This is a very important question and the answer is very simple, but fundamental: Run: create a new container of an image, and execute the container. You can create N clones of the same image. The command is: docker run IMAGE_ID and not docker run CONTAINER_ID Start: Launch a container previously stopped. For example, if … Read more
It’s a harder problem if you need to use SSH at build time. For example if you’re using git clone, or in my case pip and npm to download from a private repository. The solution I found is to add your keys using the –build-arg flag. Then you can use the new experimental –squash command … Read more
You need to commit the changes you make to the container and then run it. Try this: sudo docker pull ubuntu sudo docker run ubuntu apt-get install -y ping Then get the container id using this command: sudo docker ps -l Commit changes to the container: sudo docker commit <container_id> iman/ping Then run the container: … Read more
Containers: Containers are at the core of the other technologies listed here Docker: Docker is a popular implementation of the technology that allows applications to be bundled into a container. docker is a command-line tool to manage images, containers, volumes, and networks Docker Compose Docker Compose is the declarative version of the docker cli It … Read more
You can copy your crontab into an image, in order for the container launched from said image to run the job. See “Run a cron job with Docker” from Julien Boulay in his Ekito/docker-cron: Let’s create a new file called “hello-cron” to describe our job. # must be ended with a new line “LF” (Unix) … Read more
You need to add a dot, which means to use the Dockerfile in the local directory. For example: docker build -t mytag . It means you use the Dockerfile in the local directory, and if you use docker 1.5 you can specify a Dockerfile elsewhere. Extract from the help output from docker build: -f, –file=”” … Read more
TL;DR/Notice: If you experience a directory being created in place of the file you are trying to mount, you have probably failed to supply a valid and absolute path. This is a common mistake with a silent and confusing failure mode. File volumes are done this way in docker (absolute path example (can use env … Read more
You can commit your existing container (that is create a new image from container’s changes) and then run it with your new mounts. Example: $ docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 5a8f89adeead ubuntu:14.04 “/bin/bash” About a minute ago Exited (0) About a minute ago agitated_newton $ docker commit 5a8f89adeead newimagename … Read more
You cannot do this via Docker, but you can access the container’s un-exposed port from the host machine. If you have a container with something running on its port 8000, you can run wget http://container_ip:8000 To get the container’s IP address, run the 2 commands: docker ps docker inspect container_name | grep IPAddress Internally, Docker … Read more
docker-compose up $ docker-compose up -d –no-deps –build <service_name> –no-deps – Don’t start linked services. –build – Build images before starting containers.