Docker Basics: Docker Compose

Create, configure, and run a multi-container application using Docker Compose and this introductory tutorial.

Docker Compose is a tool that allows you to run multi-container applications. With compose we can use yaml files to configure our application’ services and then using a single command to create and start all of the configured services. I use this tool a lot when it comes to local development in a microservice environment. It is also lightweight and needs just a small effort. Instead of managing how to run each service while developing, you can have the environment and services needed preconfigured and focus on the service that you currently develop.

With docker compose , we can configure a network for our services, volumes, mount-points, environmental variables — just about everything.

To showcase this we are going to solve a problem. Our goal would be to extract data from MongoDB using Grafana. Grafana does not have out-of-the-box support for MongoD, therefore,e we will have to use a plugin.

The first step is to create our networks. Creating a network is not necessary since your services, once started, will join the default network. We will make a showcase of using custom networks, and have a network for backend services and a network for frontend services. Apparently, network configuration can get more advanced and specify custom network drivers or even configure static addresses.

version: '3.5'

networks:
  frontend:
    name: frontend-network
  backend:
    name: backend-network
    internal: true


The backend network is going to be internal so there won’t be any outbound connectivity to the containers attached to it.

Then we will setup our MongoDB instance.

version: '3.5'

services:
  mongo:
    image: mongo
    restart: always
    environment:
      MONGO_INITDB_ROOT_USERNAME: ${MONGO_USER}
      MONGO_INITDB_ROOT_PASSWORD: ${MONGO_PASSWORD}
    volumes:
      - ${DB_PATH}:/data/db
    networks:
      - backend


As you see, we specified a volume. Volumes can also be specified separately and attached to a service. We used environmental variables for the root account, and you might also have noticed that the password is going to be provided through environmental variables. The same applies for the volume path, too. You can have a more advanced configuration for volumes in your compose configuration and reference them from your service.

Our next goal is to set up the proxy server which will be in the middle of our Grafana and MongoDB server. Since it needs a custom Dockerfile to create it, we will do it through docker-compose. Compose has the capability to spin up a service by specifying the docker file.

So let’s start with the Dockerfile.

FROM node

WORKDIR /usr/src/mongografanaproxy

COPY . /usr/src/mongografanaproxy

EXPOSE 3333

RUN cd /usr/src/mongografanaproxy
RUN npm install
ENTRYPOINT ["npm","run","server"]

Then let’s add it to compose.

version: '3.5'

services:
  mongo-proxy:
    build:
      context: .
      dockerfile: ProxyDockerfile
    restart: always
    networks:
      - backend


And the same will be done to the Grafana image that we want to use. Instead of using a ready Grafana image, we will create one with the plugin preinstalled.

FROM grafana/grafana

COPY . /var/lib/grafana/plugins/mongodb-grafana

EXPOSE 3000

version: '3.5'

services:
  grafana:
    build:
      context: .
      dockerfile: GrafanaDockerfile
    restart: always
    ports:
      - 3000:3000
    networks:
      - backend
      - frontend


Let’s wrap them all together:

version: '3.5'

services:
  mongo:
    image: mongo
    restart: always
    environment:
      MONGO_INITDB_ROOT_USERNAME: ${MONGO_USER}
      MONGO_INITDB_ROOT_PASSWORD: ${MONGO_PASSWORD}
    volumes:
      - ${DB_PATH}:/data/db
    networks:
      - backend
  mongo-proxy:
    build:
      context: .
      dockerfile: ProxyDockerfile
    restart: always
    networks:
      - backend
  grafana:
    build:
      context: .
      dockerfile: GrafanaDockerfile
    restart: always
    ports:
      - 3000:3000
    networks:
      - backend
      - frontend
networks:
  frontend:
    name: frontend-network
  backend:
    name: backend-network
    internal: true


So let’s run them all together.

docker-compose -f stack.yaml build
MONGO_USER=root MONGO_PASSWORD=root DB_PATH=~/grafana-mongo  docker-compose -f stack.yaml up


This code can be found on Github, and for more, check out the Docker ImagesDocker Containers, and Docker registry posts.

Originally published by Emmanouil Gkatziouras at https://dzone.com

Learn more

Jenkins, From Zero To Hero: Become a DevOps Jenkins Master

☞ http://school.learn4startup.com/p/rIKN0OqT2

Docker Mastery: The Complete Toolset From a Docker Captain

☞ http://school.learn4startup.com/p/r18lJJ_1Te

Docker and Kubernetes: The Complete Guide

☞ http://school.learn4startup.com/p/7bXEiVS7Q

Docker Crash Course for busy DevOps and Developers

☞ http://school.learn4startup.com/p/Sy8T4CfkM

Selenium WebDriver with Docker

☞ http://school.learn4startup.com/p/9fGLIrlWl

Amazon EKS Starter: Docker on AWS EKS with Kubernetes

☞ http://school.learn4startup.com/p/TpIgI9KEN

#docker

What is GEEK

Buddha Community

Docker Basics: Docker Compose
Iliana  Welch

Iliana Welch

1595249460

Docker Explained: Docker Architecture | Docker Registries

Following the second video about Docker basics, in this video, I explain Docker architecture and explain the different building blocks of the docker engine; docker client, API, Docker Daemon. I also explain what a docker registry is and I finish the video with a demo explaining and illustrating how to use Docker hub

In this video lesson you will learn:

  • What is Docker Host
  • What is Docker Engine
  • Learn about Docker Architecture
  • Learn about Docker client and Docker Daemon
  • Docker Hub and Registries
  • Simple demo to understand using images from registries

#docker #docker hub #docker host #docker engine #docker architecture #api

August  Murray

August Murray

1615008840

Top 24 Docker Commands Explained with Examples

In my previous blog post, I have explained in detail how you can Install Docker and Docker-compose on Ubuntu

In this guide, I have explained the Top 24 Docker Commands with examples.

Make sure you have sudo or root privileges to the system.

Docker Commands

  1. The command to check the version of Docker installed.
  2. To look/search for available docker images from the Docker registry.
  3. To pull docker images from the Docker registry.
  4. Listing all the docker images
  5. Creating / Running docker container from Docker image.
  6. To list the actively running docker containers.
  7. To list all the docker containers
  8. To stop a Container
  9. To start a Container
  10. To restart a Docker container
  11. To login to running Docker container
  12. To delete the stopped Docker containers
  13. To delete Docker images from the Local system
  14. To check logs of a running Docker container
  15. Killing docker containers
  16. Log in to Docker Hub registry (hub.docker.com)
  17. Removing docker hub registry login from the system.
  18. Check active resource usage by each containers
  19. Rename a Docker container
  20. To display system wide information of Docker
  21. Inspecting a Docker container
  22. Building docker images from Docker file
  23. Creating new docker images from a Container
  24. Pushing Docker images from Local to Docker registry.

#docker #docker-command #containers #docker-compose #docker-image

Cómo instalar Drupal con Docker Compose

Введение

Docker позволяет легко помещать приложения и службы в контейнеры, чтобы их можно было запускать где угодно. Однако при работе с Docker можно легко накопить чрезмерное количество неиспользуемых образов, контейнеров и томов данных, замедляющих работу и потребляющих место на диске.

Docker предоставляет все необходимые инструменты для очистки системы из командной строки. В этом руководстве с полезными советами кратко описываются полезные команды для освобождения места на диске и организации системы посредством удаления неиспользуемых образов, контейнеров и томов Docker.

Использование этого руководства:

  • Это руководство в формате полезных советов содержит автономные сниппеты для командной строки
  • Вы можете перейти к любому разделу, актуальному для задачи, которую вы пытаетесь выполнить.

Синтаксис замены команды command $(``command``), используемый в командах, доступен во многих популярных оболочках, включая bash, zsh и Windows Powershell.

Очистка всех неиспользуемых или не связанных с контейнерами образов, контейнеров, томов и сетей

В Docker имеется команда, очищающая все не связанные с контейнерами ресурсы, в том числе образы, контейнеры, тома и сети:

docker system prune

Чтобы удалить все остановленные контейнеры и неиспользуемые образы (а не только образы, не связанные с контейнерами), добавьте в эту команду флаг -a:

docker system prune -a

Удаление образов Docker

Удаление одного или нескольких конкретных образов

Используйте команду docker images с флагом -a, чтобы найти идентификатор удаляемых образов. Эта команда покажет вам все образы, включая промежуточные слои образов. Когда вы определитесь с составом удаляемых образов, вы можете передать их идентификаторы или теги в docker rmi:

Список:

docker images -a

Удаление:

docker rmi Image Image

Удаление образов, не привязанных к контейнеру

Образы Docker состоят из нескольких слоев. Несвязанные образы — это слои, не имеющие связей с каким-либо образами с тегами. У них нет никакого назначения, и они просто занимают место на диске. Их можно найти, добавив флаг фильтра -f со значением dangling=true в команду docker images. Если вы уверены, что хотите удалить их, вы можете использовать команду docker images purge:

#drupal #docker #docker compose #docker images

Loma  Baumbach

Loma Baumbach

1600358785

Deploy a Tomcat Application Using Docker-Compose

In this blog, we will learn what is docker-compose and how we can deploy a tomcat application which uses mysql database. We will learn how we can setup a development environment using docker-compose in a single command

Prerequisite:

  1. Docker and Docker-compose installed

INTRODUCTION

  • Docker-compose is a tool which is used to deploy multi-container application.
  • One single yaml file to deploy your application on the server.
  • Best suited for the developers to setup their workstation in a single command without installing any kind of dependencies for the application
  • docker-compose up to start your application
  • docker-compose down to clean up all the docker containers

Let’s take an example here:

We have a project called user registration which uses mysql for storing the data . In terms of microservices, we can say that we have two services as shown below:

  • Web Service
  • Database Service

You can clone this git repo and try the below example

Explanation of docker-compose

  1. **version : **This is the version as per the docker engine you have installed on your machine
  2. **services: **This is the main tag which is used to configure multiple services and under that we have details of all the services

3. web: This is our service name -> using image, ports and volumes

4. **volumes: **To store the database files

Now we will create main docker-compose file which will together launch a tomcat, mysql and phpmyadmin container

Tomcat container — To run your application

**Database container **— To store the data

PhpMyAdmin — Access the database through GUI

So we will have three services

  1. db — we are using local path to store the data so that when you run docker-compose down all your data will retain. If you use the volume then all data will get lost if you run the docker-compose down

Also, we are importing sql file so that our database is ready with the sample data. It is good so that each developer will always have the base or the actual data to run their application on the local machine

2. phpmyadmin — which is used to access the database through GUI and it depends on service db

3. web — which is used to access your web application and it also depends on service db

version: '3.3'
services:
   db:
     image: mysql:5.7
     volumes:
       - /opt/test:/var/lib/mysql
       - ./mysql-dump:/docker-entrypoint-initdb.d
     environment:
       MYSQL_ROOT_PASSWORD: root
       MYSQL_DATABASE: testdb1
       MYSQL_USER: testuser
       MYSQL_PASSWORD: root
     ports:
       - 3306:3306
phpmyadmin:
    depends_on:
      - db
    image: phpmyadmin/phpmyadmin
    ports:
      - '8081:80'
    environment:
      PMA_HOST: db
      MYSQL_ROOT_PASSWORD: root
web:
    depends_on:
      - db
    image: tomcat
    volumes:
      - ./target/LoginWebApp-1.war:/usr/local/tomcat/webapps/LoginWebApp-1.war
    ports:
      - '8082:8080'
    environment:
      MYSQL_ROOT_PASSWORD: root
      MYSQL_DATABASE: testdb1
      MYSQL_USER: testuser
      MYSQL_PASSWORD: root

#docker-compose #docker-image #docker

Louis Jones

Louis Jones

1653101157

Docker Compose | What is Docker Compose?

Docker Compose | What is Docker Compose | DevOps Training

This Edureka "Docker Compose Tutorial"  will take you through the fundamentals of Docker Compose and its role in multi-container applications. You will learn what Docker and Docker compose is, the benefits of Docker compose, microservices, and how to write a compose file, basic commands of docker-compose, and finally, a demo on docker-compose where you set up and run a Django-based application using Docker-Compose. 
The following are the topics covered in the tutorial:
00:00 Agenda
01:25 What is Docker?
05:35 Why Docker-Compose
10:45 What is Docker-Compose?
15:10 Docker-Compose Installation
19:45 Docker-Compose Hands-on
37:15 Summary


Overview of Docker Compose

Compose is a tool for defining and running multi-container Docker applications. With Compose, you use a YAML file to configure your application’s services. Then, with a single command, you create and start all the services from your configuration. To learn more about all the features of Compose, see the list of features.

Compose works in all environments: production, staging, development, testing, as well as CI workflows. You can learn more about each case in Common Use Cases.

Using Compose is basically a three-step process:

Define your app’s environment with a Dockerfile so it can be reproduced anywhere.

Define the services that make up your app in docker-compose.yml so they can be run together in an isolated environment.

Run docker compose up and the Docker compose command starts and runs your entire app. You can alternatively run docker-compose up using the docker-compose binary.

A docker-compose.yml looks like this:

version: "3.9"  # optional since v1.27.0
services:
  web:
    build: .
    ports:
      - "8000:5000"
    volumes:
      - .:/code
      - logvolume01:/var/log
    links:
      - redis
  redis:
    image: redis
volumes:
  logvolume01: {}

Compose has commands for managing the whole lifecycle of your application:

  • Start, stop, and rebuild services
  • View the status of running services
  • Stream the log output of running services
  • Run a one-off command on a service

Compose V2 and the new docker compose command

Important

The new Compose V2, which supports the compose command as part of the Docker CLI, is now available.

Compose V2 integrates compose functions into the Docker platform, continuing to support most of the previous docker-compose features and flags. You can run Compose V2 by replacing the hyphen (-) with a space, using docker compose, instead of docker-compose.

If you rely on using Docker Compose as docker-compose (with a hyphen), you can set up Compose V2 to act as a drop-in replacement of the previous docker-compose. Refer to the Installing Compose section for detailed instructions.

Context of Docker Compose evolution

Introduction of the Compose specification makes a clean distinction between the Compose YAML file model and the docker-compose implementation. Making this change has enabled a number of enhancements, including adding the compose command directly into the Docker CLI, being able to “up” a Compose application on cloud platforms by simply switching the Docker context, and launching of Amazon ECS and Microsoft ACI. As the Compose specification evolves, new features land faster in the Docker CLI.

Compose V2 relies directly on the compose-go bindings which are maintained as part of the specification. This allows us to include community proposals, experimental implementations by the Docker CLI and/or Engine, and deliver features faster to users. Compose V2 also supports some of the newer additions to the specification, such as profiles and GPU devices.

Compose V2 has been re-written in Go, which improves integration with other Docker command-line features, and allows it to run natively on macOS on Apple silicon, Windows, and Linux, without dependencies such as Python.

For more information about compatibility with the compose v1 command-line, see the docker-compose compatibility list.

Features

The features of Compose that make it effective are:

Multiple isolated environments on a single host

Compose uses a project name to isolate environments from each other. You can make use of this project name in several different contexts:

  • on a dev host, to create multiple copies of a single environment, such as when you want to run a stable copy for each feature branch of a project
  • on a CI server, to keep builds from interfering with each other, you can set the project name to a unique build number
  • on a shared host or dev host, to prevent different projects, which may use the same service names, from interfering with each other

The default project name is the basename of the project directory. You can set a custom project name by using the -p command line option or the COMPOSE_PROJECT_NAME environment variable.

The default project directory is the base directory of the Compose file. A custom value for it can be defined with the --project-directory command line option.

Preserve volume data when containers are created

Compose preserves all volumes used by your services. When docker-compose up runs, if it finds any containers from previous runs, it copies the volumes from the old container to the new container. This process ensures that any data you’ve created in volumes isn’t lost.

If you use docker-compose on a Windows machine, see Environment variables and adjust the necessary environment variables for your specific needs.

Only recreate containers that have changed

Compose caches the configuration used to create a container. When you restart a service that has not changed, Compose re-uses the existing containers. Re-using containers means that you can make changes to your environment very quickly.

Variables and moving a composition between environments

Compose supports variables in the Compose file. You can use these variables to customize your composition for different environments, or different users. See Variable substitution for more details.

You can extend a Compose file using the extends field or by creating multiple Compose files. See extends for more details.

Common use cases

Compose can be used in many different ways. Some common use cases are outlined below.

Development environments

When you’re developing software, the ability to run an application in an isolated environment and interact with it is crucial. The Compose command line tool can be used to create the environment and interact with it.

The Compose file provides a way to document and configure all of the application’s service dependencies (databases, queues, caches, web service APIs, etc). Using the Compose command line tool you can create and start one or more containers for each dependency with a single command (docker-compose up).

Together, these features provide a convenient way for developers to get started on a project. Compose can reduce a multi-page “developer getting started guide” to a single machine readable Compose file and a few commands.

Automated testing environments

An important part of any Continuous Deployment or Continuous Integration process is the automated test suite. Automated end-to-end testing requires an environment in which to run tests. Compose provides a convenient way to create and destroy isolated testing environments for your test suite. By defining the full environment in a Compose file, you can create and destroy these environments in just a few commands:

$ docker-compose up -d
$ ./run_tests
$ docker-compose down

Single host deployments

Compose has traditionally been focused on development and testing workflows, but with each release we’re making progress on more production-oriented features.

For details on using production-oriented features, see compose in production in this documentation.

Release notes

To see a detailed list of changes for past and current releases of Docker Compose, refer to the CHANGELOG.

Getting help

Docker Compose is under active development. If you need help, would like to contribute, or simply want to talk about the project with like-minded individuals, we have a number of open channels for communication.

To report bugs or file feature requests: use the issue tracker on Github.

To talk about the project with people in real time: join the #docker-compose channel on the Docker Community Slack.

To contribute code or documentation changes: submit a pull request on Github.

#docker #devops