The relation between “docker/swarm” and “docker/swarmkit”

I am already familiar with docker/swarm, but find there occurs a “new” project: docker/swarmkit. But unfortunately, after reading the README, I still can’t figure out what is the function of docker/swarmkit. Could anyoone help to elaborate the relations between docker/swarm and docker/swarmkit? Why is docker/swarmkit born?

Run multiple servers from a docker image

I have three express servers written on nodejs. These servers are serving different purposes and hence running on different ports. Eg: app1.js on 8000, app2.js on 5000 and app3.js on 5432. I want to create a docker image using a docker file and run all these servers. Can we do so? If so, how can […]

Dockerfile FROM Instruction

The Dockerfile reference says the following about the FROM instruction: FROM can appear multiple times within a single Dockerfile in order to create multiple images. Simply make a note of the last image ID output by the commit before each new FROM command. I don’t understand what they mean by note the last image ID […]

Docker Images Hierarchy

I would like to check what image is a parent of my given Docker image (FROM with image layer it was created). How can I retrieve this information? I tried do that through docker images -t but this flag is deprecated in new Docker versions. Is there any reliable source of such an info?

Mongorestore in a Dockerfile

I want to create a Docker image that starts a mongo server and automatically restores from a previous mongodump on startup. Here is my Dockerfile for the image: FROM mongo COPY dump /home/dump CMD mongorestore /home/dump When I run this, I run into this error: Failed: error connecting to db server: no reachable servers Is […]

Integrating Docker-Machine with Amazon EC2

I am reading this article which shows me how I can configure my docker VM on top of amazon ec2 https://docs.docker.com/machine/drivers/aws/ I got to the step docker-machine create –driver amazonec2 aws01 but now I get an error Error with pre-create check: “unable to find a subnet in the zone: us-east-1a” I googled and found this […]

Why are docker layer IDs now hidden with the new storage model?

Docker 1.10 introduced a new content adressable storage model. So now a layer ID is created as a hash from its content. This way layers with the same content should be reused. This sounds nice, but why the heck is this ID hidden from us now? I’ve done some simple tests to find out, if […]

How can I have shared assets (pictures, text documents, etc) between my Docker container and host system?

I have a Docker container and I am trying to make it so that all of the files in /var/www/ on the container will be saved on the host system at a location (/home/me), and vise-versa. Is it possible to have this shared space between the two? Would you accomplish this with mount points, or […]

Random container names when building from the same docker-compose file

I have the following docker-compose.yml file: version: ‘2’ services: php-apache: image: reynierpm/php55-dev ports: – “80:80” environment: PHP_ERROR_REPORTING: ‘E_ALL & ~E_DEPRECATED & ~E_NOTICE’ volumes: – ~/data:/data Each time I run the following command docker-compose up -d it creates a container with the same name all the time as for example php55devwork_php-apache_1 which is the folder where […]

Error Docker deployment in Amazon EC2 – Docker container quit unexpectedly

I am trying to deploy a Dockerfile and a Dockerrun.aws.json in Amazon EC2. I am able to successfully create the Docker container but after that, the instance is crashing. I dont know why the Docker container is quitting unexpectedly or how to fix it. Log: Step 36 : RUN service apache2 stop && service apache2 […]

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