Category: Docker

Docker Technology Fans

Starting and stopping App Engine instances with Docker

I’ve set up an App Engine project locally using Docker (on OSX), and have been running a server using the usual “gcloud preview app run app.yaml” command. From what I can tell, this keeps creating new images over and over again. After an hour or so of work I end up with something like 30 […]

kubernetes volume hostPath

I want to use kubernetes as my default development environment for that i set up the cluster locally with docker as explained in the official doc. I push my example to a github repository My set up steps after having a kubernetes cluster running were: * cd cluster_config/app && docker build –tag=k8s_php_dev . && cd […]

Key server times out while installing docker on Ubuntu 14.04

I am trying to install docker on Ubuntu 14.04, however, I can’t get beyond the first step documented here: $ sudo apt-key adv –keyserver hkp:// –recv-keys 58118E89F3A912897C070ADBF76221572C52609D Executing: gpg –ignore-time-conflict –no-options –no-default-keyring –homedir /tmp/tmp.VB8X4gv8Ty –no-auto-check-trustdb –trust-model always –keyring /etc/apt/trusted.gpg –primary-keyring /etc/apt/trusted.gpg –keyserver hkp:// –recv-keys 58118E89F3A912897C070ADBF76221572C52609D gpg: requesting key 2C52609D from hkp server gpg: […]

Firefox in a docker container accessible from selenium in another

I have a docker container running a rails app (let’s call it container A) that needs to do some scraping with watir webdriver using firefox as backend. I have firefox installed in another container (container B) and I want to be able to pass in container A something like: Selenium::WebDriver::Firefox::Binary.path= $DOCKER_RUN_CONTAINER_A So, each time watir […]

UDP Invalid Argument on Docker Swarm EC2

When sending UDP packets on EC2 with Docker I sometimes get this strange error (not all messages sent have an exception) which never happens on our inhouse cluster using OpenNebula. I have allowed all inbound/outbound traffic on every port on all my EC2 instances. Here is the exception: 2017-01-19 10:01:53,170 – ERROR: Exception caught for […]

Download all dependencies, plugin dependencies, compilers, etc. with Maven?

I’m baking a Docker image which runs a Maven task at runtime. It looks kind of like this: ADD pom.xml /srv ADD src /srv/src WORKDIR /srv RUN mvn dependencies:go-offline scala:testCompile At runtime, I’m running mvn gatling:execute to run a load testing utility. My POM looks like this: <project> <dependencies> <dependency> <groupId>io.gatling</groupId> <artifactId>gatling-core</artifactId> <version>${gatling.version}</version> </dependency> <dependency> […]

Can Windows Containers be hosted on linux?

I started to use docker about a month ago. I understand the basics, etc. But is this possible to run Windows Containers on Linux? The scenario is based on solution written in .NET (old net) and the Linux user that wants to run this with docker to write front-end based on back-end hosted in windows […]

Why is the Docker vfs storage backend not considered suitable for production?

The Docker vfs storage backend is in several places mentioned as not being a production backend (see for example this Docker GitHub issue comment by Michael Crosby). What makes it not suitable for production? Project Atomic’s description of storage backends says: The vfs backend is a very simple fallback that has no copy-on-write support. Each […]

How to use Postgresql container with existing data?

I am trying to set up postgresql container ( I have some data from current postgres instance. I copied it from /var/lib/postgresql/data and want to set it as a volume to postgres container. My part from docker-compose.yml file about postgres: db: image: postgres:9.4 ports: – 5432:5432 environment: POSTGRES_PASSWORD: postgres POSTGRES_USER: postgres PGDATA : /var/lib/postgresql/data volumes: […]

debootstrap inside a docker container

Here’s my problem: I want to build a chroot environment inside a docker container. The problem is that debootstrap cannot run, because it cannot mount proc in the chroot: W: Failure trying to run: chroot /var/chroot mount -t proc proc /proc (in the log the problem turns out to be: mount: permission denied) If I […]

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