How can I create a subdomain for a Cloudflare tunnel ?
reddit / selfhosted

----------------------------------------------------------------------
LeVraiRoiDHyrule · 2023-12-24 01:44

Hi,

I recently began my journey into Cloudflare Tunnel. I've set my tunnel
to point on a subdomain server2.example.com because I already have a
server on example.com. Now I want to host multiple services, all
pointing to server2.example.com.

When I host Home Assistant on server2.example.com, it works. But now
if I create CNAME homeassistant.example.com pointing to
server2.example.com, it doesn't work.

I suspect it might be because of HTTP Host Header. I have set them as
server2.example.com in my Tunnel settings. But I have no idea how to
make it work.

Could someone help me on this ? Have a great day.

----------------------------------------------------------------------
ericesev · 2023-12-24 02:05

Remove that HTTP host header feature in the tunnel settings. Then try
using the CNAME. I think that should work.

----------------------------------------------------------------------
LeVraiRoiDHyrule · 2023-12-24 10:49

It doesn't work, address is unreachable. And with that setting
removed, hosting on server2.website.com no longer works either, this
time with a cloudflare bad gateway error.

----------------------------------------------------------------------
MadeWithPat · 2023-12-24 13:29

Do you have DNS records that point at your tunnel? You’ll have to
manually create a wildcard record if you want to go that route.
Alternatively, go to the configure screen for the tunnel and add
subdomains in the ‘public hostname’ tab - this will create DNS entries
for you (for non-wildcard hostnames), just make sure they point at
Caddy.

----------------------------------------------------------------------
MadeWithPat · 2023-12-24 13:39

What do the public hostnames look like in the tunnel config? You
probably want to delete your CNAME and add homeassistant.example.com
to the tunnel’s public hostnames instead (pointed at Caddy) -
cloudflare will create the relevant DNS record. Adding a wildcard
hostname to the tunnel config instead might also work

----------------------------------------------------------------------
LeVraiRoiDHyrule · 2023-12-24 14:00

That's it !!!! I deleted my CNAME and added that subdomain in the
public hostname tunnel settings instead, and it worked ! I also had to
make the TLS Origin Server Name match the subdomain, and with HTTP
Host Header left empty. And it works ! My plan at first was to make
only one public hostname with CNAMEs pointing at it but this seems to
work so I think I'll go with it. Is one solution better than the other
in terms of security or practicality ?

----------------------------------------------------------------------
MadeWithPat · 2023-12-24 14:06

I imagine it’s 6 / half a dozen in terms of security. Personally I
would just go this route - sometimes you’ll want to stand up a service
and keep it local so you can get through the first time setup screens,
then you could come back in and add it to the tunnel after it’s ready
to use. I currently just have a wildcard set on the tunnel and DNS so
exposing happens automatically whenever my proxy finds it (using
traefik), but sounds like that might not work if you’re already using
the domain elsewhere.