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podman-compose  (equivelent to older command "docker-compose")

"podman-compose" is used run one or more containers, which is defined by
a "docker-compose.yml" file in the currect directory.

  docker-compose file format
    https://docs.docker.com/compose/compose-file/compose-file-v3

  Beginner's Guide to Using Podman Compose
    https://linuxhandbook.com/podman-compose/

The file defines a LOT of information, such as
What volumes, secrets, networks; are to be attached
And if it should restart on failure.

You can also specify how to build the image to use image from
a specific "Dockerfile", or directory with a "Dockerfile".
Or even from a Dockerfile in-line in the compose file.

Many examples are provided on DockerHub for each provided image.
But a more comprehensive example with commented optiosn ais given below.

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Example Commands...

Create podman image from "Dockerfile"...
In this case a modified  "php:7.4-apache" image from Dockerhub
  podman build -t php7.4-apache ./

See the created images,
  podman images
  podman image ls

Start container from "docker-compose.yml" file...
  sudo systemctl start podman-compose.service
equivelent to...
  podman-compose up -d
If a UserNS is also needed, a environment variable must be set...
  PODMAN_USERNS=$(grep -Po 'userns_mode: "\K[^"]+' docker-compose.yml) \
    podman-compose up -d

Stop container...
  sudo systemctl stop podman-compose.service

Or manually...
  podman-compose down -v

See the container process...
  podman-compose ps

Note that the running container is named (see output of previous command)...
  {dir}_{service}_1

Check systemd status...
  sudo systemctl status -l podman-compose.service
Check logs (all of them)...
  sudo journalctl -u podman-compose.service

Check a specific container logs...
  podman logs {container}
You launch a shell into that container to examine it...
  podman exec -u 0 -it {container} /bin/bash

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Start/Stop specific container services...

start just one specific container
  podman-compose up -d mysql

Work on a specific service of this compose file
  podman-compose start mysql
  podman-compose stop mysql
  podman-compose restart mysql

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Images

   podman-compose build    # build the images
   podman-compose pull     # pull/build the images needed

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Example "docker-compose.yml" files


For networking....
=======8<--------CUT HERE----------
  web:
    ...
    # for a system process - expose all ports as needed
    network_mode: 'host'

    # to expose only specific ports to the system
    network_mode: 'slirp4netns:port_handler=slirp4netns'
    ports:
      - '8080:8080'

=======8<--------CUT HERE----------


=======8<--------CUT HERE----------
---
#
# Configuartion to Start 2 containers: a web srevice, and redis service
# Most of these options are probably NOT needed for your containers
#
version: '3.1'

services:

  web:
    image: 'localhost/php7.4-apache'   # local image (to be built)
    #build: .                          # Dockerfile to build image (optional)
    #container_name: web               # running container name (optional)
    restart: 'always'
    environment:
      TZ: 'Australia/Brisbane'
    volumes:
      - "./html:/var/www/html:z"                              # web-data
      - "fullchain.pem:/etc/ssl/certs/ssl-cert-snakeoil.pem"  # certs
      - "privkey.pem:/etc/ssl/private/ssl-cert-snakeoil.key"
    ports:
      - 80:80
      - 443:443

    # These are for secure interfacing (services, passwords, etc)
    depends-on:
      - redis           # redis server must be started before this
    networks:
      - net_redis       # private network connection to redis
    secrets:
      - sso_auth_data   # secret information to enable SSO single signon

    # deploy:           # This is only used for swarm container deployments.
    #   mode: replicated
    #   replicas: 3
    #   # placement:    # limit what servers it runs on
    #   #   constraints: [ node.role == manager ]

  redis:
    image: remote.registery./library/redis
    restart: 'always'
    networks:
      - net_redis

# Create a private network between containers
networks:
  # network allowing communications to redis
  net_redis:
    driver: overlay

# Special 'secret' volumes,
# data stored in podman (write-only) using  podman secret ...
# only readable within the container in a special location
secrets:
  sso_auth_data:
    external: true

...
=======8<--------CUT HERE----------



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