Deploy an emergency banner

Last updated: 27 Jul 2023

In emergencies, GOV.UK can display important information in a banner at the top of each page of the website.

There is also a non-emergency sitewide banner, used to convey important information on GOV.UK which is not deemed emergency-level information.

GOV.UK publishes an emergency banner when there is:

a notable death
a national emergency
a local emergency

The GOV.UK Programme Team on-call (also known as the Senior Management Team escalations contact) will tell you if you need to deploy an emergency banner. This could happen outside normal office hours if you are on-call.

1. Obtain the content for the banner

The GOV.UK Programme Team on-call will give you:

the type of emergency banner: notable-death, national-emergency or local-emergency
text for the heading

They may optionally also give you:

text for the ‘short description’ (a sentence displayed under the heading)
a URL for users to find more information (a relative URL if it’s on www.gov.uk)
alternative link text for the “More information” link

Set the banner content as environment variables in your shell.

You may need to escape certain characters (including , and ") with a backslash. For example \, or \".

CAMPAIGN_CLASS="notable-death|national-emergency|local-emergency"
HEADING="replace with heading"
SHORT_DESCRIPTION="replace with description"
LINK="replace with link"
LINK_TEXT="replace with link text"

Run the Rake task, passing it the environment variables.

kubectl -n apps exec deploy/static -- rake "emergency_banner:deploy[$CAMPAIGN_CLASS,$HEADING,$SHORT_DESCRIPTION,$LINK,$LINK_TEXT]"

Most GOV.UK pages have a cache max-age of 5 minutes. After deploying the emergency banner you should expect to see the banner on all GOV.UK pages within 10 minutes.

Once the banner deployment completes:

Wait 1 minute to allow frontend application caches to expire.
Visit a page and add a cache-bust query string (a question mark followed by some random string of your choice) to the URL.
Don’t forget to change the URL to reflect the environment (staging, production) that you are checking.
Wait 10 minutes, then check that the emergency banner is visible without the cache-bust string.

You must check that:

the banner displays as expected
the header, short description and link text are correct
the link (if applicable) works
the banner is the right colour: black for notable death, red for national emergency, green for local emergency

If the banner doesn’t show, see Troubleshoot the emergency banner.

Some example pages to check

Run the emergency_banner:remove Rake task.

kubectl -n apps exec deploy/static -- rake emergency_banner:remove

Background

The information for the emergency banner is stored in a Redis key as a Ruby hash (key-value map).
A Rake task in Static sets or removes the Redis key.
Static is responsible for reading the data from Redis and rendering a partial page from a template.
Frontend rendering apps retrieve this partial page from Static via the Slimmer library, which caches the response for up to 60 seconds.

Usually this is because some cached content has not yet expired. This could be in frontend rendering apps, in Static, or in your browser.

Double-check that you are looking at the right environment.
Use a fresh private/Incognito window so that your testing is not affected by browser state such as cookies or cache.
Check whether the banner appears on www-origin (staging, production). If the banner works on origin but not on www.gov.uk, wait 5 minutes then try again.
- It is possible to flush pages from the CDN cache. This should not be necessary unless there is a bug or misconfiguration in GOV.UK.
Check the banner is present in the page template from Static (staging, production).
Inspect the Redis key to check whether the Rake task stored the banner data successfully.
Try forcing a rollout of Static, to eliminate any temporary state stored in Static.
Try clearing the frontend memcache. Log into the AWS web console for the appropriate environment, find frontend-memcached-govuk under Elasticache, Memcached clusters and press the Reboot button. The UI will ask you to confirm the request.

Inspect the Redis key

You can query Redis to check whether the banner data has been stored.

Open a Rails console for Static.

kubectl -n apps exec -it deploy/static -- rails c

Retrieve the value of the Redis key.

Redis.new.hgetall("emergency_banner")

If an emergency banner is active, the value should look similar to:

=> {"campaign_class"=>"notable-death", "heading"=>"The heading", "short_description"=>"The short description", "link"=>"https://www.gov.uk", "link_text"=>"More information about the emergency"}

If there is no banner, the value should be empty:

=> {}

Types of emergency banners

Death of a notable person

A large black banner is displayed on all GOV.UK pages, including the homepage.

The wording to use in the template will be the official title of the deceased and the years of their life, for example ‘His Royal Highness Henry VIII 1491 to 1547’. The text should link to their official biography.

GOV.UK Homepage

Other pages

National emergency (level 1 or category 2)

A large red banner is displayed on all GOV.UK pages, including the homepage.

GOV.UK Homepage

Other pages

Localised large-scale emergency (level 2 or category 1)

A large green banner is displayed on all GOV.UK pages, including the homepage.

These incidents will not be processed outside of business hours.

Deploy an emergency banner

When to deploy an emergency banner