the Dashboard custom variables and Bootstrap variables can be overridden. For a full list of the Dashboard SCSS variables that can be changed, see the variables file at openstack_dashboard/static/dashboard/scss/_variables.scss.
In order to build a custom theme, both _variables.scss and _styles.scss are required and _variables.scss must provide all the default Bootstrap variables.
Custom themes must implement all of the Bootstrap variables required by Horizon in _variables.scss and _styles.scss. To make this easier, you can inherit the variables needed in the default theme and only override those that you need to customize. To inherit from the default theme, put this in your theme’s _variables.scss:
@import "/themes/default/variables";
By default, all of the themes configured by AVAILABLE_THEMES setting are collected by horizon during the collectstatic process. By default, the themes are collected into the dynamic static/themes directory, but this location can be customized via the local_settings.py variable: THEME_COLLECTION_DIR
Once collected, any theme configured via AVAILABLE_THEMES is available to inherit from by importing its variables and styles from its collection directory. The following is an example of inheriting from the material theme:
@import "/themes/material/variables";
@import "/themes/material/styles";
Horizon packages the Bootswatch SCSS files for use with its material theme. Because of this, it is simple to use an existing Bootswatch theme as a base. This is due to the fact that Bootswatch is loaded as a 3rd party static asset, and therefore is automatically collected into the static directory in /horizon/lib/. The following is an example of how to inherit from Bootswatch’s darkly theme:
@import "/horizon/lib/bootswatch/darkly/variables";
@import "/horizon/lib/bootswatch/darkly/bootswatch";
A custom theme directory can be organized differently, depending on the level of customization that is desired, as it can include static files as well as Django templates. It can include special subdirectories that will be used differently: static, templates and img.
If the theme folder contains a sub-folder called static, then that sub folder will be used as the static root of the theme. I.e., Horizon will look in that sub-folder for the _variables.scss and _styles.scss files. The contents of this folder will also be served up at /static/custom.
If the theme folder contains a sub-folder templates, then the path to that sub-folder will be prepended to the TEMPLATE_DIRS tuple to allow for theme specific template customizations.
Any Django template that is used in Horizon can be overridden through a theme. This allows highly customized user experiences to exist within the scope of different themes. Any template that is overridden must adhere to the same directory structure that the extending template expects.
For example, if you wish to customize the sidebar, Horizon expects the template to live at horizon/_sidebar.html. You would need to duplicate that directory structure under your templates directory, such that your override would live at { theme_path }/templates/horizon/_sidebar.html.
If the static root of the theme folder contains an img directory, then all images that make use of the {% themable_asset %} templatetag can be overridden.
These assets include logo.png, splash-logo.png and favicon.ico, however overriding the SVG/GIF assets used by Heat within the dashboard/img folder is not currently supported.
If you wish to customize the logo that is used on the splash screen or in the top navigation bar, then you need to create an img directory under your theme’s static root directory and place your custom logo.png or logo-splash.png within it.
If you wish to override the logo.png using the previous method, and if the image used is larger than the height of the top navigation, then the image will be constrained to fit within the height of nav. You can customize the height of the top navigation bar by customizing the SCSS variable: $navbar-height. If the image’s height is smaller than the navbar height, then the image will retain its original resolution and size, and simply be centered vertically in the available space.
Prior to the Kilo release the images files inside of Horizon needed to be replaced by your images files or the Horizon stylesheets needed to be altered to point to the location of your image.
If you need to do more to customize the logo than simply replacing the existing PNG, then you can also override the _brand.html through a custom theme. To use this technique, simply add a templates/header/_brand.html to the root of your custom theme, and add markup directly to the file. For an example of how to do this, see openstack_dashboard/themes/material/templates/header/_brand.html.
The splash / login panel can also be customized by adding templates/auth/_splash.html. See openstack_dashboard/themes/material/templates/auth/_splash.html for an example.
As of the Liberty release, Horizon has begun to conform more strictly to Bootstrap standards in an effort to embrace more responsive web design as well as alleviate the future need to re-brand new functionality for every release.
The following components, organized by release, are the only ones that make full use of the Bootstrap theme architecture.
The first step needed to create a custom branded theme for Horizon is to create a custom Bootstrap theme. There are several tools to aid in this. Some of the more useful ones include:
Note
Bootstrap uses LESS by default, but we use SCSS. All of the above tools will provide the variables.less file, which will need to be converted to _variables.scss
Pie Charts are SVG elements. SVG elements allow CSS customizations for only a basic element’s look and feel (i.e. colors, size).
Since there is no native element in Bootstrap specifically for pie charts, the look and feel of the charts are inheriting from other elements of the theme. Please see _pie_charts.scss for specifics.
Bar Charts can be either a Bootstrap Progress Bar or an SVG element. Either implementation will use the Bootstrap Progress Bar styles.
The SVG implementation will not make use of the customized Progress Bar height though, so it is recommended that Bootstrap Progress Bars are used whenever possible.
Please see _bar_charts.scss for specifics on what can be customized for SVGs. See the Progress bars section of your variables file for specific variables to customize.
The standard Django tables now make use of the native Bootstrap table markup. See Tables section of your variables file for variables to customize.
The standard Bootstrap tables will be borderless by default. If you wish to add a border, like the default theme, see openstack_dashboard/themes/default/horizon/components/_tables.scss
The login splash page now uses a standard Bootstrap panel in its implementation. See the Panels section in your variables file to variables to easily customize.
The modal login experience, as used when switching regions, uses a standard Bootstrap dialog. See the Modals section of your variables file for specific variables to customize.
The standard tabs make use of the native Bootstrap tab markup.
See Tabs section of your variables file for variables to customize.
Alerts use the basic Bootstrap brand colors. See Colors section of your variables file for specifics.
Horizon uses icon fonts to represent checkboxes. In order to customize this, you simply need to override the standard scss. For an example of this, see themes/material/static/horizon/components/_checkboxes.scss
Bootswatch is a collection of free themes for Bootstrap and is now available for use in Horizon.
In order to showcase what can be done to enhance an existing Bootstrap theme, Horizon now includes a secondary theme, roughly based on Google’s Material Design called material. Bootswatch’s Paper is a simple Bootstrap implementation of Material Design and is used by material.
Bootswatch provides a number of other themes, that once Horizon is fully theme compliant, will allow easy toggling and customizations for darker or accessibility driven experiences.
When developing a new theme for Horizon, it is required that the dynamically generated static directory be cleared after each change and the server restarted. This is not always ideal. If you wish to develop and not have to restart the server each time, it is recommended that you configure your development environment to not run in OFFLINE mode. Simply verify the following settings in your local_settings.py:
COMPRESS_OFFLINE = False
COMPRESS_ENABLED = False
The OpenStack Dashboard Site Title branding (i.e. “OpenStack Dashboard”) can be overwritten by adding the attribute SITE_BRANDING to local_settings.py with the value being the desired name.
The file local_settings.py can be found at the Horizon directory path of openstack_dashboard/local/local_settings.py.
The logo also acts as a hyperlink. The default behavior is to redirect to horizon:user_home. By adding the attribute SITE_BRANDING_LINK with the desired url target e.g., http://sample-company.com in local_settings.py, the target of the hyperlink can be changed.
If you wish to alter dashboards or panels which are not part of your codebase, you can specify a custom python module which will be loaded after the entire Horizon site has been initialized, but prior to the URLconf construction. This allows for common site-customization requirements such as:
Default Horizon panels are loaded based upon files within the openstack_dashboard/enabled/ folder. These files are loaded based upon the filename order, with space left for more files to be added. There are some example files available within this folder, with the .example suffix added. Developers and deployers should strive to use this method of customization as much as possible, and support for this is given preference over more exotic methods such as monkey patching and overrides files.
Horizon has a global overrides mechanism available to perform customizations that are not yet customizable via configuration settings. This file can perform monkey patching and other forms of customization which are not possible via the enabled folder’s customization method.
This method of customization is meant to be available for deployers of Horizon, and use of this should be avoided by Horizon plugins at all cost. Plugins needing this level of monkey patching and flexibility should instead look for changing their __init__.py file and performing customizations through other means.
To specify the python module containing your modifications, add the key customization_module to your HORIZON_CONFIG dictionary in local_settings.py. The value should be a string containing the path to your module in dotted python path notation. Example:
HORIZON_CONFIG = {
"customization_module": "my_project.overrides"
}
You can do essentially anything you like in the customization module. For example, you could change the name of a panel:
from django.utils.translation import ugettext_lazy as _
import horizon
# Rename "User Settings" to "User Options"
settings = horizon.get_dashboard("settings")
user_panel = settings.get_panel("user")
user_panel.name = _("User Options")
Or get the instances panel:
projects_dashboard = horizon.get_dashboard("project")
instances_panel = projects_dashboard.get_panel("instances")
Or just remove it entirely:
projects_dashboard.unregister(instances_panel.__class__)
You cannot unregister a default_panel. If you wish to remove a default_panel, you need to make a different panel in the dashboard as a default_panel and then unregister the former. For example, if you wished to remove the overview_panel from the Project dashboard, you could do the following:
project = horizon.get_dashboard('project')
project.default_panel = "instances"
overview = project.get_panel('overview')
project.unregister(overview.__class__)
You can also override existing methods with your own versions:
# Disable Floating IPs
from openstack_dashboard.dashboards.project.access_and_security import tabs
from openstack_dashboard.dashboards.project.instances import tables
NO = lambda *x: False
tabs.FloatingIPsTab.allowed = NO
tables.AssociateIP.allowed = NO
tables.SimpleAssociateIP.allowed = NO
tables.SimpleDisassociateIP.allowed = NO
You could also customize what columns are displayed in an existing table, by redefining the columns attribute of its Meta class. This can be achieved in 3 steps:
For example, if you wished to remove the Admin State column from the NetworksTable, you could do the following:
from openstack_dashboard.dashboards.project.networks import tables
from openstack_dashboard.dashboards.project.networks import views
class MyNetworksTable(tables.NetworksTable):
class Meta(tables.NetworksTable.Meta):
columns = ('name', 'subnets', 'shared', 'status')
views.IndexView.table_class = MyNetworksTable
If you want to add a column you can override the parent table in a similar way, add the new column definition and then use the Meta columns attribute to control the column order as needed.
Note
my_project.overrides needs to be importable by the python process running Horizon. If your module is not installed as a system-wide python package, you can either make it installable (e.g., with a setup.py) or you can adjust the python path used by your WSGI server to include its location.
Probably the easiest way is to add a python-path argument to the WSGIDaemonProcess line in Apache’s Horizon config.
Assuming your my_project module lives in /opt/python/my_project, you’d make it look like the following:
WSGIDaemonProcess [... existing options ...] python-path=/opt/python
Horizon uses font icons from Font Awesome. Please see Font Awesome for instructions on how to use icons in the code.
To add icon to Table Action, use icon property. Example:
- class CreateSnapshot(tables.LinkAction):
- name = “snapshot” verbose_name = _(“Create Snapshot”) icon = “camera”
Additionally, the site-wide default button classes can be configured by setting ACTION_CSS_CLASSES to a tuple of the classes you wish to appear on all action buttons in your local_settings.py file.
It is possible to define custom stylesheets for your dashboards. Horizon’s base template openstack_dashboard/templates/base.html defines multiple blocks that can be overridden.
To define custom css files that apply only to a specific dashboard, create a base template in your dashboard’s templates folder, which extends Horizon’s base template e.g. openstack_dashboard/dashboards/my_custom_dashboard/ templates/my_custom_dashboard/base.html.
In this template, redefine block css. (Don’t forget to include _stylesheets.html which includes all Horizon’s default stylesheets.):
{% extends 'base.html' %}
{% block css %}
{% include "_stylesheets.html" %}
{% load compress %}
{% compress css %}
<link href='{{ STATIC_URL }}my_custom_dashboard/scss/my_custom_dashboard.scss' type='text/scss' media='screen' rel='stylesheet' />
{% endcompress %}
{% endblock %}
The custom stylesheets then reside in the dashboard’s own static folder openstack_dashboard/dashboards/my_custom_dashboard/static/ my_custom_dashboard/scss/my_custom_dashboard.scss.
All dashboard’s templates have to inherit from dashboard’s base.html:
{% extends 'my_custom_dashboard/base.html' %}
...
Similarly to adding custom styling (see above), it is possible to include custom javascript files.
All Horizon’s javascript files are listed in the openstack_dashboard/ templates/horizon/_scripts.html partial template, which is included in Horizon’s base template in block js.
To add custom javascript files, create an _scripts.html partial template in your dashboard openstack_dashboard/dashboards/my_custom_dashboard/ templates/my_custom_dashboard/_scripts.html which extends horizon/_scripts.html. In this template override the block custom_js_files including your custom javascript files:
{% extends 'horizon/_scripts.html' %}
{% block custom_js_files %}
<script src='{{ STATIC_URL }}my_custom_dashboard/js/my_custom_js.js' type='text/javascript' charset='utf-8'></script>
{% endblock %}
In your dashboard’s own base template openstack_dashboard/dashboards/ my_custom_dashboard/templates/my_custom_dashboard/base.html override block js with inclusion of dashboard’s own _scripts.html:
{% block js %}
{% include "my_custom_dashboard/_scripts.html" %}
{% endblock %}
The result is a single compressed js file consisting both Horizon and dashboard’s custom scripts.
Additionally, some marketing and analytics scripts require you to place them within the page’s <head> tag. To do this, place them within the horizon/_custom_head_js.html file. Similar to the _scripts.html file mentioned above, you may link to an existing file:
<script src='{{ STATIC_URL }}/my_custom_dashboard/js/my_marketing_js.js' type='text/javascript' charset='utf-8'></script>
or you can paste your script directly in the file, being sure to use appropriate tags:
<script type="text/javascript">
//some javascript
</script>
To add custom metadata attributes to your project’s base template, include them in the horizon/_custom_meta.html file. The contents of this file will be inserted into the page’s <head> just after the default Horizon meta tags.