Node.js cluster module cannot use all the cpu cores when running inside docker container

When run Node.js cluster module on my physical machine, the os.cpus().length will get 4, but after put the app inside docker container then it returns 2! I generally know this is because that by default Golang will just run on one single core, that’s why here the cluster module only can see one single CPU […]

Short lived kubernetes container (/sidekick) in a pod (in a Replication Controller)

I have a ReplicationController containing two containers in a pod, the first is a long-living pod, the second does a few maintenance tasks when the RC starts up a POD. However as the second container is short lived, it stops itself when it finishes its start tasks. When Kuberbetes notices this, it kills off the […]

Persist Elastic Search Data in Docker Container

I have a working ES docker container running that I run like so docker run -p 80:9200 -p 9300:9300 –name es-loaded-with-data –privileged=true –restart=always es-loaded-with-data I loaded up ES with a bunch of test data and wanted to save it in that state so I followed up with docker commit containerid es-tester docker save es-tester > […]

Does using a Docker significantly improve the IO and processing speed?

I am running a java program that loops through a folder containing zip files, parses each file, does some processing and writes the result to a new file in another folder. I was suggested that I deploy this application on a Docker so that the job can be done more quickly. I should learn and […]

Docker – What is proper way to rebuild and push updated image to docker cloud?

Waht I’m doing now: Dockerfile: FROM python:3.5.1 ENV PYTHONUNBUFFERED 1 RUN mkdir /www WORKDIR /www ADD deps.txt /www/ RUN pip3 install -r deps.txt ADD . /www/ RUN chmod 0755 /www/ Build command: docker build -t my-djnago-app:latest . Tagging: docker tag my-djnago-app:latest lolorama/my-djnago-app-img:latest Pushing: docker push lolorama/my-djnago-app-img:latest After these steps repository image haven’t been updated. I […]

Docker build fail [duplicate]

This question already has an answer here: In Docker, apt-get install fails with “Failed to fetch … 404 Not Found” errors. Why? How can we get past it? 3 answers

Parsing a string to an array output from command line

I’m working on a new Symfony 2 project which will be a panel management for Docker containers. In this project, I’m executing some commands with the exec() PHP function. I’m trying to parse the output of the following command : docker create tutum/lamp:latest –name test 2>&1 When the command is a success I’m getting the […]

Docker and Java IDE integration

I’ll start by saying that I’m not a Java developer and also I’m not a Docker expert. In order to minimize the gap between frontend and backend (in this specific case, Java) developers I started to put some docker images in place with java and maven and after the build I start a docker container […]

How to sync code between container and host using docker-compose?

Until now, I have used a local LAMP stack to develop my web projects and deploy them manually to the server. For the next project I want to use docker and docker-compose to create a mariaDB, NGINX and a project container for easy developing and deploying. When developing I want my code directory on the […]

Are docker images portable across different linux flavours?

Are docker images portable across different linux flavours? Let’s say, if I have OEL based docker image with database installed in it, can I run this in boot2docker on a Mac?

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