'localhost', does not match expected hostname with basic Caddy reverse proxy

Barnaby Keene

I've managed to get Jira up on my server now, it's a vanilla installation straight from the install docs running on port 8990 and connected to a postgres db on localhost.

My reverse proxy is Caddy, it simply redirects http://jira.mydomain to http://localhost:8990 (no SSL, that looks like a nightmare to set up, one of the reasons I use Caddy is the automated SSL - but I won't bother with that right now).

I first got the baseurl error which I fixed. Now I'm getting this other error which seems like its trying to use localhost for every reletive address.

The dashboard shows the `UrlHostnameMismatchException` but I've tried to set the hostname URL via server.xml:

<Engine name="Catalina" defaultHost="jira.mydomain">
    <Host name="jira.mydomain" appBase="webapps" unpackWARs="true" autoDeploy="true">
        <Context path="" docBase="${catalina.home}/atlassian-jira" reloadable="false" useHttpOnly="true">

Restarted and still the same error. How on earth do I fix this? Do I have to modify the Caddy config to do something or change the Jira config?

I'd rather not install another proxy just for Atlassian apps, Caddy does a great job for my existing services and the painless HTTPS support is great.

Barnaby Keene

I figured it out straight after, but maybe this will be useful. If you're a Caddy reverse-proxy user and you stumbled upon this, I hope it helps!

The solution is to add a `proxyName` and `proxyPort` attribute to the `<Connector>` object:

<Connector port="8990"
    maxThreads="150"
    minSpareThreads="25"
    connectionTimeout="20000"

    proxyName="jira.mydomain"
    proxyPort="80"

Annoyingly, this information was buried in Apache specific documentation whereas it's software-agnostic when it comes to reverse proxy applications.

I'm now going to try HTTPS with Caddy's auto-installed certs and update this response...