Use of Supervisor in docker

I am not asking about the use of supervisor with dockers but just want to have my understanding validated. I understand that docker runs a single process when it is run. Also, supervisor is used when we need to run multiple process within the container. I have seen several examples where a container is started […]

Add a volume to Docker, but exclude a sub-folder

Supposed I have a Docker container and a folder on my host /hostFolder. Now if I want to add this folder to the Docker container as a volume, then I can do this either by using ADD in the Dockerfile or mounting it as a volume. So far, so good. Now /hostFolder contains a sub-folder, […]

Using SSH keys inside docker container

Alright, so essentially I have an app that executes various fun stuff with Git (like running git clone & git push) and I’m trying to docker-ize it. I’m running into an issue though where I need to be able to add an SSH key to the container for the container ‘user’ to use. Is there […]

How to update code from git to a Docker container

I have a Dockerfile trying to deploy a Django code to a container FROM ubuntu:latest MAINTAINER { myname } #RUN echo “deb $(lsb_release -sc) main universe” >> /etc/apt/sou$ RUN apt-get update RUN DEBIAN_FRONTEND=noninteractive apt-get install -y tar git curl dialog wget net-tools nano buil$ RUN DEBIAN_FRONTEND=noninteractive apt-get install -y python python-dev python-distribute python-p$ RUN […]

Using sudo inside a docker container

Normally, docker containers are run using the user root. I’d like to use a different user, which is no problem using docker’s USER directive. But this user should be able to use sudo inside the container. This command is missing. Here’s a simple Dockerfile for this purpose: FROM ubuntu:12.04 RUN useradd docker && echo “docker:docker” […]

Should I use Vagrant or Docker for creating an isolated environment? [closed]

I use Ubuntu for development and deployment and have a need for creating an isolated environment. I am considering either Vagrant or Docker for this purpose. What are the pros and cons, or how do these solutions compare? for Windows [closed]

I was reading a nice question about docker – answer has overview of docker implementation details. I was wondering if anything like this is possible to do on Windows platform. Do Windows alternatives for Docker exist? Is it theoretically possible to use other (Windows based) components to build it? Update1: Slightly related question (sandboxing): Is […]

Running migrations with Rails in a Docker container with multiple container instances

I’ve seen lots of examples of making Docker containers for Rails applications. Typically they run a rails server and have a CMD that runs migrations/setup then brings up the Rails server. If I’m spawning 5 of these containers at the same time, how does Rails handle multiple processes trying to initiate the migrations? I can […]

How to fix Docker's “Error pulling image…too many redirects” failures while pulling images from registry?

I am running Docker via CoreOS and Vagrant on OS X 10.10. When I run docker pull ubuntu in CoreOS, I got following errors: $ docker pull ubuntu Pulling repository ubuntu cc0067db4f11: Error pulling image (precise) from ubuntu, endpoint:, Get dial tcp: lookup cdn-registry-1.dcc0067db4f11: Error pulling image (precise) from ubuntu, Get dial […]

How to Keep Docker Container Running After Starting Services?

I’ve seen a bunch of tutorials that seem do the same thing I’m trying to do, but for some reason my Docker containers exit. Basically, I’m setting up a web-server and a few daemons inside a Docker container. I do the final parts of this through a bash script called that I run through […]

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