'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 · Accepted solution]

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...

[Barnaby Keene]

SSL with Caddy's auto-install was simpler than I thought!

Just add the `scheme` field alongside `proxyName`, set `proxyPort` to 443 and modify your Caddyfile to use https.

    ...
    proxyName="jira.mydomain"
    proxyPort="433"
    scheme="https"

[Lars Olav Velle]

You might also want to add:

secure="true"

[Barnaby Keene]

Oh yeah I forgot to mention, I was looking for documentation on that attribute but couldn't find any. What does it actually mean?

[Andrew Barton]

Just to provide additional clarity, the modifications referenced are for the tomcat server.xml. 

This answer helped me, but required slight modifications based on this thread (as I am running docker instance):

https://community.atlassian.com/t5/Jira-questions/How-to-use-a-custom-server-xml-on-Jira-Docker-image/qaq-p/1166929

If you are also using Docker, this folder location should be persisted:

https://community.atlassian.com/t5/Jira-Software-questions/How-to-run-jira-software-docker-with-HTTPS/qaq-p/1148354

Thanks for your prompt response.  After reading instructions, I am putting both directory in volumes 

 volumes:    

- jira-home-data:/var/atlassian/application-data/jira    

- jira-app-data:/opt/atlassian/etc/