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
Related
I am building a Flask application in Python. I'm using SQLAlchemy to connect to PostgreSQL.
In the flask application, I'm using this to connect SQLAlchemy to PostgreSQL
engine = create_engine('postgresql://postgres:[mypassword]#db:5432/employee-manager-db')
And this is my docker-compose.yml
version: '3.8'
services:
backend:
build:
context: .
dockerfile: Dockerfile
ports:
- 8000:8000
volumes:
- .:/app
links:
- db:db
depends_on:
- pgadmin
db:
image: postgres:14.5
restart: always
volumes:
- .dbdata:/var/lib/postgresql
hostname: postgres
environment:
POSTGRES_PASSWORD: [mypassword]
POSTGRES_DB: employee-manager-db
pgadmin:
image: 'dpage/pgadmin4'
restart: always
environment:
PGADMIN_DEFAULT_EMAIL: [myemail]
PGADMIN_DEFAULT_PASSWORD: [mypassword]
ports:
- "5050:80"
depends_on:
- db
I can do "docker build -t employee-manager ." to build the image. However, when I do "docker run -p 5000:5000 employee-manager" to run the image, I get an error saying
conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: could not translate host name "db" to address: Try again
Does anybody know how to fix this? Thank you so much for your help
Your containers are on different networks and that is why they don't see each other.
When you run docker-compose up, docker-compose creates a separate network and puts all the services defined inside docker-compose.yml on that network. You can see that with docker network ls.
When you run a container with docker run, it is attached to the default bridge network, which is isolated from other networks.
There are several ways to fix this, but this one will serve you in many other scenarios:
Run docker container ls and identify the name or ID of the db container that was started with docker-compose
Then run your container with:
# ID_or_name from the previous point
docker run -p 5000:5000 --network container:<ID_or_name> employee-manager
This attached the new container to the same network as your database container.
Other ways include creating a network manually and defining that network as default in the docker-compose.yml. Then you can use docker run --network <network_name> ... to attach other containers to that network.
docker run doesn't read any of the information in the docker-compose.yml file, and it doesn't see things like the Docker network that Compose automatically creates.
In your case you already have the service fully-defined in the docker-compose.yml file, so you can use Compose commands to build and restart it
docker-compose build
docker-compose up -d # will delete and recreate changed containers
(If the name of the image is important to you – maybe you're pushing to a registry – you can specify image: alongside build:. links: are obsolete and you should remove them. I'd also avoid replacing the image's content with volumes:, since this misses any setup or modification that's done in the Dockerfile and it means you're running untested code if you ever deploy the image without the mount.)
Can anyone tell me where I am going wrong. All I am trying to do is name a Mongo database using docker compose.
I have a docker compose file that looks like this:
version: "3"
services:
mongo-db:
image: mongo
environment:
- MONGO_INITDB_ROOT_USERNAME=admin
- MONGO_INITDB_ROOT_PASSWORD=password
- MONGO_INITDB_DATABASE=mydbname
ports:
- 27017:27017
volumes:
- mongo-db:/data/db
volumes:
mongo-db:
I run docker docker-compose -f docker-compose.yml up -d --build and it runs. I then open Robo 3T and connect to my container but every time I do the database is called test and not mydbname. Any ideas? TIA
The environment variables are only used to create a new database if no database already exists. You map a volume to /data/db and that volume probably contains an existing database named 'test'.
Find the volume using docker volume ls. It's called something like <directory name>_mongo-db. Then delete it using docker volume rm <volume name>.
Now Docker will create a new, empty volume and Mongo will create a new database when you start the container. And it'll use the values from the environment variables.
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
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.