Does Docker support SO_REUSEPORT for kernel 3.9+?

Does docker support binding containers to public port on host using SO_REUSEPORT option ? Usecase: We have haproxy running in docker and it binds to port 80 on host. We want to do automated A/B deploy for new version of proxy on the same host (Note proxy is running as docker container). One way to […]

Access to a docker container on Heroku

I am using Heroku with Docker. I need to upload files in /public/pictures and I want to do it via sftp or scp. I tried to expose the port 22 and access to the container with this comment : ssh It do nothing. Is there a way to do it? Is there a better […]

Guidance needed – how to track nginx-docker-rails performance issue

My Rails application is deployed on Amazon elastic beanstalk using Docker. Web requests flow into an nginx web server that forwards them to the thin rails server residing in docker. Somewhere along the way there’s a bottleneck. Once every 50 requests (or so) I see nginx reports serving time which is x40 higher than the […]

Sharing directories in a Docker container both with a Dockerfile and after the container is running

Sharing data between a running docker container and my host (on AWS) seems overly complicated. From the docker documentation it seems as if I need to specify volumes when I start the container. I found this: But this watches recursively to copy only from the host machine to the docker container I’m looking for […]

Scala SBT set dockerRepository “Repository for publishing is not specified”

I’m trying to publish a scala build to a docker registry with the following command : ./sbt “; set dockerRepository := Some(\”registryname/project\”); docker:publish” I am specifying the dockerRepository but when running the command it is throwing the following error : [error] You cannot push a “root” repository. Please rename your repository to <user>/<repo> (ex: <user>/example) […]

How to monitor for Java Exceptions externally?

I am trying to implement a real time metrics system which monitors java applications running in a docker environment. I have a spring boot web application which works as the external client that polls spring boot actuator endpoints of each of the applications in the docker environment to return metrics which are then sent to […]

Docker volume performance degradation

I was running some performance benchmarks using fio to compare the performance of a Docker volume (created using the -v option) against the performance of a volume mounted on the host machine. I am using the following command to run IO on both the volumes: fio –name=seqwrite –ioengine=libaio –iodepth=1 –rw=write –bs=8M –direct=1 –size=1024M –numjobs=24 –runtime=300 […]

Ansible ignores remote_user switch

I would like to provision a docker image using ansible. For this I have a Dockerfile like this … # import provisioning config ADD provisioning /tmp/provisioning # provisioning RUN ansible-playbook -i /tmp/provisioning/inventory /tmp/provisioning/playbook.yml -c local … Since the playbook is executed during docker’s image-building process it is executed as root inside the container. Now there […]

Docker 5 beta4 kestrel doesn't keep container running

I was playing with 5 beta 4 docker image. I am running the container with the entrypoint dnx /app kestrel. The Dockerfile is standard from tutorials: FROM microsoft/aspnet:1.0.0-beta4 MAINTAINER “xxxx” <xxxx> #this contains project.json etc COPY ./app /app WORKDIR /app RUN [“dnu”, “restore”] EXPOSE 5004 ENTRYPOINT [“dnx”, “/app”, “kestrel”] The container starts and exits […]

gcloud ping attempt failure with performing a 'docker push'

I ran the following command gcloud preview docker push And I got the following error. Does anyone know how I fix that or what it means? All I was doing was following the standard examples just to learn how it works… Thanks 🙂 FATA[0010] Error: v1 ping attempt failed with error: Get dial […]

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