when I start docker container like this:
sudo docker run -p5432:5432 -d -e POSTGRES_PASSWORD=test_pass -e POSTGRES_USER=test_user -e POSTGRES_DB=test_db --name postgres postgres:12
I can see it's started by command sudo docker ps. But when I try to connect to the container from host using
psql -Utest_user -p5432 -h localhost -d test_db
it just hangs for several minutes and then reports that wasn't able to connect.
But when I add --net host option like this:
sudo docker run --net host -p5432:5432 -d -e POSTGRES_PASSWORD=test_pass -e POSTGRES_USER=test_user -e POSTGRES_DB=test_db --name postgres postgres:12
everything starts working as expected, I can connect to the postgresql the same psql command.
The same happens to other containers which I run, not only created from postgres:12 image.
I can only make requests to them when I set --net host option.
But I need to expose different ports like for example 2000:5432 to run, for example, several postgres containers simultaneously.
What should I do to make it work? My machine is Ubuntu:20, in case if it matters, and docker is fresh new one installed by instruction from the official site yesterday.
You can't connect to database container because by default it only allows connections from the localhost ( local machines in the same network ).
When you start docker container it makes it's own network ( usually in 172.0.0.0/something ip range).
When you set the flag -net host, docker takes your host's ip address for it's own, and that's why you are able to connect to the database ( because then you are both on the same network ).
The solution is either use the -net host flag, or to edit the config file for the database container to allow external connections which is not recommended.
I created a quarkus application with access to a postgresql database on localhost. After creating the native image I try to run the application with:
docker run -i --rm -p 8080:8080 quarkusimage
if I try a method with postman I have this result:
addEmployee
Hibernate:
select
nextval ('quarkus.hibernate_sequence')
2020-06-18 20: 43: 38,214 WARN [io.agr.pool] (Agroal_20041415421) Datasource '': Connection to localhost: 5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP / IP connections.
if i try to run the application with
docker run --net = "host" -i --rm -p 8080:8080 quarkusimage
the application accesses the database on localhost, but if I try a postman call it can't reach the service.
What am I doing wrong?
Thank you
This has to do with docker networking. When an application is run inside docker, then localhost is not the hosts localhost unless you use --net = "host".
Aside from using --net = "host", you can could use the IP of host instead of localhost in the URL.
As for the podman issue you mention, that sounds like a podman bug or limitation - I propose you consult the podman documentation and / or open an issue in the podman issue tracker.
Unsure if this is an issue with Docker for Mac, my Postgres installation (via Homebrew, or some other strange local issue going on.
Probably worth mentioning that I have never ran into this issue on Linux.
Here is a snippet from my docker-compose.yml file that uses the postgres image:
services:
postgres:
image: postgres
environment:
- POSTGRES_DB=some_db
- POSTGRES_USER=some_user
- POSTGRES_PASSWORD=supersecretpassword
ports:
- 5432:5432
After starting compose services docker-compose up, I can see my postgres container running (docker ps).
I can also connect to it directly via docker exec
docker exec -it <container_id> psql -d some_db -U some_user
Everything working as expected so far...
However, when I try to connect to my Docker postgres instance via my local psql client:
psql -h localhost -p 5432 -U some_user -d some_db
It is not connecting to the Docker instance of postgres and rather is trying to use my local postgres instance.
Now the strange part...
When I change the port binding in docker-compose.yml
from 5432:5432
to 5433:5432 (5433 can be any open port)
I am able to connect to the Docker postgres instance as expected via my local psql client:
psql -h localhost -p 5433 -U some_user -d some_db
# After being prompted for my password I'm in!
I don't mind binding to a different port, but I'm still so curious what's happening here!
Anyone know what is happening?
Am I just not able to bind to port 5432?
Is this a Docker for Mac thing?
Is there an issue in the way I installed Postgres?
Thanks!
i have two docker containers running, following the instructions given here: https://github.com/swri-robotics/bag-database.
I can now look at the database in the browser using: localhost:8080, so it's set up properly and running fine.
So my question is, how can I get the other container that is running on port 5432 to list the database with all the other databases that I have locally using psql - l?
Right now I can only look at it if I open the container first.
I run it like this:
docker run -d -p 5432:5432 --name bagdb-postgres -v /var/lib/bagdb-postgres:/var/lib/postgresql/data -h 127.0.0.1 -e POSTGRES_PASSWORD=password -e POSTGRES_USER=user -e POSTGRES_DB=bag_database mdillon/postgres:lastest
Thanks!
The programm is executed in a container. The intention of containers is to create a environment capsuled off your host operating system. You added some flags like -p and -v which define some connections between the host and the container. These are the only connections you have and you can use docker commands to connect to your container. It is not intended that you can execute code inside a container as if it was not inside a container. It is not exposed to your operating system and as far as I know there is no way to change that.
I'm trying to use a Docker container to run a PostgreSQL server, and connect with it from my host machine.
My configuration is:
Host machine: Mac OS X 10.10.5
Docker 1.10.1
I've done this:
Step 1: create a volume for permanent postgres data
docker volume create --name postgres_data
Step 2: Start the postgres instance
UPDATE: As suggested in comments, I specified port mapping when running the container
docker run --name my_postgres_container -e POSTGRES_PASSWORD=my_password -v postgres_data:/var/lib/postgresql/data -p 5432:5432 -d postgres:9.1
Step 3: connect to Docker instance by doing this:
docker run -it --link my_postgres_container:postgres --rm postgres:9.1 sh -c 'exec psql -h "$POSTGRES_PORT_5432_TCP_ADDR" -p "$POSTGRES_PORT_5432_TCP_PORT" -U postgres'
But I want to connect to that instance just by:
psql -h localhost -p 5432 -U postgres
Like if I had installed Postgres locally in my host machine.
The problem is port 5432 is not exposed. So, I can't connect with it:
sudo lsof -i -P | grep -i "listen" --> no port 5432 open
UPDATE 2: Even stranger. I've also done this:
Stop Docker. Then, run a normal PostgreSQL 9.4.4 instance in my host machine (no docker involved here, just postgres running in my Mac OS X host, listening on port 5432). Everything is normal:
sudo lsof -i -P | grep -i "postgres"
postgres 14100 jorge 6u IPv4 0x780274158cebef01 0t0 TCP localhost:5432 (LISTEN)
I can connect with my local postgres instance without any problem (look the output of the command: is the postgres compiled for Mac OS X, my host):
psql -h localhost -U postgres -c "select version()"
version
---------------------------------------------------------------------------------------------------------------------------------------
PostgreSQL 9.4.4 on x86_64-apple-darwin14.3.0, compiled by Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn), 64-bit
(1 row)
Now the fun part. I start my Docker instance again, while the host PostgreSQL instance is running.
It starts! (and it shouldn't). I can even connect using docker run...
docker run -it --link my_postgres_instance:postgres --rm postgres:9.1 sh -c 'exec psql -h "$POSTGRES_PORT_5432_TCP_ADDR" -p "$POSTGRES_PORT_5432_TCP_PORT" -U postgres'
If I run select version() now, it shows postgres running inside my docker instance at the same time postgres is running in my host, out of docker, using the same 5432 port. (Look at the ouput, is postgres compiled for Debian, the OS inside the postgres:9.1 container)
postgres=# select version();
version
------------------------------------------------------------------------------------------------
PostgreSQL 9.1.20 on x86_64-unknown-linux-gnu, compiled by gcc (Debian 4.9.2-10) 4.9.2, 64-bit
(1 row)
Why?
Does it make sense? My final goal is to run a Django app in another Docker container and connect with my Postgres instance. How could I do that?
It's 2018 and I just had a similar problem. The solution for me seemed to be with the order of props to docker. e.g. this resulted in no port being exposed;
docker run -d --name posttest postgres:alpine -e POSTGRES_PASSWORD=fred -p 5432:5432
while this worked fine (image exposed port 5432 as expected);
docker run --name posttest -d -p 5432:5432 -e POSTGRES_PASSWORD=fred postgres:alpine
Run the postgre image with the correct Port Mapping using -p <host_port>:<container_port>:
docker run --same-options-as-step-one -d -p 5432:5432 postgres:9.1
Your docker host is a virtual machine, which has it's own IP adddres.
You can detect this IP address by entering the following command:
docker-machine ip
The answer will be something like 192.168.99.100
When you have mapped the ports using the -p 5432:5432 switch, you will be able to connect to postgres with any tool from your dev machine using the IP address mentioned.
I was able to connect using container IP or host IP, except localhost (127.0.0.1).
To get container id run
docker ps
Find required container id and run
docker inspect --format='{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' <container_id>
Port must be exposed.
Here is an example of docker-compose.yml which starts two containers postgres and adminer, which is database management tool you can use to connect to postgres:
version: '3'
services:
adminer:
image: adminer
restart: always
ports:
- 8080:8080
postgres:
image: postgres:11.4-alpine
restart: always
ports:
- "5432:5432"
environment:
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
I had a similar issue. My problem was simply 0.0.0.0 not mapping to localhost so I just had to add to psql
psql --host=0.0.0.0
This is presuming
docker port <container name>
outputs
5432/tcp -> 0.0.0.0:5432
Other answers work, but don't explain why they work.
Given the command:
psql -h localhost -p 5432:5432 -U postgres
localhost is actually a special value that tells psql to look for a unix socket connection, instead of going over TCP. We can't use unix sockets to connect to docker services.
Changing the command like so fixes it, by forcing TCP:
psql -h 127.0.0.1 -p 5432:5432 -U postgres
That will work as long as you docker run ... -p 5432:5432 .... Specifying the IP returned by docker-machine ip also forces TCP, so that also works.
I had a similar problem working in a VMWare virtual machine with Lubuntu. The VM had been paused and then was restarted. The PostgreSQL Docker container was correctly mapped and listening on localhost:5432, but I always got:
psql: server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
Restarting the VM solved the problem in my case.
Try this to install postgresql
docker run --name postgres -d -p 5432:5432 -e POSTGRES_PASSWORD=fred postgres:alpine
Or Change port host machine Heree (mac)
docker run --name postgres -d -p 5436:5432 -e POSTGRES_PASSWORD=fred postgres:alpine
Tip:
Install pgadmin4
docker run -p 5050:80 -e "PGADMIN_DEFAULT_EMAIL=name#example.com" -e "PGADMIN_DEFAULT_PASSWORD=admin" -d dpage/pgadmin4