Docker – an introduction

Docker is a virtualization tool, with the operating system environments and there running software in containers can be packed up and can be run on non-operating system environments.

The advantages of docker:

- Containers can be exchanged very easily with docker, This helps with the work on joint projects, If infrastructure needs to be angeapsst, only on the dev environment, then on the test environment, etc. So can run test using the appropriate environment, It therefore has a dynamic test environment, instead of a static

- performance advantages compared to virtual machines

- the containers make it easier, the development environment for software projects all participants quick and easy to make. This will make easier the onboarding and dependencies are avoided, as e.g.. a development server, work on all, which may not be altered but

- impertinent so finally environment simulates also distributed systems in development and testing and testing. This can error be earlier found and avoids. Who does not know that, the production system consists of multiple nodes behind a load balancer with master/slave database, but the dev/test/staging system has only a node without slave.

- Plattformunabhaengikeit: You can run on his MAC Windows applications in the container without any problems

Docker consists of several components: more…

Project: baby

The just completed project baby deals with the issues relating to the development of the own child:

  • How great my child be in x years
  • My child is like in x years
  • Is my child too hard or too thin
  • What dress size is wear it when?

The Web page is to help parents find out, When you need to buy what dress size, the approaching winter/summer home to have the appropriate.

Parents can thus einschätzne, If the child is too thin or too thick for your age/size/weight ratio.

The following technologies were used for the realization:

Symfony 3, Docker, MySQL, PHP, GIT, Google material design, Amazon AWS

Elasticsearch 5 Cluster with docker example

With the docker-compose.yml can be quickly built up a container-based environment with docker. The memory values for the Java VM are customizable (512MB) and for the docker image (1GB).

Cluster with 2 Nodes to operate, can see the elasticsearch2 comment out.

version: '2'
    container_name: elasticsearch1
      - bootstrap.memory_lock=true
      - "ES_JAVA_OPTS=-Xms512m -Xmx512m"
        soft: -1
        hard: -1
    mem_limit: 1g
      - esdata1:/usr/share/elasticsearch/data
      - 9200:9200
      - esnet
#  elasticsearch2:
#    image:
#    environment:
#      -
#      - bootstrap.memory_lock=true
#      - "ES_JAVA_OPTS=-Xms512m -Xmx512m"
#      - ""
#    ulimits:
#      memlock:
#        soft: -1
#        hard: -1
#    mem_limit: 1g
#    volumes:
#      - esdata2:/usr/share/elasticsearch/data
#    networks:
#      - esnet

    driver: local
#  esdata2:
#    driver: local


Docker 1.9: Error validating certificates

Error message:

Error running connection boilerplate: Error checking and/or regenerating the certs: There was an error validating certificates for host "": dial tcp i/o timeout You can attempt to regenerate them using 'docker-machine regenerate-certs name'. Be advised that this will trigger a Docker daemon restart which will stop running containers.

At the Fehlermledung, to new regenerate the TLS certificates, has helped me not, as recommended by others, Virtual box to update to the latest version, but only, the default image, to which docker himself erzegt generate together new certificates.

  1. For this opening virtual box and stop of the running virtual machine (default) for close -.> turn off
  2. Then it deletes the image in virtual box.
  3. Then you leave the image regenerate terminals with docker about running the docker