Using docker and docker-compose¶

This is not a comprehensive guide on how to use docker and all of it’s features but will give you common used commands.

List Running Containers¶

$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

Build containers:¶

docker-compose build

To build a specific container

docker-compose build NAME

e.g. docker-compose build nginx

Start a container¶

$ docker-compose up

Start in background: docker-compose up -d Start specific container: docker-compose up -d NAME

Stop all containers¶

docker-compose stop

Stop and delete containers¶

This will delete the container but not the built images. This is usually used for puging database entries.

docker-compose down

Delete all images from machine¶

This will delete all images, containers, volumes and networks created. Usually used to clean environment.

docker system prune -a

Work from inside the container¶

You can work from inside the container. This is useful to check if the correct versions are being used.

 ~/qlf/docs$ docker ps
 CONTAINER ID        IMAGE                                                    COMMAND                  CREATED             STATUS              PORTS                                            NAMES
 46d12dd9e9ef        qlf_nginx                                                "nginx -g 'daemon of…"   24 minutes ago      Up 24 minutes       80/tcp, 0.0.0.0:80->8080/tcp                     qlf_nginx_1
 29ff55378420        linea/qlf:BACK6f9165e25b07d92782cb2a7ab341ea013da99ac3   "/usr/bin/tini -- ./…"   24 minutes ago      Up 24 minutes       0.0.0.0:5006->5006/tcp, 0.0.0.0:8000->8000/tcp   qlf_app_1
 f1d141fa6f50        postgres                                                 "docker-entrypoint.s…"   24 minutes ago      Up 24 minutes       5432/tcp                                         qlf_db_1
 3ae98699a50f        redis                                                    "docker-entrypoint.s…"   24 minutes ago      Up 24 minutes       6379/tcp                                         qlf_redis_1
 ~/qlf/docs$ docker exec -it qlf_app_1 bash
 root@29ff55378420:/app#

Restart Backend¶

After the changes are made in the backend run ./restartBackend to restart the containers with the latest code if it doesn’t do it automatically.

~/qlf$ ./restartBackend.sh
Stopping qlf_app_1 ... done
Recreating 9c38c1b6436a_qlf_db_1    ... done
Recreating ac0c3d755824_qlf_redis_1 ... done
Recreating qlf_app_1                ... done
Recreating qlf_nginx_1              ... done

FAQ¶

If you are using linux and got this error:

ubuntu ~/docker $ docker-compose up -d
ERROR: Couldn't connect to Docker daemon at http+docker://localunixsocket - is it running?

If it's at a non-standard location, specify the URL with the DOCKER_HOST environment variable.

Add your current user to docker group:

sudo usermod -aG docker $USER

And make sure to log out of your terminal prompt and log back in in order for usermod changes take effect.

If port is already allocated

For instance,

ERROR: for db  Cannot start service db: driver failed programming external connectivity on endpoint backend_db_1 (4d2adece087f3df9a3e34695246a22db6639e63e8b8054e3cb03f1209252b88d): Bind for 0.0.0.0:5433 failed: port is already allocated

Run docker ps to check for old containers up and running on your machine.

$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                    NAMES
d92b7eb3583e        qlf_nginx           "nginx -g 'daemon of…"   5 minutes ago       Up 5 minutes        80/tcp, 7070/tcp, 0.0.0.0:80->8080/tcp   qlf_nginx_1
7622ffe8f2a9        qlf_backend         "/usr/bin/tini -- ./…"   5 minutes ago       Up 5 minutes        8000/tcp                                 qlf_backend_1
1c69cb7e5aff        redis               "docker-entrypoint.s…"   5 minutes ago       Up 5 minutes        6379/tcp                                 qlf_redis_1
709cc22755bc        postgres            "docker-entrypoint.s…"   5 minutes ago       Up 5 minutes        5432/tcp                                 qlf_db_1

You can stop it individually by name, for example: docker stop qlf_qlf_1