Add support for UNIX sockets

[jeroenhabets]

As per processone/ejabberd#3716 (comment) this library lacks support for UNIX sockets, thus blocking adding PostgreSQL UNIX socket support to ejabberd (also requested in processone/ejabberd#3165).

Now that Erlang has (stable) UNIX socket support for a while, a.o. used by ejabberd itself, it should be feasible.

[badlop]

Ok, I wrote a small patch, it's committed in badlop@35550c5

And the corresponding update in ejabberd is badlop/ejabberd@b90e7fa

With that, ejabberd.yml may be configured with

sql_server: "unix:/var/run/postgresql/.s.PGSQL.5432"

It worked for me, please give it a try. If you need binary installers or containers for testing, tell me.

[jeroenhabets]

Wow @badlop 🥇! Amazing response time here.

As I had never run ejabberd from source before it took my an hour to get it running as I wanted to help out testing. But then I got it to run successfully using both the old TCP/IP and new UNIX domain socket connection for PostgreSQL. NOTE: I just did a smoke test and my conversejs is happy with either server 👍 .

[Jieiku]

Thank you very much for this @badlop , that is Awesome!

@jeroenhabets did you keep any notes for compiling/running from source? My instance of ejabberd is installed from a .deb file.

[jeroenhabets]

@Jieiku I did :)

My starting point was:
https://github.com/processone/ejabberd/blob/master/COMPILE.md

For the tests I did:

git clone git@github.com:badlop/ejabberd.git ejabberd_badlop
cd ejabberd_badlop
git checkout pgsql-unix-socket

./autogen.sh
## Depends on your config / modules of course:
./configure --enable-pgsql --enable-zlib --enable-redis  --enable-stun --enable-sip --enable-new-sql-schema 
make prod

## Copy my config for this test (make a db backup first ;)) 
sudo cp /opt/ejabberd/conf/ejabberd.yml _build/prod/rel/ejabberd/conf/ejabberd.yml
## Don't forget to edit it (e.g. sql_server: "unix:/var/run/postgresql/.s.PGSQL.5432")
_build/prod/rel/ejabberd/conf/ejabberd.yml

## Run in foreground: (shutdown using Ctrl-C then choose a)
_build/prod/rel/ejabberd/bin/ejabberdctl live

Hope this is of any help to you...

[badlop]

This was committed in 996001d, and will be available in the next p1_pgsql release.