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.
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 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.
I am using Docker Compose to run several containers, including one with a Postgres image. I am attempting to add a volume to that container to persist my data across container builds. However, I am receiving an error when it tries to create a directory for this volume within the container.
I run:
docker-compose build
then
docker-compose up
And I receive the following error:
ERROR: for cxbenchmark_db_1 Cannot start service db: oci runtime error: container_linux.go:265: starting container process caused "process_linux.go:368: container init caused \"rootfs_linux.go:57: mounting \\"/var/lib/docker/volumes/69845a017b4465e9122852a75ca194db473df95fa218658b8a60fb56eba9be9e/_data\\" to rootfs \\"/var/lib/docker/overlay2/627956d63fb0480448079577a83b0b54f83866fdf31136b7c669541c3f672355/merged\\" at \\"/var/lib/docker/overlay2/627956d63fb0480448079577a83b0b54f83866fdf31136b7c669541c3f672355/merged/var/lib/postgresql/data\\" caused \\"mkdir /var/lib/docker/overlay2/627956d63fb0480448079577a83b0b54f83866fdf31136b7c669541c3f672355/merged/var/lib/postgresql/data: permission denied\\"\""
My full docker-compose.yml looks like this (note the service called db where the volume is defined):
version: '3'
services:
nginx:
image: nginx:latest
ports:
- 80:8000
volumes:
- ./src:/src
- ./config/nginx:/etc/nginx/conf.d
- ./src/static:/static
depends_on:
- web
web:
build: .
command: bash -c "python manage.py makemigrations && python manage.py migrate && gunicorn cx_benchmark.wsgi -b 0.0.0.0:8000"
depends_on:
- db
volumes:
- ./src:/src
- ./src/static:/static
expose:
- 8000
db:
image: postgres:latest
volumes:
- /private/var/lib/postgresql:/var/lib/postgresql
ports:
- 5432:5432
Any ideas for how to solve?
The error you are seeing is not a problem (necessarily) with the explicit volume bind mount in your compose file, but rather with the VOLUME declaration in the main postgres official Docker image Dockerfile:
VOLUME /var/lib/postgresql/data
Since you haven't provided a mount-point for this directory (but rather the parent), the docker engine is creating a local volume and then trying to mount that volume into your already bind-mounted location and getting a permissions error.
For clarity, here is the volume the docker engine created for you:
/var/lib/docker/volumes/69845a017b4465e9122852a75ca194db473df95fa218658b8a60fb56eba9be9e/_data
And here is the directory location at which it is trying to bind mount that dir; on top of your bind mount from /private/var/lib/postgresql:
mkdir /var/lib/docker/overlay2/627956d63fb0480448079577a83b0b54f83866fdf31136b7c669541c3f672355/merged/var/lib/postgresql/data: permission denied
Now, I think the reason this is failing is that you may have turned on user namespaces in your Docker engine ("userns-remap" flag/setting) such that the container doesn't have permissions to create a directory in that root-owned location on your host. Barring that, the only other option is that the postgres container is starting as a non-root user, but I don't see anything in your compose file or the official Dockerfile for the latest release that uses the USER directive.
As an aside, since you are ending up with double-volumes because your bind mount doesn't match the VOLUME specifier in the postgres Dockerfile, you could change your compose file to mount to /var/lib/postgresql/data and get around that extra volume being created. Especially if you expect your DB data to end up in /private/var/lib/postgresql, as it may be surprising to find it isn't there, but rather in the /var/lib/docker/volumes/.. location.
I'm trying to persist postgres data in a docker container so that as soon as you docker-compose down and docker-compose up -d you don't lose data from your previous session. I haven't been able to make it do much of anything - pulling the container down and back up again routinely deletes the data.
Here's my current docker-compose.yml:
version: '2'
services:
api:
build: .
ports:
- '8245:8245'
volumes:
- .:/home/app/api
- /home/app/api/node_modules
- /home/app/api/public/src/bower_components
links:
- db
db:
build: ./database
env_file: .env
ports:
- '8246:5432'
volumes_from:
- dbdata
dbdata:
image: "postgres:9.5.2"
volumes:
- /var/lib/postgresql/data
Help?
According to the Dockment of Docker Compose, when you write something like:
volumes:
- /var/lib/postgresql/data
It creates a new docker volume and map it to /var/lib/postgresql/data inside the container.
Therefore, each time you run docker-compose up and docker-compose down, it creates new volume. You can confirm the behavior with docker volume ls.
To avoid it, you have two options:
(A) Map host directory into container
You can map directory of host into container using <HOST_PATH>:<CONTAINER_PATH>.
volumes:
- /path/to/your/host/directory:/var/lib/postgresql/data
The data of postgresql will be saved into /path/to/your/host/directory of the container host.
(B) Use external container
docker-compose has an option of external container.
When it is set to true, it won't always create volume.
Here's an example.
version: '2'
services:
dbdata:
image: postgres:9.5.2
volumes:
- mypostgresdb:/var/lib/postgresql/data
volumes:
mypostgresdb:
external: true
With external: true, docker-compose won't create the mypostgredb volume, so you have to create it by your own using following command:
docker volume create --name=mypostgredb
The data of postgresql will be saved into docker volume named mypostgredb. Read reference for more detail.