I am learning Docker. I have practiced a lot, including testing commands from the official Postgres page on dockerhub.
I ran this command:
docker run -it --rm --network some-network postgres psql -h some-postgres -U postgres
Could someone give a complete and concrete example to make this command work (i mean with a real existing container). I can't see how it could work.
docker run create a docker container
-it create a connection to said container (kinda like TTY) taking in what we write into interactive bash in the container
--rm delete the container when it exit
--network some-network assign some-network network to the container
postgres name of the image
psql -h some-postgres -U postgres connect to PostgreSQL at some-postgres address using postgres user.
Combine the entire command and flags: create a PostgreSQL container and the use the psql command from inside the container to connect to some-postgres using postgres user
For more flags and usage, you can learning from the doc here
Probably, in the Docker hub page is not perfectly clear but your command is used to connect to an already existing Postgres instance.
So, for example, you first create a container with the command:
docker run -it --rm --name postgresql -p 5432:5432 -e POSTGRES_USER=admin -e POSTGRES_PASSWORD=admin -d postgres:latest
then you can execute your command to connet to it
docker run -it --rm postgres psql -h <your_ip> -U postgres
If your container is running locally, you can get the ip from the bash command ip address
The network attibute is related to the container you first startup so you can decide to leave or remove from the command in relation to the container deploy.
I have created a docker container based on a postgres image.
Which I try to connect to from a Spring Boot application with no success.
The user is 'postgres', and the password 'password'.
(I don't have anything from Docker Compose, nor do I know if it's necessary.)
I would appreciate any help
Finally solved:
Remove all previous containers.
Create new container. This time using port 5433 and expecifying the postgres user.
docker run --name container-postgres-1 -p 5433:5432 -v "C:\volumen-docker-1:/var/lib/postgresql/data" -e POSTGRES_PASSWORD=password -e POSTGRES_USER=postgres -d postgres:13.9-alpine3.17
Create the database bootifyone.
docker exec -it container-postgres-1 bash
psql -h localhost -p 5432 -U postgres
CREATE DATABASE bootifyone;
Using this connection URL in the application.properties:
spring.datasource.url=jdbc:postgresql://localhost:5433/bootifyone
I have Postgresql on a server in a docker container. How can I connect to it from the outside, that is, from my local computer? What setting should I apply to allow that?
You can run Postgres this way (map a port):
docker run --name some-postgres -e POSTGRES_PASSWORD=mysecretpassword -d -p 5432:5432 postgres
So now you have mapped the port 5432 of your container to port 5432 of your server. -p <host_port>:<container_port> .So now your postgres is accessible from your public-server-ip:5432
To test:
Run the postgres database (command above)
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
05b3a3471f6f postgres "/docker-entrypoint.s" 1 seconds ago Up 1 seconds 0.0.0.0:5432->5432/tcp some-postgres
Go inside your container and create a database:
docker exec -it 05b3a3471f6f bash
root#05b3a3471f6f:/# psql -U postgres
postgres-# CREATE DATABASE mytest;
postgres-# \q
Go to your localhost (where you have some tool or the psql client).
psql -h public-ip-server -p 5432 -U postgres
(password mysecretpassword)
postgres=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+------------+------------+-----------------------
mytest | postgres | UTF8 | en_US.utf8 | en_US.utf8 |
postgres | postgres | UTF8 | en_US.utf8 | en_US.utf8 |
template0 | postgres | UTF8 | en_US.utf8 | en_US.utf8 | =c/postgres
So you're accessing the database (which is running in docker on a server) from your localhost.
In this post it's expained in detail.
I managed to get it run on linux
run the docker postgres - make sure the port is published, I use alpine because it's lightweight.
docker run --rm -P -p 127.0.0.1:5432:5432 -e POSTGRES_PASSWORD="1234" --name pg postgres:alpine
using another terminal, access the database from the host using the postgres uri
psql postgresql://postgres:1234#localhost:5432/postgres
for mac users, replace psql with pgcli
You can also access through docker exec command by:
$ docker exec -it postgres-container bash
# su postgres
$ psql
Or
$ docker exec -it postgres-container psql -U postgres
I am using django with postgres in Docker containers. in the docker-compose file, add the following:
db:
image: postgres:10-alpine
environment:
- POSTGRES_DB=app
- POSTGRES_USER=postgres
- POSTGRES_PASSWORD=supersecretpassword
ports:
- "6543:5432"
This ports setting uses the port 6543 (it just needs to be different from 5432) that is accessible by your local machine. For myself, I connected DBeaver to it. this will prevent port clashes between your app request and local machine request.
At first, I got a message saying that the port 5432 is in use (which is by django app) so I couldn't access by pgAdmin or DBeaver.
I'm assuming that you want to be able to view data present in your container everytime you connect to it from outside. To do this, you will have to persist data on the postgres image.
If you dont have persistant data, you will have to repeat everything you did the first time.
Steps 3, 5, 6, 7, and 8 answer your question directly.
Here is the detailed overview of the entire process I followed on Windows 10 powershell (commands are the same in Linux and macOS as well):
Step 1: Start powershell in non-admin mode
Step 2: Download postgres docker image:
docker pull postgres:latest
Step 3: Start docker container in detached mode and persist data on postgres image by creating a volume and binding it to a destination
(Note: by default 5432 is the default port that is used; but state it explicitly to prevent connection errors from clients like pgadmin, dbeaver, etc.)
docker run --name postgres-test -e POSTGRES_PASSWORD=password -p 5432:5432 -v postgres-data:/var/lib/postgresql/data -d postgres:latest
Step 4: Check status of running containers
docker ps -a
Step 5: Go inside container_name in interactive mode
(Note: commands like ls, pwd, etc. can be executed here if you've checked linux containers during installation)
docker exec -it postgres-test psql -U postgres
Step 6: Create sample data. At this point, you can play with psql commands in the following manner:
# CREATE DATABASE test;
# \c test
# CREATE TABLE test_table(something int);
# INSERT INTO test_table VALUES (123);
# SELECT * FROM test_table;
# \q
Step 7: Open a database client application like pgadmin or dbeaver and enter the below in the connection fields:
Host: localhost
Database: test
User: postgres
Password: password
Step 8: Enter the query select * from test_table in the query editor and you should be able to see the output 123
I know this is late, if you used docker-compose like #Martin
These are the snippets that helped me connect to psql inside the container
docker-compose run db bash
root#de96f9358b70:/# psql -h db -U root -d postgres_db
I cannot comment because I don't have 50 reputation. So hope this helps.
I already had running postgres on host machine and didn't want to allow connections from network, so I did run temporary postgres instance in container and created database in just two lines:
# Run PostgreSQL
docker run --name postgres-container -e POSTGRES_PASSWORD=password -it -p 5433:5432 postgres
# Create database
docker exec -it postgres-container createdb -U postgres my-db
For some reason 5432 port seems protected. I changed my port config from 5432:5432to 5416:5432 and the following command worked to connect to your postgres database from outside its docker container:
psql -h localhost -p 5416 -U <my-user> -d <my-database>
To connect from the localhost you need to add '--net host':
docker run --name some-postgres --net host -e POSTGRES_PASSWORD=mysecretpassword -d -p 5432:5432 postgres
You can access the server directly without using exec from your localhost, by using:
psql -h localhost -p 5432 -U postgres
Connect to a local container running postgres
Install psql
brew search postgres
brew install postgresql
2.
docker run --name postgres -e POSTGRES_DB=users \
-e POSTGRES_USER=john \
-e POSTGRES_PASSWORD=password \
-p 5432:5432 -d postgres
psql --host=localhost --username=john --dbname=users
I tried to connect from localhost (mac) to a postgres container. I changed the port in the docker-compose file from 5432 to 3306 and started the container. No idea why I did it :|
Then I tried to connect to postgres via PSequel and adminer and the connection could not be established.
After switching back to port 5432 all works fine.
db:
image: postgres
ports:
- 5432:5432
restart: always
volumes:
- "db_sql:/var/lib/mysql"
environment:
POSTGRES_USER: root
POSTGRES_PASSWORD: password
POSTGRES_DB: postgres_db
This was my experience I wanted to share. Perhaps someone can make use of it.
first open the docker image for the postgres
docker exec -it <container_name>
then u will get the root --root#868594e88b53:/#
it need the database connection
psql postgresql://<username>:<databasepassword>#postgres:5432/<database>
This one worked for me:
PGPASSWORD=postgres psql -h localhost -p 3307 -U postgres -d postgres
Use the above to load an initial script as:
PGPASSWORD=postgres psql -h localhost -p 3307 -U postgres -d postgres < src/sql/local/blabla.sql
Do not that i remap my ports as:
docker run -p3307:5432 --name postgres -e POSTGRES_PASSWORD=postgres -d postgres
In case, it is a django backend application, you can do something like this.
docker exec -it container_id python manage.py dbshell
After building my gateway-microservice application i had the same issue. Can not to connect to contenerized postgresql from Heidisql.
At this moment i have solved it by simply specifying postgresql password to docker-compose.yml as well as port.
So you should find and open docker-compose.yml. Then you should enter POSTGRES_PASSWORD (don`t let it to be empty), and specify the port “5432:5432”
services:
microservice33-postgresql:
environment:
- POSTGRES_USER=microservice33
- POSTGRES_PASSWORD=wwww
- POSTGRES_HOST_AUTH_METHOD=trust
ports:
- 5432:5432
link for reference and screenshots post
There are good answers here but If you like to have some interface for postgres database management, you can install pgAdmin on your local computer and connect to the remote machine using its IP and the postgres exposed port (by default 5432).
docker ps -a to get container ids then
docker exec -it psql -U -W
I used to create postgresql database for my old project with command:
docker run --name oldpostgresqldb -e POSTGRES_USER=oldadmin -e POSTGRES_PASSWORD=secret -p 5432:5432 -v /data:/var/lib/postgresql/data -d postgres
Then create database with command:
docker exec -i oldpostgresqldb psql -U oldadmin -c "CREATE DATABASE oldDB WITH ENCODING='UTF8' OWNER=oldadmin;"
When I started my new project stoped and removed all containers, images, volumes etc. and even used docker system prune.
Now I am trying to create new container and db with commands:
docker run --name newpostgresqldb -e POSTGRES_USER=newadmin -e POSTGRES_PASSWORD=secret -p 5432:5432 -v /data:/var/lib/postgresql/data -d postgres
and
docker exec -i newpostgresqldb psql -U newadmin -c "CREATE DATABASE newDB WITH ENCODING='UTF8' OWNER=newadmin;"
But I receive psql: error: FATAL: role "newadmin" does not exist.
Furthermore, I still can manage oldDB with oldadmin user in newpostgresqldb container, because user oldadmin is still exists.
How can I delete old data and create new user and database using docker?
Thanks to #Ay0 I've found a solution. I just needed to clear content of /data folder in the host directory manualy.
I have a Postgres 9.5.4 database running inside a docker container. I am using the official Postgres images and I have been trying to create backups from my database, but not luck so far. According docker documentation I was expecting the following command to store the dump.tar file in the /releases/ folder in the host machine (outside the temporal docker container)
docker run -i --rm --link my_postgres:postgres --volume /releases/:/tmp/ postgres:latest pg_dumpall > /tmp/dump.tar
But this throws the following error:
pg_dumpall: could not connect to database "template1": could not connect to server: Connection refused
Is the server running locally and accepting
connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?
Any idea what could be wrong?
Actually I have found the solution
docker run -i --rm --link my_container:postgres -v /releases/:/tmp/ postgres:latest bash -c 'exec pg_dumpall -h "$POSTGRES_PORT_5432_TCP_ADDR" -p "$POSTGRES_PORT_5432_TCP_PORT" -U postgres > /tmp/my_backup.tar'
Where Docker arguments:
-i For interactive processes, like a shell, bash, etc.
--rm For deleting the container once the backup is finished
--link For linking this temporal container to my_container, which contains the currently running Postgres database.
-v /releases/:/tmp/ Creates shared volume. The content inside the folder /tmp/ in the container (In this case my_backup.tar) will be automatically visible on folder /releases/ in the host machine.
And bash arguments:
pg_dumpall To export PostgreSQL cluster into a script file.
-h "$POSTGRES_PORT_5432_TCP_ADDR" Obtains the ip address out of the Postgres variable.
-p "$POSTGRES_PORT_5432_TCP_PORT" Obtains the Port out of the Postgres variable (These variables are defined only in the temporal container we just created, as result of the linkage with my_container)
-U The username for connecting to the database