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==Common commands==
<syntaxhighlight lang="bash">
docker build  -t <name:latest> .
docker ps
docker logs <name>
docker stop <name>
docker rm <name>
docker run --name <name> --net=host -d  -p 8000:5000 --rm -e MAIL_USERNAME=iwiseman -e ENVIRONMENT2=env2
# With Bash
docker exec -it <name> /bin/bash
# Without Bash
docker exec -it microblog /bin/sh
</syntaxhighlight>
'''Not''' --net=host allows you to connect to localhost e.g. localhost:3306 (mysql)
===Other Commmand===
<syntaxhighlight lang="bash">
#Show the current docker image running
sudo docker ps


#Show the images available
sudo docker images
#Stop a container id
sudo docker stop <container id>
#Start a container id
sudo docker stop <container id>
#Show ports exposed
sudo docker port <container id>
#List current containers
sudo docker container ls -s
#Remove a container
sudo docker container rm <container id>
#Pull a container
sudo docker pull <image name>
#This will remove all images without at least one container associated to them
#docker image prune -a
#This will remove all stopped containers
docker container prune
</syntaxhighlight>
=Build Container=
==RUN command==
RUN su-exec volpara git clone https://github.com/bibble235/aports
==Copying from on container==
Given the container
FROM ubuntu:18.04 AS opencv_build
Copying can be done using
COPY --from=opencv_build /usr/local/opencv/ /usr/local/
== Creating a docker postgres image ==
This exposes the default port 5432 for postgres
docker run --name postgresq-spring -e POSTGRES_USER=iain -e POSTGRES_PASSWORD=password -p 5432:5432 -v /data:/var/lib/postgresql/data -d postgres:alpine
The -d is to run the container in the background<br>
The postgres:alpine is the image name<br>
The -p is the port to expose which is the default for postgress
The -v is where the data will be stored
== Volumes ==
List volumes
docker volume ls
Create a volumes
docker volume create hello
==Running a Container==
Sample for running a container with name test, ip 172,18.0.11, network to run on as billnet, capital P to expose the port (not for production), remove container when exit, it to have the errors go to the host console, and ps/dataservice for the image name
  docker run --name test --ip=172,18.0.11 --net=billnet -P --rm -it ps/dataservice
=Build MediaWiki Container=
==Build your own Docker Image==
Get the definition from github and build the container.
<syntaxhighlight lang="bash">
https://github.com/wikimedia/mediawiki-docker/blob/38d4e7f77f8b5b4efda91f969ccba2475fc2c597/1.35/apache/Dockerfile
docker build .
</syntaxhighlight>
==Use Prebuilt==
We can install the prebuilt one with
<syntaxhighlight lang="bash">
docker pull mediawiki
</syntaxhighlight>
<br>
We can find the container with the command
<syntaxhighlight lang="bash">
docker ps --format "table {{.ID}}\t{{.Status}}\t{{.Names}}"
b0ff6611123e  Up 2 minutes  some-mediawiki
898c8f40818d  Up 6 hours    k8s_operator_openshift-web...
b02230ae7074  Up 6 hours    k8s_kube-dns_kube-dns-qhbvf_....
ea19641bc9a1  Up 6 hours    k8s_webconsole_webconsole-...
0dc6ee563a9b  Up 6 hours    k8s_registry_docker-registry-...
0b6ea1064152  Up 6 hours    k8s_operator_openshift-servic...
...
</syntaxhighlight>
From there we can get the ip address with
<syntaxhighlight lang="bash">
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' b0ff6611123e
172.17.0.9
</syntaxhighlight>
==Delete Container==
We can stop the contain and delete it
<syntaxhighlight lang="bash">
docker stop b0ff6611123e
docker container rm b0ff6611123e
</syntaxhighlight>
=Docker Compose=
==Simple MYSQL Compose Container==
This is an example of a mysql. The ports are changed to stop collision with desktop.
<syntaxhighlight lang="bash">
version: '3.8'
networks:
  default:
services:
  db:
    image: mysql:5.7
    container_name: conference_security
    ports:
      - 3307:3306
    volumes:
      - "./.data/db:/var/lib/mysql"
    environment:
      MYSQL_ROOT_PASSWORD: pass
      MYSQL_DATABASE: TEST_DB   
</syntaxhighlight>
==Creating A Container With Composer==
* Create a requirements.txt document with what is required for the container
* Create a Docker File definition
* Create a composer file
==Django Container==
===Requirements===
Here are the specific requirements for the Django cotainer.
<syntaxhighlight lang="bash">
Django==3.1.5
djangorestframework==3.12.2
mysqlclient==2.0.3
django-mysql==3.10.0
django-cors-headers==3.6.0
pika==1.1.0
</syntaxhighlight>
===DockerFile===
This command runs the django app at start up
<syntaxhighlight lang="Dockerfile">
FROM python:3.9
ENV  PYTHONNUMBUFFERED 1
WORKDIR /app
COPY requirements.txt /app/requirements.txt
RUN pip install -r requirements.txt
COPY . /app
</syntaxhighlight>
===Yaml===
We can build a container using docker-compose. Create a docker file with
<syntaxhighlight lang="Dockerfile">
version: '3.8'
services:
  django:
    container_name: djangoapp
    build:
      context: .
      dockerfile: Dockerfile
    command: 'python3 manage.py runserver 0.0.0.0:8000'
    ports:
      - 8000:8000
    volumes:
      - .:/app
    depends_on:
      - db
    networks:
      django_demo:
  queue:
    environment:
      - PYTHONUNBUFFERED=1
    build:
      context: .
      dockerfile: Dockerfile
    container_name: djangoqueue
    command: 'python3 consumer.py'
    depends_on:
      - db
    networks:
      django_demo:
  db:
    image: mysql:5.7.32
    container_name: djangodb
    restart: always
    environment:
      MYSQL_DATABASE: admin
      MYSQL_USER: root
      MYSQL_PASSWORD: root
      MYSQL_ROOT_PASSWORD: root
    volumes:
      - .dbdata:/var/lib/mysql
    ports:
      - 33066:3306
    networks:
      django_demo:
networks:
  django_demo:
    external: true
</syntaxhighlight>
==Flask Container==
===Requirements===
Here are the specific requirements for the Flask container.
<syntaxhighlight lang="bash">
Flask==1.1.2
Flask-SQLAlchemy==2.4.4
SQLAlchemy==1.3.20
Flask-Migrate==2.5.3
Flask-Script==2.0.6
Flask-Cors==3.0.9
requests==2.25.0
mysqlclient==2.0.3
pika==1.1.0
</syntaxhighlight>
===DockerFile===
This command runs the flask app at start up
<syntaxhighlight lang="Dockerfile">
FROM python:3.9
ENV  PYTHONNUMBUFFERED 1
WORKDIR /app
COPY requirements.txt /app/requirements.txt
RUN pip install -r requirements.txt
COPY . /app
</syntaxhighlight>
===Yaml===
We can build a container using docker-compose. Create a docker file with
<syntaxhighlight lang="Dockerfile">
version: '3.8'
services:
  flask:
    build:
      context: .
      dockerfile: Dockerfile
    container_name: flaskapp
    command: python main.py
    ports:
      - 8001:5000
    volumes:
      - .:/app
    depends_on:
      - db
    networks:
      django_demo:
  queue:
    build:
      context: .
      dockerfile: Dockerfile
    container_name: flaskqueue
    command: 'python consumer.py'
    depends_on:
      - db
    networks:
      django_demo:
  db:
    image: mysql:5.7.32
    container_name: flaskdb
    restart: always
    environment:
      MYSQL_DATABASE: main
      MYSQL_USER: root
      MYSQL_PASSWORD: root
      MYSQL_ROOT_PASSWORD: root
    volumes:
      - .dbdata:/var/lib/nysql
    ports:
      - 33067:3306
    networks:
      django_demo:
networks:
  django_demo:
    external: true
</syntaxhighlight>
=Networking with Docker Compose=
==General==
In order to connect on the network container to container I ended up setting up my own network.
<syntaxhighlight lang="bash">
docker network create --attachable django_demo
</syntaxhighlight>
Once we have the network we can assign the containers to the network by setting the network name and the network in this case django_demo
<syntaxhighlight lang="yaml">
version: '3.8'
services:
  django:
    container_name: djangoapp
    build:
      context: .
      dockerfile: Dockerfile
    command: 'python manage.py runserver 0.0.0.0:8000'
    ports:
      - 8000:8000
    volumes:
      - .:/app
    depends_on:
      - db
    networks:
      django_demo:
...
networks:
  django_demo:
    external: true     
</syntaxhighlight>
We need to specify the container_name because the default is to use the service name an, underscore and a number which in this case would have been django_1. This creates an invalid host as the underscore is not allowed.
==Commands==
We can see the network with
<syntaxhighlight lang="bash">
docker network inspect django_demo
</syntaxhighlight>
We can delete network with
<syntaxhighlight lang="bash">
docker network prune
</syntaxhighlight>
And we can see the containers with
<syntaxhighlight lang="bash">
docker ps
</syntaxhighlight>
==Django Specific==
===Allowed Hosts===
To ensure no errors we need to specify which hosts django allows. This is done in the settings.py. In this example the container name for the app is put in the allowed list.
<syntaxhighlight lang="python">
...
ALLOWED_HOSTS = ['127.0.0.1','djangoapp']
...
</syntaxhighlight>
===App Database Connection===
We need to also need to account for the hostname when using the container_name in the docker-compose yml
<syntaxhighlight lang="python">
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'dont',
        'USER': 'copy',
        'PASSWORD': 'this',
        'HOST': 'djangodb',
        'PORT': '3306'
    }
}
</syntaxhighlight>
==Flask==
===App Database Connection===
In this case I created a flask app so the database is specified in the main.py in the SQLALCHEMY_DATABASE_URI. Here we use the hostname for URI.
<syntaxhighlight lang="python">
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:root@flaskdb/main'
</syntaxhighlight>
===Container to Container===
To call the django service we do this by using the hostname of the django service. In our case.
<syntaxhighlight lang="python">
...
  req = requests.get('http://djangoapp:8000/api/user')
  return jsonify(req.content.decode('utf-8'))
</syntaxhighlight>

Revision as of 07:44, 16 August 2021

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