All about the Docker!

Commands

$ docker ps	Looks at the current running Processes on Docker.
$ docker ps -a	Looks at the ALL Processes on Docker.
$ docker version	Looks at the version of Client/Server of Docker.
$ docker info	Looks at the Detailed information of Docker status.
$ docker images	Looks at the current Images that are on the Docker.
$ docker run hello-world	Install hello-world image from docker daemon and run img.
$ docker rm [Container_ID]	Remove Exited Image from docker.
$ docker rm -f [Container_ID]	Forcefully Remove Image from docker.
$ docker start [Container_ID]	Start the Existing Docker Img.
$ docker attach [Container_ID]	Attach onto a currently running docker container.
$ docker cp [src] [contnr_name/id]:[dest]	Copy src(folder or file) into destination in container.
$ docker rmi [Image_ID]	Remove Image that is not in Container.
$ docker build [options] PATH \| URL	Build docker image based on Dockerfile at PATH\|URL. Common option is -t to specify repository name of created image.
$ docker run -it ubuntu bash	Install ubuntu:latest Image and run in Bash shell.
$ exit	Exit out of running shell.

Click an instruction link for more details.

FROM <image>	Sets the image where instructions are to be ran. Must be at top of Dockerfile.
RUN <command> [flags] [param,...]	Executes commands. Creates and commits new layer, so subsequent instructions work with newly committed image.
CMD <command> [flags] [param,...]	Sets default command, which will be executed when the container is run without specifying a command. Only one will work per Dockerfile, last one used. If running with command specified, CMD will be overridden and ignored.
ENTRYPOINT <command> [flags] [param,...]	Same as CMD, but will not be overridden when running with command specified.
ENV <key>=<value>,...	Set environment variables for all subsequent instructions.
COPY <src>... <dest>	Copies local files and directories to container at specified (absolute) location. Can use multiple sources, and can include wildcards.
ADD <src>... <dest>	Same as COPY, but sources may be URL, and will unpack sources if compressed.
EXPOSE <port> [<port>...]	Container will listen to specified ports at runtime. To make ports accessable to the host, use -p or -P to publish exposed ports.
WORKDIR /path/to/workdir	Set working directory for all following RUN, CMD, ENTRYPOINT, COPY, ADD instructions. Creates directory if it doesn't exist. Can use previously set ENV variables, but only those set in Dockerfile.