I have build a Docker image from a Docker file using the below command. $ docker build -t u12_core -f u12_core . When I am trying to rebuild it with the same command, it’s using the build cache like: Step 1 : FROM ubuntu:12.04 —> eb965dfb09d2 Step 2 : MAINTAINER Pavan Gupta <[email protected]> —> Using … Read more
This question is related to Should I be concerned about excess, non-running, Docker containers?. I’m wondering how to remove old containers. The docker rm 3e552code34a lets you remove a single one, but I have lots already. docker rm –help doesn’t give a selection option (like all, or by image name). Maybe there is a directory … Read more
I’m getting started working with Docker. I’m using the WordPress base image and docker-compose. I’m trying to ssh into one of the containers to inspect the files/directories that were created during the initial build. I tried to run docker-compose run containername ls -la, but that didn’t do anything. Even if it did, I’d rather have … Read more
Is there a command I can run to get the container’s IP address right from the host after a new container is created? Basically, once Docker creates the container, I want to roll my own code deployment and container configuration scripts. 5 53
How do I transfer a Docker image from one machine to another one without using a repository, no matter private or public? I create my own image in VirtualBox, and when it is finished I try to deploy to other machines to have real usage. Since it is based on my own based image (like … Read more
I am trying to build a backup and restore solution for the Docker containers that we work with. I have Docker base image that I have created, ubuntu:base, and do not want have to rebuild it each time with a Docker file to add files to it. I want to create a script that runs … Read more
In Dockerfiles there are two commands that look similar to me: CMD and ENTRYPOINT. But I guess that there is a (subtle?) difference between them – otherwise it would not make any sense to have two commands for the very same thing. The documentation states for CMD The main purpose of a CMD is to … Read more
I’m thinking of using Docker to build my dependencies on a Continuous Integration (CI) server, so that I don’t have to install all the runtimes and libraries on the agents themselves. To achieve this I would need to copy the build artifacts that are built inside the container back into the host. Is that possible? … Read more
What is the difference between the COPY and ADD commands in a Dockerfile, and when would I use one over the other? COPY <src> <dest> The COPY instruction will copy new files from <src> and add them to the container’s filesystem at path <dest> ADD <src> <dest> The ADD instruction will copy new files from … Read more
I keep rereading the Docker documentation to try to understand the difference between Docker and a full VM. How does it manage to provide a full filesystem, isolated networking environment, etc. without being as heavy? Why is deploying software to a Docker image (if that’s the right term) easier than simply deploying to a consistent … Read more
