Incidents happen and when we schedule maintenance we often face the problem of downtime. To inform our users about the ongoing maintenance to our platform, we've designed this simple maintenance page.
To redirect the user to the maintenance page, we use a set of transform- and page rules at Cloudflare to do url rewrites at the edge.
We have a transform rule that checks for https hosts in a list and gets activated when we need a redirect to the maintenance page.
(http.host in {"cloud.octopus-report.de" "octopus-reoprt.de" "www.octopus-report.de"})
The hosts in the string can be changed to the hosts that are currently under maintenance or accrue an incident.
The next step is a static rewrite to /302/maintenance. This is where our second ruleset comes in place
We have configured an always active page-rule for the domain which forwards everything matching the url *.octopus-report.de/302/maintenance to https://maintenance.octopus-report.de.
With this solution, we can decide which hosts are forwarded to the maintenance page with editing only one transform rule
We designed the html-page to be as simple as possible, this includes inline css and so on. The website is hosted at cloudflare with an automatic deployment against this git repo.