====== Docker stuff ======

[[https://www.freecodecamp.org/news/a-beginners-guide-to-docker-how-to-create-your-first-docker-application-cc03de9b639f/]]

This assumes you are running Docker on Linux, if anybody actually **wants** to use windows, see here:- [[https://www.disney.co.uk/mickey-mouse| Docker on windows]]


===== Build container from Dockerfile =====

This adds a Repository and tag, note the ''.'' at the end is required, it means look in this directory for the Dockerfile:-

  # docker build -t unit/abc:apache2-wsgi .
  
  # docker build -t friendlyello --tag=friendlyhello .
  
  # docker image ls
  REPOSITORY                 TAG            IMAGE ID       CREATED          SIZE
  unit/abc                   apache2-wsgi   324aaa642a04   10 seconds ago   300MB


==== Export image to file ====


  # docker save 601fc78e12f7  > ../wsgi-apache2-v2.tar

==== Import image to Docker ====


<code>
root@ubuntu20:~# docker load < wsgi-apache2.tar
ee8944188361: Loading layer [===========================================>]  7.642MB/7.642MB
de7495326c39: Loading layer [===========================================>]  20.48kB/20.48kB
927524753f9c: Loading layer [===========================================>]  20.48kB/20.48kB
378475152b3a: Loading layer [===========================================>]  20.48kB/20.48kB
28d8ea9c3303: Loading layer [===========================================>]  20.99kB/20.99kB
bd7760437189: Loading layer [===========================================>]   2.56kB/2.56kB
Loaded image ID: sha256:5326892bf34d703dccd6d2281baf7dd482d813ccaf4f322639ddc89b2c439700


root@ubuntu20:~# docker image ls
REPOSITORY                 TAG            IMAGE ID       CREATED         SIZE
uit/abc                    apache2-wsgi   324aaa642a04   11 days ago     300MB
</code>


===== Running container =====

| -p 8080:80  |  Map TCP port 80 in the container to port 8080 on the Docker host. |
| -p 192.168.1.100:8080:80  |  Map TCP port 80 in the container to port 8080 on the Docker host for connections to host IP 192.168.1.100 |


<code bash>
# docker run -d  -p 80:80 324aaa642a04
e0733a7c4fb9bded46e5c0f4f4abd9919ff58a61b311bda4265acfe7dc534e32

# docker ps
CONTAINER ID   IMAGE              COMMAND                  CREATED          STATUS         PORTS                                                  NAMES
e0733a7c4fb9   324aaa642a04       "httpd -D FOREGROUND…"   10 seconds ago   Up 8 seconds   0.0.0.0:80->80/tcp, :::80->80/tcp                      amazing_swartz
</code>

Note ''docker ps -a'' shows a history of containers.


''docker logs <container_name>''


===== Docker exec =====

https://devconnected.com/docker-exec-command-with-examples/
==== Run bash shell in container ====


  # docker exec -it e0733a7c4fb9  /bin/bash



$ docker run -it python-docker-test

docker stop 1bd7ed055412





docker info

docker inspect <container id>


docker image rm

$ docker build --tag python-docker-test .

<code>
$ docker run --name andrew1 -d -p 4000:80 bae2beae2108
d37e2100cbf0fc61b9cd21ceb0734e19b501c3888fa4bb1411f99a5c2d6beb0a


$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                  NAMES
d37e2100cbf0        bae2beae2108        "python app.py"     4 seconds ago       Up 3 seconds        0.0.0.0:4000->80/tcp   andrew1
$
</code>


Start and stop containers, background to daemon mode with ''-d''.
<code>
$ docker-compose up -d
Recreating 2ndtest_redis_1 ... done
Recreating 2ndtest_web_1   ... done
$ 
$ docker-compose down
Stopping 2ndtest_web_1   ... done
Stopping 2ndtest_redis_1 ... done
Removing 2ndtest_web_1   ... done
Removing 2ndtest_redis_1 ... done
Removing network 2ndtest_default
$ 
</code>

<code>
docker-compose.yml

version: '3'

services:
  web:
    build: .
    image: flask_web
    ports:
     - "5000:5000"
    links:
      - redis
    networks:
      - flask_app
    environment:
      - REDIS_URL=redis://cache
    restart: unless-stopped

  redis:
    image: "redis:alpine"
    container_name: cache
    networks:
      - flask_app
    restart: unless-stopped

networks:
  flask_app:
    driver: bridge
</code>


Run flask bound to external interface:- ### python3 -m flask run --host=0.0.0.0

Or:- flask --app sample --debug run


====== Bind mount persistent storage ======

[[https://docs.docker.com/storage/]]
====== Alpine Linux ======

Install Python
  RUN apk update && apk upgrade
  RUN apk add python3 py3-pip


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