/docker-notes

Connecting to a Container

docker container run -it diamol/base

Get details of all running containers:

docker container ls

List the process running in the container:

docker container top <container-id>

Cleanup Commands

Remove all containers:

docker container rm -f $(docker container ls -aq)

Reclaim disk space:

docker image rm -f $(docker image ls -f reference='diamol/*' -q)

Run a Website in a Container

docker container run --detach --publish 8088:80 diamol/ch02-hello-diamol-web

View CPU, memory, network and disk usuage:

docker container stats <image-id-from-pervious-command>

Use an Existing Image

Pull the image:

docker image pull diamol/ch03-web-ping

Run a container:

docker container run -d --name web-ping diamol/ch03-web-ping

View the Logs

docker container logs web-ping

docker container logs --tail 4 todo-dev

Overriding Environment Variables

Use environment variable:

docker container run --env TARGET=google.com diamol/ch03-web-ping

Disk Space Usage

docker system df

Build an Image

From the project root folder, run:

docker image build --tag web-ping .

View Images

docker image ls

Images starting with w:

docker image ls 'w*'

Configuration settings can be applied with environment variables:

docker container run -e TARGET=docker.com -e INTERVAL=5000 web-ping

Check History of Image

docker image history web-ping

Tag an Image

docker image build -t web-ping:v2 .

Optimizing Dockerfile

Order instructions based on the change frequency. Instructions that are unlikely to change are at the start of the Dockerfile.

FROM diamol/node

CMD ["node", "/web-ping/app.js"]

ENV TARGET="blog.sixeyed.com" \
    METHOD="HEAD" \
    INTERVAL="3000" 

WORKDIR /web-ping
COPY app.js .

Rebuild the optimized image:

docker image build -t web-ping:v3 .

Scale Up

Run three instances of iotd:

docker-compose up -d --scale iotd=3