Error creating postgres container with Docker - postgresql

I'm initializing my studies with docker. When I creating the postgreSQL container with Docker, appear this error:
I've already reinstall docker and tried change the database port, but must be don't have success

The error indicates that the 5432 port is already in use, in the HOST. This means that this port is occupied by another application. This could be for example a Postgres instance that you have on your machine or maybe another container using up this port.
The port option is -p hostPort:ContainerPort, so to have access to the Postgres port of the container which is 5432 in the host at port 5000 try:
-p 5000:5432

Related

Docker postgres connection from *inside* docker container to host machine's postgres localhost instance on a Mac

All the questions on SO about this seem to refer to an opposite case of creating a postgres container and connecting it from Mac host. But I am trying to do the opposite, without success. I have localhost running on my Mac host machine, and despite setting port flags, I cannot get code inside my container to talk to my localhost postgres (talks to remote host postgres just fine).
docker run -it -p 5000:5000 -p 5432:5432 yard-stats
Then inside docker:
telnet 0.0.0.0 5432
Trying 0.0.0.0...
telnet: Unable to connect to remote host: Connection refused
or telnet 127.0.0.1 or localhost. Connection is refused.
Edit: I also tried with flag --network="host", which did not change anything except break inbound connections to the container on localhost:5000 as well.
If you are using docker for mac, you can use use host.docker.internal special DNS name which resolves to the internal IP address used by the host.
You can also use --network="host" with your docker run command to run the container in host network. Then the localhost interface inside the container will be same as localhost interface of the host machine when run in host network. So you should be able to use localhost:5432 to connect to postgresql. You can remove -p option as it has no effect when running with --network="host".
docker run -it --network=host yard-stats

Docker Rundeck + local Postgres

I'm trying to run a docker image of rundeck, using PostGres for the database.
The issue I'm having is mapping my local postgres installation to the docker rundeck image. The postgres port runs on 5432, and have confirmed using netstat that the port is open and listening. The port for rundeck needs to run on 4440.
I have tried the following command:
docker run -p 127.0.0.1:4440:4440 -e RUNDECK_DATABASE_URL=jdbc:postgresql://localhost/rundeck -e RUNDECK_DATABASE_DRIVER=org.postgresql.Driver -e RUNDECK_DATABASE_USERNAME=xxx -e RUNDECK_DATABASE_PASSWORD=xxx --name test-rundeck -t rundeck/rundeck:3.0.19
But it fails with an error: Connection to 127.0.0.1:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP
I'm guessing it's because the internal 5432 port isnt mapped to the docker container port 5432?
I tried mapping the ports with -p 127.0.0.1:5432:5432 but that fails with the error:
Error starting userland proxy: listen tcp 127.0.0.1:5432: bind: address already in use
At this point I might just resort to running both PostGres and Rundeck as docker images, but I would rather like to resolve this problem.
Any ideas on how to map a local PostGres to a docker ran Rundeck?
Found the answer.
Had to edit the pg_hba.conf file to allow the docker0 ip address through.
host all all 172.23.0.0/16 md5

Connect to Windows Postgres from Debian Docker container

I am running Postgres on a Windows 10 computer, and I want to connect to it from a Docker container. I've followed instructions from many sources and things should be working, but they're not.
Command line used to create Docker container:
docker run --rm -d --network=host --name mycontainer myimage
In postgresql.conf:
listen_addresses = '*'
In pg_hba.conf:
host all all 172.17.0.0/16 trust
In the bash shell of my container, I run:
psql -h 127.0.0.1
and I get the error:
psql: could not connect to server: Connection refused
Is the server running on host "127.0.0.1" and accepting TCP/IP connections on port 5432?
Needless to say, Postgres is definitely running on my computer and I am able to query it from local applications. What am I missing?
THIS WON'T WORK FOR DOCKER v18.03 AND ONWARDS
The answer is already there - From inside of a Docker container, how do I connect to the localhost of the machine?
This question is related to a mysql setup, but it should work for your case too.
FOR DOCKER v18.03 ONWARDS
Use host.docker.internal to refer to the host machine.
https://docs.docker.com/docker-for-windows/networking/#i-cannot-ping-my-containers
As you've discovered, --network-host doesn't work with Docker for Windows or Docker for Mac. It only works on Linux hosts.
One option for this scenario might be to host PostgreSql in a container, also. If you deploy them with a docker-compose file, you should be able to have two separate Docker containers (one for the database and one for your service) that are networked together. By default, docker-compose will expose containers to others in the same compose file using the container name as its DNS name.
You could also consider including the database in the same container as your service, but I think the docker-compose solution is better for several reasons:
It adheres to the best practice of each container having only a single process and single responsibility.
It means that you can easily change and re-deploy your service without having to recreate the database container.
Configure the connection inside your docker container with the real ip-address of your host or as workaround with a dns name

Unable to connect containerized app to containerized postgres, receiving dial tcp connection refused error

This community is my last resort for this problem, as I have been fighting with this for several hours now.
I have a go app running in one container, in the other container I am running a postgres db. I am able to connect to the postgres db from my go application as long as only my postgres is within a container, and my go app is running locally as usual. However, when my go app is trying to access the postgres from within a docker container i am getting the following error:
dial tcp 127.0.0.1:8080: connect: connection refused
Below I try to provide enough information, but will gladly add more if requested.
I have 2 docker containers running with the following ports:
go application, port info: 8081/tcp -> 0.0.0.0:8081
postgres db, port info: 5432/tcp -> 0.0.0.0:8080
I am running the go app with:
docker run -it --rm --name gographqlserver --link postgresdb:postgres -d -p 8081:8081 gogogopher;
and the postgres db with:
docker run -it --rm --name postgresdb -e POSTGRES_PASSWORD=hello123 -d -p 8080:5432 postgresimage;
both containers can be started without any problems.
I have also tried connecting both containers within a docker network, which did not help.
help would be immensely appreciated!
You are using localhost address within the container which is not the same as your host's address. You should do one of the following instead:
Use your actual host's IP from app's container
Use postgresdb container's IP with the native port (5432). You can discover this IP using docker inspect postgresdb.
Use postgresdb as host name and the native port (5432) when connecting both containers to the same network

Allowing Docker container to access Postgres running on localhost

I've got a docker container which is supposed to run a (HTTP) service.
This container should be able to connect to PostgresSQL running on the host machine (so it's not part of the container). The container uses the host's network settings:
docker run -e "DBHOST=localhost:5432" -e "DB=somedb" -e "AUTH=user:pw" -i -t --net="host" myservice
I'm using MacOSX, so Docker is running on a Virtualbox VM. I guess I need port forwarding to make this work. I've tried to configure that:
VBoxManage controlvm "default" natpf1 "rule1,tcp,,5432,,5432";
But this doesn't work. If I start up the service, all I get is a connection refused message and the service cannot connect to Postgres.
Postgres is running on port 5432, on the host machine. The "default" is the name of the VM created by Docker installer.
What am I doing wrong? Please help!
I've had success with this using the --add-host flag, which adds an entry into the /etc/hosts in your container. Boot2docker and docker-machine both assign an ip you can use to hit your localhost from inside a container, so you just want to add an entry that points back to this.
With boot2docker, where the default host ip is 192.168.59.3, you can just do docker run --add-host=my_localhost:192.168.59.3 ...
With docker-machine, I think you'll need to lookup your localhost's mapped ip in Virtualbox, and then you can do the same: docker run --add-host=my_localhost:[localhost_mapped_ip_from_docker] ...
Try setting that up and then trying to connect to your Postgres instance through my_localhost. Make sure you correctly set access and accepted inbound ip permissions in Postgres as well, as if it's not listening on the container's ip or 0.0.0.0, it won't work no matter what.