Docker

Containerization has been around for awhile. Docker helped make it easy to use. My collection of things for Docker are stored here for reference in the future.

Formatting

Using docker ps --format '{{.ID}}' will output all the IDs of the output from the ps command. Other fields available are:

.ID
.Image
.Command
.CreatedAt
.RunningFor
.Ports
.Status
.Size
.Names
.Labels
.Label
.Mounts
.Networks

Stop or/and Removing

To stop containers allows for halting a running container. If you did not use the --rm command, it still remains in the list of containers under management by Docker. To see this list, you need to use the docker ps -a command.

Thus to stop and remove a docker container, you really have two options:

1. start the container with --rm to remove the container automatically
2. use a script to stop and remove the container in one go

Here is the simple script I use to stop and remove containers in one go:

for id in $(docker ps --format '{{.ID}}')
do
  docker stop $id
  docker rm $id
done

docker-compose.yml

plain simple template

https://docs.docker.com/compose/compose-file/compose-file-v3/

version: "3.9"
services:
  webapp:
    build:
      context: ./dir
      dockerfile: Dockerfile-alternate
      args:
        buildno: 1
      labels:
        - "com.example.description=Accounting webapp"
        - "com.example.department=Finance"
        - "com.example.label-with-empty-value"
    depends_on:
      - db
      - redis
  redis:
    image: redis
  db:
    image: postgres