Keycloak themes

[verhulstm]

How do i change the look for the keycloak login page?

[viniciusdc]

Hey @verhulstm, we've just included this ability in the latest release 2025.3.1. You need to include this section in your config:

security:
  keycloak:
    initial_root_password: ***
    themes:
      enabled: true
      repository: https://github.com/****/keycloak-custom-theme
      branch: master

We don't have yet a template for the theme, its on the works, but you can achieve it following this:

• Create a public github repo, containing a folder with the name to your theme (e.g demo);
• Inside such folder copy over the contents from keycloak/keycloak@main/themes/src/main/resources-community/theme/base or use my-cool-theme-name example from keycloak/keycloak-quickstarts@latest/extension/extend-admin-console.
• In your nebari-config.yaml, make sure to correctly pass the URL for your github repo under the repository and branch fields.
• After deploying, go to the Keycloak UI and select your new theme

[viniciusdc]

Hey @verhulstm, that will not work since that command is not available in the keycloak container, and that might not persist depending on how keycloak stores the theme. Does using the yaml fields from above not fit your use case?

[verhulstm]

i want to be able to fully automate the deployment without manual steps in the keycloak admin

[viniciusdc]

I see; in that case, the above snippet should address that since it auto-installs the theme under the .../themes folder of the Keycloak's pod. The only minimal interaction would be to enable it from the Keycloak Admin Console UI after redeployment:

[viniciusdc]

I think the only way to change an already available theme (following the steps from above) in keycloak without going through the UI, would be to use PUT /admin/realms/{realm} with the keycloak API (or use the respective python client, you can see some examples in Nebari source code itself) to update the realm settings with the theme:

...
loginTheme: "",
accountTheme: "",
adminTheme: "",
emailTheme: ""
...

[viniciusdc]

@verhulstm Just to give you a more concrete example of the above, here's a simple python function that would allow you to change the theme programmatically:

from _nebari.keycloak import get_keycloak_admin_from_config

def update_realm_theme(config_filename, new_theme):
    """
    Updates the login theme for a given Keycloak realm.

	:param config_filename: the absolute path of you current nebari config yaml file;
	:param new_theme: name of the available theme installed on keycloak that you plan on switching to;
    """

    # Initialize the KeycloakAdmin client using the admin credentials from Nebari's config file
    keycloak_admin = get_keycloak_admin_from_config(config_filename)

    # Fetch the current representation of the target realm
    realm_representation = keycloak_admin.get_realm('nebari')

    # Update the login theme field in the realm representation
    realm_representation["loginTheme"] = new_theme
    
    # Save the changes back to Keycloak
    keycloak_admin.update_realm(realm_representation)
    
    print(f"Successfully updated realm '{target_realm}' to use theme '{new_theme}'.")