RUN is an image build step, the state of the container after a RUN command will be committed to the container image. A Dockerfile can have many RUN steps that layer on top of one another to build the image. CMD is the command the container executes by default when you launch the built image. … Read more
You need to tag your image correctly first with your registryhost: docker tag [OPTIONS] IMAGE[:TAG] [REGISTRYHOST/][USERNAME/]NAME[:TAG] Then docker push using that same tag. docker push NAME[:TAG] Example: docker tag 518a41981a6a myRegistry.com/myImage docker push myRegistry.com/myImage
In October 2014 the Docker team introduced docker exec command: https://docs.docker.com/engine/reference/commandline/exec/ So now you can run any command in a running container just knowing its ID (or name): docker exec -it <container_id_or_name> echo “Hello from container!” Note that exec command works only on already running container. If the container is currently stopped, you need to … Read more
Dockerfile A Dockerfile is a simple text file that contains the commands a user could call to assemble an image. Example, Dockerfile FROM ubuntu:latest MAINTAINER john doe RUN apt-get update RUN apt-get install -y python python-pip wget RUN pip install Flask ADD hello.py /home/hello.py WORKDIR /home Docker Compose Docker Compose is a tool for defining … Read more
You can use # at the beginning of a line to start a comment (whitespaces before # are allowed): # do some stuff RUN apt-get update \ # install some packages && apt-get install -y cron #‘s in the middle of a string are passed to the command itself, e.g.: RUN echo ‘we are running … Read more
For all platforms Docker v 20.10 and above (since December 14th 2020) On Linux, add –add-host=host.docker.internal:host-gateway to your Docker command to enable this feature. (See below for Docker Compose configuration.) Use your internal IP address or connect to the special DNS name host.docker.internal which will resolve to the internal IP address used by the host. … Read more
I got confused by this also. There are two commands relevant here: docker run # Run a command in a **new** container docker start # Start one or more stopped containers
After evaluating the answers and studying the topic I’d like to summarize. The Docker way to upgrade containers seems to be the following: Application containers should not store application data. This way you can replace app container with its newer version at any time by executing something like this: docker pull mysql docker stop my-mysql-container … Read more
You can use Environment Replacement in your Dockerfile as follows: ENV PATH=”${PATH}:/opt/gtk/bin”
With docker 1.3, there is a new command docker exec. This allows you to enter a running container: docker exec -it [container-id] bash Note: this assumes bash is installed on your container. You may run sh or whatever interactive shell is installed on the container.