Docker: Copying files from Docker container to host

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

From inside of a Docker container, how do I connect to the localhost of the machine?

So I have a Nginx running inside a docker container, I have a mysql running on localhost, I want to connect to the MySql from within my Nginx. The MySql is running on localhost and not exposing a port to the outside world, so its bound on localhost, not bound on the ip address of … Read more

What is the difference between the ‘COPY’ and ‘ADD’ commands in a Dockerfile?

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

How is Docker different from a virtual machine?

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