Getting DBConnection.ConnectionError connection refused error

Questions / Help
, , ,
1

Environment:

  • Windows 10

  • Using WSL2 with Ubuntu Server via Windows Terminal to run setup

  • Database URL: ecto://postgres:postgres@localhost/chat_api_dev

  • Error: ** (DBConnection.ConnectionError) tcp connect (localhost:5432): connection refused - :econnrefused
    (db_connection 2.2.2) lib/db_connection/connection.ex:87: DBConnection.Connection.connect/2
    (connection 1.0.4) lib/connection.ex:622: Connection.enter_connect/5
    (stdlib 3.13) proc_lib.erl:226: :proc_lib.init_p_do_apply/3
    Last message: nil
    State: Postgrex.Protocol
    ** (Mix) The database for ChatApi.Repo couldn’t be created: killed

I have validated that postgresql service is running in WSL2 by doing “sudo service postgresql status” which returns “13/main (port 5432): online”

I also run “netstat -an | grep 5432” which validates the port is listening

Also do “telnet localhost 5432” which connects fine

2

When you netstat can you output the IP it binds to? (If that is also a localhost ip it does not allow access from outside the wsl2 vm but can be accessed from inside the vm)

Comparing WSL 2 and WSL 1 | Microsoft Docs You could try to access it on it’s own VM IP to see if that works.

If it is all working from inside WSL2 it could also be a firewall rule blocking going from outside to WSL2.

3

I was curious about that, still understanding the mechanics of WSL2. I have a Postgres service on my Windows machine that is not the same (from my understanding) as as the one running within the WSL2.

When I do the netstat mentioned above this is what it outputs:
tcp 0 0 127.0.0.1:5432 0.0.0.0:* LISTEN
unix 2 [ ACC ] STREAM LISTENING 20997 /var/run/postgresql/.s.PGSQL.5432

I did try to setup the Postgres instance on Windows and access that via ip bu then receive the “non-existing domain - :nxdomain” error.
I have an inbound windows firewall rule to allow all incoming traffic from the WSL2 IP to port 5432

WSL2 IP when running ifconfig: 172.24.95.116
Windows IPv4: 172.24.80.1

4

Did you already try to use that 172.24.95.116 ip (the WSL2 ip) for the ecto connect string instead of localhost?

5

I did, if I do that I receive the following

10:53:14.808 [error] GenServer #PID<0.1557.0> terminating
** (DBConnection.ConnectionError) tcp connect (172.24.95.116:5432): non-existing domain - :nxdomain
    (db_connection 2.2.2) lib/db_connection/connection.ex:87: DBConnection.Connection.connect/2
    (connection 1.0.4) lib/connection.ex:622: Connection.enter_connect/5
    (stdlib 3.13) proc_lib.erl:226: :proc_lib.init_p_do_apply/3
Last message: nil
State: Postgrex.Protocol
** (Mix) The database for ChatApi.Repo couldn't be created: killed
6

Update: Never resolved the issue. Just switched to running the app on my Windows machine instead of in WSL2.