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.
Related
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.
I try to run a Postgres Docker container in an Azure Web App.
When i try to mount a volume to the Data folder, i get the error: FATAL: data directory "/var/lib/postgresql/data" has wrong ownership
my Compose script:
version: "3"
services:
db:
image: postgres:11.2
environment:
- POSTGRES_USER=test
- POSTGRES_PASSWORD=test
- POSTGRES_DB=test
volumes:
- ${WEBAPP_STORAGE_HOME}/data:/var/lib/postgresql/data
ports:
- "5433:5432"
Docker host is set to linux.
how can i get around this issue?
(if i dont, the data is lost every restart / container update)
For this issue, you can take a look at the Dockerfile of the image postgres. There is a step that changes the ownership of the directory /var/lib/postgresql with the command:
chown -R postgres:postgres /var/lib/postgresql
But when you use the persistent storage in Azure Web App, you cannot change the permission of it. So it causes the error:
FATAL: data directory "/var/lib/postgresql/data" has wrong ownership
See more details about the limitation here.
I'm trying to run a docker image with PostgreSQL that has a volume configured for persisting data.
docker-compose.yml
version: '3.1'
services:
db:
image: postgres
restart: always
volumes:
- ./data:/var/lib/postgresql/data
environment:
POSTGRES_PASSWORD: example
When I start the container I see the output
fixing permissions on existing directory /var/lib/postgresql/data ... ok
and the data folder is no longer readable for me.
If I elevate myself and access the data directory I can see that the files are there. Furthermore, the command ls -ld data gives me
drwx------ 19 systemd-coredump root 4096 May 17 16:22 data
I can manually set the directory permission with sudo chmod 755 data, but that only works until I restart the container.
Why does this happen, and how can I fix it?
The other answer indeed points to the root cause of the problem, however the help page it points to does not contain a solution. Here is what I came up with to make this work for me:
start the container using your normal docker-compose file, this creates the directory with the hardcoded uid:gid (999:999)
version: '3.7'
services:
db:
image: postgres
container_name: postgres
volumes:
- ./data:/var/lib/postgresql/data
environment:
POSTGRES_USER: fake_database_user
POSTGRES_PASSWORD: fake_database_PASSWORD
stop the container and manually change the ownership to uid:gid you want (I'll use 1000:1000 for this example
$ docker stop postgres
$ sudo chown -R 1000:1000 ./data
Edit your docker file to add your desired uid:gid and start it up again using docker-compose (notice the user:)
version: '3.7'
services:
db:
image: postgres
container_name: postgres
volumes:
- ./data:/var/lib/postgresql/data
user: 1000:1000
environment:
POSTGRES_USER: fake_database_user
POSTGRES_PASSWORD: fake_database_password
The reason you can't just use user: from the start is that if the image runs as a different user it fails to create the data files.
On the image documentation page, it does mention a solution to add a volume to expose the /etc/passwd file as read-only in the image when providing --user option, however, that did not work for me with the latest image, as I was getting the following error. In fact none of the three proposed solutions worked for me.
initdb: error: could not change permissions of directory "/var/lib/postgresql/data": Operation not permitted
This is because of what is written in the dockerfile of the postgres image.
From line 15 to 18, you'll see that the group 999 and the user 999 are used. I'm guessing that in your host, they map respectively to systemd-coredump and root.
You need to know that whenever you use a user/group in an image, if the uid/gid exist in your host, then it will be mapped to it.
You can read the documentation on the docker hub from the postgres image here. There is a section Arbitrary --user Notes that explain how it works in the context of this image.
An easier and permanent solution would be as follows:
Add these lines to ~/.bashrc:
export UID=$(id -u)
export GID=$(id -g)
Reload your shell:
$ source ~/.bashrc
Modify your docker-compose.yml as follows:
version: "3.7"
services:
db:
image: postgres
volumes:
- ./tmp/db:/var/lib/postgresql/data
user: "${UID}:${GID}"
...
Source
here's what i did:
services:
postgres:
image: postgres:15.1
restart: always
environment:
- POSTGRES_USER=my_user
- POSTGRES_PASSWORD=my_user
- POSTGRES_DB=my_user
user: root
ports:
- "5432:5432"
volumes:
- /home/my_user/volumes/postgres/data:/var/lib/postgresql/data
- /home/my_user/volumes/postgres/config:/etc/postgresql
postgres_setup:
image: postgres:15.1
user: root
volumes:
- /home/my_user/volumes/postgres/data:/var/lib/postgresql/data
- /home/my_user/volumes/postgres/config:/etc/postgresql
entrypoint: [ "bash", "-c", "chmod 750 -R /var/lib/postgresql/data && chmod 750 -R /etc/postgresql"]
depends_on:
- postgres
pgadmin4:
image: dpage/pgadmin4
restart: always
environment:
- PGADMIN_DEFAULT_EMAIL=my_user#admin.com
- PGADMIN_DEFAULT_PASSWORD=my_user
- PGADMIN_LISTEN_ADDRESS=0.0.0.0
user: root
ports:
- "5050:80"
volumes:
- /home/my_user/volumes/pgadmin/data:/var/lib/pgadmin
depends_on:
- postgres_setup
the postgres_setup container just changes permissions and then shuts down
I have been struggling with a similar issue and the answer hit me when trying to work around postgres (static uid per container, configured or 70 by default on alpine, 999 on standard image), and docker limitations (no uid translation of volumes).
The answer is to utilize Linux ACL without any changes to docker-compose.yml user - just keep the default internal container user id.
mkdir -p ./data
sudo setfacl -m u:$(id -u):rwx -R ./data/
docker-compose up -d
or
docker-compose up -d
sudo setfacl -m u:$(id -u):rwx -R ./data/
The order of creating data volume's directory does not matter and as long as ACL is set after it was created, you as a user will be able to access it recursively. You can of course add additional permissions.
To check who has access to data folder simply run:
getfacl ./data
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
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.