Docker - Postgres and pgAdmin 4 : Connection refused - postgresql

Question

Newbie with docker, I am trying to connect throught localhost my pgAdmin container to the postgres one.
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0b00555238ba dpage/pgadmin4 "/entrypoint.sh" 43 minutes ago Up 43 minutes 0.0.0.0:80->80/tcp, 443/tcp pedantic_turing
e79fb6440a95 postgres "docker-entrypoint.s…" About an hour ago Up About an hour 0.0.0.0:5432->5432/tcp pg-docker
I succeed connecting with psql command.
psql -h localhost -U postgres -d postgres
But when I create the server on pgAdmin with the same parameters as psql I got the following error.
Unable to connect to server:
could not connect to server: Connection refused Is the server running
on host "localhost" (127.0.0.1) and accepting TCP/IP connections on
port 5432? could not connect to server: Address not available Is the
server running on host "localhost" (::1) and accepting TCP/IP
connections on port 5432?
I succeed to connect throught the IPAddress given by docker inspect on the container.
By the way, I checked postgresql.conf and assert that listen_addresses = '*' and also that pg_hba.conf contain host all all all md5.
But I don't get it, why shouldn't I be able to use the localhost address ? And why does docker even give me an address that is not local ?

Answer 1

In this case:
Pgadmin fails to connect to localhost, but psql works from outside docker.
both pgadmin & Postgres are running as Containers
Although you haven't indicated if you are doing so, ideally both containers could be part of a custom bridge network for automatic DNS resolution.
If not added explicitly they will be part of the default bridge network.
To find out the networks created in your docker runtime, type:
$ docker network ls
Some networks will be listed in the console, maybe you'll find a [name]_default it should be your network.
Execute
docker network inspect [name]_default
it'll show up a bunch of information, for us the most important is IPv4Address, something like this:
"7c3cd7532ab8aacc70830afb74adad7296d9c8ddd725c498af2d7ee2d2c2aadd": {
"Name": "intime_postegres_1",
"EndpointID": "56a9cb574469f22259497b72719f9f4a3e555b09f95058fcf389ef5287381f28",
"MacAddress": "02:42:ac:12:00:02",
"IPv4Address": "172.18.0.2/16",
"IPv6Address": ""
}
Instead of using localhost for the server name/ip in the pgAdmin new server dialog, connect to the postgres instance's "IPv4Address".
In my case connecting at 172.18.0.2:5432, worked like a charm.

Answer 2

I too had the case when you're able to connect with psql command on terminal but not with pgAdmin4.
The following solution worked for me.
First -
docker ps
From there you'll get the container name/ID of the postgres container, then do -
docker inspect name_of_container_here
It'll give you something like this -
"Networks": {
"bridge": {
"IPAMConfig": null,
"Links": null,
"Aliases": null,
"NetworkID": "f35dbe66b36cd38673aad6e1278ad33031ef9d5abd34582d4b91955e288f855e",
"EndpointID": "2e63ea59e9d0de7526bb02ba29bc0b16bcad51b8963127ad380416d15da994db",
"Gateway": "172.17.0.1",
"IPAddress": "172.17.0.2",
"IPPrefixLen": 16,
"IPv6Gateway": "",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"MacAddress": "02:42:ac:11:00:02",
"DriverOpts": null
}
}
Note the IPAddress and provide that while creating a new server in pgAdmin4 -

Answer 3

I had the same issue and I solved it in a non-canonical way, but very satisfactory to my local workflow.
I always start my postgresql container with a docker-compose.yaml file. So I just added the pgAdmin to the same compose file:
version: "3.7"
services:
my_awesome_db:
image: postgres:latest
ports:
- "5432:5432"
container_name: postgresql-local
volumes:
- "/var/run/postgres.sock:/var/run/postgres/postgres.sock"
- "/home/myuser/docker-apps/volumes/postgres-data:/var/lib/postgresql/data"
pg_admin:
image: dpage/pgadmin4:latest
container_name: pgadmin4
ports:
- "15432:80"
environment:
- GUNICORN_THREADS=1
- PGADMIN_DEFAULT_EMAIL=my_awesome_email#email.com
- PGADMIN_DEFAULT_PASSWORD=does_not_matter
depends_on:
- my_awesome_db
So I access pgAdmin on my localhost:15432 (just because it's easy to remember), and I've configured pgAdmin with:
Host: my_awesome_db
Port: 5432
Username: postgres

Answer 4

For me worked like this:
Add Server -> Connection -> Hostname/address
Set field to 172.17.0.1
More info at Docker Network doc: https://docs.docker.com/network/network-tutorial-standalone

Answer 5

You just need to specify in your connection string the, server parameter, the name of your container name and not the localhost or 127.0.0.1

Answer 6

first you need to get container information
$docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0b00555238ba dpage/pgadmin4 "/entrypoint.sh" 43 minutes ago Up 43 minutes 0.0.0.0:80->80/tcp, 443/tcp pedantic_turing
e79fb6440a95 postgres "docker-entrypoint.s…" About an hour ago Up About an hour 0.0.0.0:5432->5432/tcp pg-docker
then extract IP Address
$sudo docker inspect e79fb6440a95 | grep IPAddress
"SecondaryIPAddresses": null,
"IPAddress": "",
"IPAddress": "192.168.64.2",
And when you create your server put your IP Address

Answer 7

Because I was connecting to a server on the hose, it was as simple as adding
--net host
to the docker run command, so that the container gets access to the host's ports.