Docker with Postgresql - postgresql

I create an Dockerfile with Postgresql with this code:
FROM postgres:9.4
MAINTAINER Fabio Ebner
ENV POSTGRES_PASSWORD="dna44100"
ENV POSTGRES_PORT=5432
EXPOSE ${POSTGRES_PORT}
COPY init.sql /docker-entrypoint-initdb.d/
so How can I specify to always save my db data in my user Machine? cause with this code everty time I stop the container my data are lost

You will need to mount a volume. pointing your host machine to the container's directory /var/lib/postgresql
Source: docker mounting volumes on host

You need to mount a volume to the data directory of PostgreSQL.
You can use the following, using the docker-compose file:
version: "3"
services:
test-postgresql:
image: postgres:9.4
container_name: test-postgresql
ports:
- "5432:5432"
environment:
POSTGRES_PASSWORD: dna44100
volumes:
- ./init.sql:/docker-entrypoint-initdb.d/init.sql
- ./folder-on-host:/var/lib/postgresql/data
With the docker-compose file you can start the container with docker-compose up and stop the container with docker-compose down. The database and settings are saved on the specified directory (./folder-on-host).
If you want to remove the volume you can use the command: docker-compose down -v
You can also use the docker run to mount a volume, using the -v or -volume option:
docker run -v ./folder-on-host:/var/lib/postgresql/data yourimagename

Related

Reusing postgresql database from volume in docker-compose

When I created volume in Docker using command:
docker volume create pg-data
Then I set up basic postgresql database from postgres image:
docker run --rm -v pg-data:/var/lib/postgresql/data --name pg-docker -e POSTGRES_PASSWORD=docker -p 5433:5432 postgres
Everything worked fine. Database persist and I can even access it directly from the host. I created several roles here like app_user_1.
Now then I wanted to spin up postgresql in container using docker-compose. I shutdown the above postgresql container beforehand.
There I have this settting:
version: '3.7'
services:
db:
image: postgres
volumes:
- pg-data:/var/lib/postgresql/data/
expose:
- 5432
restart: always
environment:
- POSTGRES_PASSWORD=docker
- POSTGRES_USER=postgres
web:
build: .
volumes:
- ./app:/app
ports:
- 8001:8000
environment:
- ENVIRONMENT=dev
- TESTING=0
depends_on:
- db
volumes:
pg-data:
However it seems that even though I mapped the same volume and used same env settings as in docker run command the postgresql instance in container created with docker-compose has no databases and no roles at all.
I get the following error:
psql: error: FATAL: role "postgres" does not exist
or
psql: error: FATAL: role "app_user_1" does not exist
So it seems it behaves as though as it is different instance of postgresql.
When I restarted the first container with docker run everything was there (all the databases and roles).
Any idea why this is happening? How can I reuse the databases from the first container in the docker-compose?
You need to define the volume you wish to use (the one you created manually with docker volume create as external to docker-compose as it was created externally
This is because the volumes created by docker-compose are 'internal' to it, so using ones created by just docker are 'external'. =)
Ref the offical docs at https://docs.docker.com/storage/volumes/#use-a-volume-with-docker-compose
The change to your compose file would be as follows:
...
volumes:
pg-data:
external: true
(Just that last line)
Hope that helps! =)
Additional Note
You can confirm this, by performing a docker volume ls | grep pg-data command which will list all volumes, then only show you the ones referencing 'pg-data'.
On my system where I was testing before I gave my answer, I get the following:
docker volume ls | grep pg-data
local pg-data
local postgresstackoverflow_pg-data
As you can see, the docker volume create one is listed first, as a local volume called 'pg-data', then the docker-compose.yml created one is next prefixed by the naming convention of docker-compose with the directory name that it was in at the time.

docker postgres not able to change pgdata permissions

I have a project where I use google compute engine to host my app and docker to containerize it.
I have a postgres image and I want to use a volume to make my data persistent when I restart the container. Moreover I want the db data to be stored in google storage. So I have a google storage bucket and I have mounted a directory in my google compute engine to that bucked. Specifically what I did is mkdir /home/vetter_leo/data where data is the folder I want to use as a volume and then I mount it using gcsfuse --dir-mode 777 --file-mode 777 -o allow_other --implicit-dirs artifacts.helenos-273112.appspot.com /home/vetter_leo/data/.
My dockerfile for the postgres image is this :
FROM postgres:latest
USER postgres
ENV POSTGRES_USER helenos
ENV POSTGRES_PASSWORD helenos
ENV POSTGRES_DB helenos
ENV PGDATA /var/lib/postgresql/data/pgdata
COPY init_helenos_schema.sql /docker-entrypoint-initdb.d/
EXPOSE 5432
and my docker-compose file is this :
version: "3.5"
services:
postgres:
container_name: postgres
image: postgres
build:
context: .
dockerfile: ./postgres.prod.dockerfile
volumes:
- /home/vetter_leo/data:/var/lib/postgresql/data
networks:
default:
external:
name: helenos-network
When doing docker-compose -f docker-compose.yml up -d --build I end up with the container not being started and this error is shown chmod: changing permissions of '/var/lib/postgresql/data/pgdata': Operation not permitted.
I have searched the web but so far I have not been able to find a solution for my problem. Any help would be greatly appreciated. Thanks.
I ended up using a persistend disk as sugested by #mebius99 and it works so no problem anymore.

How to delete postgres database within docker container

I am trying to figure out how to completely remove a docker container with a postgres database and rebuild using docker-compose?
I created a server and database container using docker-compose. The database did not get set up how I wanted, so I would like to remove the database and rebuild. I assumed the easiest solution, given it is brand new would be to stop the container from running, remove the container and then run docker-compose again.
I have followed those steps, do not see any of the containers. I do not see any volumes associated with the containers. However, when I run docker-compose it appears to be using the postgres database that was previously created?
Here is what my docker-compose files consists of with user/password/db name extracted.
services:
server:
image: "node:10"
user: "node"
working_dir: /home/node/app
volumes:
- ./:/home/node/app
ports:
- 3030:3030
command: "npm start"
depends_on:
- db
db:
image: postgres:latest
restart: always
environment:
POSTGRES_USER: [user]
POSTGRES_PASSWORD: [password]
POSTGRES_DB: [db_name]
volumes:
- ./data/postgres:/var/lib/postgresql/data
I expected that by using:
docker stop [container] to stop the container, then
docker rm [container] to remove the container
I could rebuild fresh with docker-compose up
You can list the volumes used by docker with this command:
docker volume ls
Then, if needed, you can inspect the volumes to find which one your database uses:
docker volume inspect xyzvolumename
After locating the volume used by your database, delete it for a fresh start:
docker volume rm locatedvolumename
Docker stop and docker rm will not work untill you remove bind mount volume from your docker-compose.
Remove this from your docker-compose
- ./data/postgres:/var/lib/postgresql/data
or delete everything from host directory inside
./data/postgres

How to persist data on a volume when using docker swarm mode?

New to Docker and I'm trying to set Postgres and pgadmin4 to run as a single service on docker for Mac inside a virtual machine. Everything works but as soon as I stop the service my data is gone. I'm using a named volume to persist data but probably doing something wrong. What is it?
Here's my setup:
# create my VM
docker-machine create dbvm
# set the right environment
eval $(docker-machine env dbvm)
Here's my docker-compose.yaml file:
version: '3'
services:
db:
image: postgres
environment:
- POSTGRES_USER=postgres
- POSTGRES_PASSWORD=postgres
- POSTGRES_DB=my_db
volumes:
- pgdata:/pgdata
ports:
- 5432:5432
pgadmin:
image: fenglc/pgadmin4
ports:
- 5050:5050
volumes:
- pgadmindata:/pgadmindata
volumes:
pgdata:
pgadmindata:
With docker-compose.yaml, I run:
docker stack deploy -c docker-compose.yaml dbstack
I can do everything on this setup, but if I run docker stack rm dbstack the data is gone after this, but the volumes still exist.
$ docker volume ls
DRIVER VOLUME NAME
local 0c15b0b22c6b850e8768c14045da166253424dda4df8d2e13df75fd54d833412
local 22bab81d9d1de0e07de97363596b096f944752eba617ff574a0ab525239227f5
local 6da6e29fb98ad0f66d7da6a75dc76066ce014b26ea43567c55ed318fda707105
local dbstack_pgadmindata
local dbstack_pgdata
What am I missing?
Unless you have it in some config not shown, I believe you need to map to the default data location inside the container e.g., pgdata:/var/lib/postgresql/data
#Idg is partially correct. postgres data lives at /var/lib/postgresql/data per the Docker Hub readme.
But for it to work in your named volume, you can't use a path on the left side, so correct value would be:
volumes:
- pgdata:/var/lib/postgresql/data
Then the postgres data will stay in that named volume, on the node it was created on.

How to compose an external data directory in PostgreSQL image within Docker?

I'm trying to create a couple of containers with Docker. One is a postgres:latest image and the other is ubuntu:latest image with postgresql-client installed.
I have an existing database cluster in my localhost that I've used before install docker, of course. Now I want to use that cluster in my PostgreSQL container. The path in my computer is /Users/Marco/Data.
I've created a volume too, with the command docker volume create --opt device=/Users/Marco/Data data_container to store the cluster in it.
Then tried to make a docker-compose.ymlfile with the following content:
version: '2'
services:
db:
image: postgres
environment:
- PGDATA=/var/lib/postgresql/data/
ports:
- "5432:5432"
volumes:
- data_container:/var/lib/postgresql/data/pgdata
shell:
image: ubuntu_pgsql
command: /bin/bash
tty: true
stdin_open: true
links:
- db
volumes:
data_container:
external: true
When I want to launch the containers with docker-compose up -d it shows me the following error:
ERROR: for db Cannot start service db: error while mounting volume '/var/lib/docker/volumes/data_container/_data': error while mounting volume with options: type='' device='/Users/Marco/Data' o='': no such device
ERROR: Encountered errors while bringing up the project.
What could be failing? Thanks.
If data container is a directory you should declare as:
volumes:
- ./data_container:/var/lib/postgresql/data/pgdata
If you used a data_container without ./ before, docker compose understand that is a file, not a directory.