Docker commands
| List containers | dk container ls -a dk ps -a |
| Start container with port forwarding | dk run --name dvtools -ti -d -p 8080:80 <imge> --name dvtools |
| Tag an image | dk image tag <imgid> dvtools:latest dvtools:v2 |
| Tag image for Repo | dk image <img> dennysv/dvtools:latest |
Quick commands for Images
| alias | alias dk='docker' |
| Remove all images | dk image prune -a |
| Build Image and tag | dk build . -t dvtools:v1 |
| Check an image layers | dk inspect <image ID> |
| History of image creation | dk image history <image> |
| List Docker images | dk image ls |
| Delete image | dk image rm <contaier> rmi |
| Ignore files during build | .dockerignore |
| Search official image | dk search --filter "is-official=true" ubuntu |
DockerFile Quick reference
| COPY | Copy files in to the image |
| Volume | Creates a Mountpoint as defined |
| ENTRYPOINT | The executable that runs when container is run. It accepts input parameters, or takes from CMD |
| EXPOSE | Defines ports to be published. |
| CMD | Command to execute at start, will ignore input parameters. If ENTRYPOINT is defined CMD arguments are passed as arguments. Only 1 command allowed, only last one will take effect. |
| ENV | Variables to be defined in the container. |
| RUN | A command to be run in a new layer of Image being build |
| FROM | Define base image from which image is built. This is first instruction. |
| WORKDIR | Working Directory of container |
Difference between CMD and ENTRYPOINT
Both Entry point and CMD execute instructions at start of container, however behaviour differ.
CMD : When only CMD is specified, it executes command and will ignore any parameters passed.
ENTRYPOINT: Defines command to execute at start, then inputs are passed as arguments. If CMD also specified, ENTRYPOINT will treat CMD as arguments than commands.
Use of CMD is preferred unless there is requirement to accept arguments for container run.