Backup a running Docker container?

Is it possible to backup a running Docker container? Is the export command suitable for doing that?

How do I make a comment in a Dockerfile?

I am writing a Dockerfile and I want to know if there is any way to make comments in this file? Does docker have a comment option that takes the rest of a line and ignores it?

Start container with multiple network interfaces

With 1.9, is there a way to start a container directly with two or more network interfaces? You can do it after the container is started with “docker network connect”, but it means the process is already running and might miss the creation of the new one.

Auto-reloading of code changes with Django development in Docker with Gunicorn

I’m using a Docker container for Django development, and the container runs Gunicorn with Nginx. I’d like code changes to auto-load, but the only way I can get them to load is by rebuilding with docker-compose (docker-compose build). The problem with “build” is that it re-runs all my pip installs. I’m using the Gunicorn –reload […]

How to link docker containers on build?

I linked my app container to postgres on run: docker run –link postgres:postgres someproject/develop and it worked fine. But I realized that I need to install some stuff to database with django command before run. So I need linking while build. How can I do that? docker build -h doesn’t have –link option.

How to edit Docker container files from the host?

Now that I found a way to expose host files to the container (-v option) I would like to do kind of the opposite: How can I edit files from a running container with a host editor? sshfs could probably do the job but since a running container is already some kind of host directory […]

How to include files outside of Docker's build context?

How can I include files from outside of Docker’s build context using the “ADD” command in the Docker file? From the Docker documentation: The path must be inside the context of the build; you cannot ADD ../something/something, because the first step of a docker build is to send the context directory (and subdirectories) to the […]

How do I model a PostgreSQL failover cluster with Docker/Kubernetes?

I’m still wrapping my head around Kubernetes and how that’s supposed to work. Currently, I’m struggling to understand how to model something like a PostgreSQL cluster with streaming replication, scaling out and automatic failover/failback (pgpool-II, repmgr, pick your poison). My main problem with the approach is the dual nature of a PostgreSQL instance, configuration-wise — […]

How to name Dockerfiles

I’m a bit dense on how to name Dockerfiles. The examples on GitHub just seem to be called Dockerfile. Do I give them a name and extension; if so what? Or just call them Docker file? Many thanks, LRP

What is the difference between Cloud Foundry and Docker?

I am a Java developer. We use Weblogic to host our applications. I have been told to look into replacing weblogic with an opensource alternative. We are planning use with SpringBoot. We are also looking at Docker/Cloud Foundry. However Docker/Cloud Foundry is new territory for me. Can someone please tell me the difference between Cloud […]

Docker will be the best open platform for developers and sysadmins to build, ship, and run distributed applications.