Tutorial by Examples

Once you have a Dockerfile, you can build an image from it using docker build. The basic form of this command is: docker build -t image-name path If your Dockerfile isn't named Dockerfile, you can use the -f flag to give the name of the Dockerfile to build. docker build -t image-name -f Dockerfi...

FROM node:5 The FROM directive specifies an image to start from. Any valid image reference may be used. WORKDIR /usr/src/app The WORKDIR directive sets the current working directory inside the container, equivalent to running cd inside the container. (Note: RUN cd will not change the current ...

There are two Dockerfile directives to specify what command to run by default in built images. If you only specify CMD then docker will run that command using the default ENTRYPOINT, which is /bin/sh -c. You can override either or both the entrypoint and/or the command when you start up the built im...

EXPOSE <port> [<port>...] From Docker's documentation: The EXPOSE instruction informs Docker that the container listens on the specified network ports at runtime. EXPOSE does not make the ports of the container accessible to the host. To do that, you must use either the -p flag to ...

Suppose you have a Dockerfile ending with ENTRYPOINT [ "nethogs"] CMD ["wlan0"] if you build this image with a docker built -t inspector . launch the image built with such a Dockerfile with a command such as docker run -it --net=host --rm inspector ,nethogs will monitor the...

Locally created images can be pushed to Docker Hub or any other docker repo host, known as a registry. Use docker login to sign in to an existing docker hub account. docker login Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https...

Often when building a Docker image, the Dockerfile contains instructions that runs programs to fetch resources from the Internet (wget for example to pull a program binary build on GitHub for example). It is possible to instruct Docker to pass set set environment variables so that such programs per...