tl;dr: this was a temporary issue solved by a later commit, if you checked out discourse after 28 Oct but before 4 Nov, git pull to update
Having installed a production Discourse forum, I wanted to get a local dev instance up and running for testing.
There are good instructions for doing just that using Docker. Don’t do what I did: follow the production install method and assume that will work by pointing the prod hostname at it in /etc/hosts.
Unfortunately, when I followed the instructions to set up the dev instance, I was greeted with an ‘Unable to connect’ screen. (ERR_FAILED). Even using telnet from the same host failed:
bertieb@ubunutu-vm:~/discourse$ telnet 127.0.0.1 9292
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
Connection closed by foreign host.Dang. I tried this across fresh Arch and Ubuntu Server (19.10 + 18.04.3 LTS) installs and got the same thing.
Installing the non-Docker version worked but only for localhost; then a comment on that guide’s topic pointed me at a recent change to interface binding. Checking out the commit before that change let me connect from other hosts in both the Docker and non-Docker versions.
As of 2019-11-04 a later commit sorted this issues and added a specific flag (-b) for permitting connections from other hosts.