Rocky_Linux_8
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Podman : Use Docker Compose
2021/07/29
 
To Install Docker Compose, it's easy to configure and run multiple containers as a Docker application.
Docker Compose is supported on Podman 3.0 or later.
[1]
[2] Install Docker Compose.
[root@dlp ~]#
curl -L https://github.com/docker/compose/releases/download/1.29.2/docker-compose-$(uname -s)-$(uname -m) -o /usr/local/bin/docker-compose
[root@dlp ~]#
chmod 755 /usr/local/bin/docker-compose
[root@dlp ~]#
docker-compose --version

docker-compose version 1.29.2, build 5becea4c
[root@dlp ~]#
podman version

Version:      3.0.2-dev
API Version:  3.0.0
Go Version:   go1.15.7
Built:        Fri Jun 11 11:48:26 2021
OS/Arch:      linux/amd64
[3] For example, Configure an application that has Web and DB services with Docker Compose.
# start podman.socket

[root@dlp ~]#
systemctl start podman.socket
# define Web service container

[root@dlp ~]#
vi Dockerfile
FROM docker.io/rockylinux/rockylinux
MAINTAINER ServerWorld <admin@srv.world>

RUN dnf -y install nginx

EXPOSE 80
CMD ["/usr/sbin/nginx", "-g", "daemon off;"]

# define application configration

[root@dlp ~]#
vi docker-compose.yml
version: '3'
services:
  db:
    image: docker.io/library/mariadb
    volumes:
      - /var/lib/containers/disk01:/var/lib/mysql
    environment:
      MYSQL_ROOT_PASSWORD: password
      MYSQL_USER: rocky
      MYSQL_PASSWORD: password
      MYSQL_DATABASE: rocky_db
    ports:
      - "3306:3306"
  web:
    build: .
    ports:
      - "80:80"
    volumes:
      - /var/lib/containers/disk02:/usr/share/nginx/html

[root@dlp ~]#
mkdir /var/lib/containers/disk01

[root@dlp ~]#
mkdir /var/lib/containers/disk02
# buid and run

[root@dlp ~]#
docker-compose up -d

Creating network "root_default" with the default driver
Building web
STEP 1: FROM docker.io/rockylinux/rockylinux
STEP 2: MAINTAINER ServerWorld <admin@srv.world>
STEP 3: RUN dnf -y install nginx
.....
.....
Creating root_web_1 ... done
Creating root_db_1  ... done

[root@dlp ~]#
podman ps

CONTAINER ID  IMAGE                             COMMAND               CREATED             STATUS                 PORTS                   NAMES
264db88633da  docker.io/library/mariadb:latest  mysqld                About a minute ago  Up About a minute ago  0.0.0.0:3306->3306/tcp  root_db_1
a328e6fe28d7  localhost/root_web:latest         /usr/sbin/nginx -...  About a minute ago  Up About a minute ago  0.0.0.0:80->80/tcp      root_web_1

# verify accesses

[root@dlp ~]#
mysql -h 127.0.0.1 -u root -p -e "show variables like 'hostname';"

Enter password:
+---------------+--------------+
| Variable_name | Value        |
+---------------+--------------+
| hostname      | 264db88633da |
+---------------+--------------+

[root@dlp ~]#
mysql -h 127.0.0.1 -u rocky -p -e "show databases;"

Enter password:
+--------------------+
| Database           |
+--------------------+
| rocky_db           |
| information_schema |
+--------------------+

[root@dlp ~]#
echo "Hello Docker Compose World" > /var/lib/containers/disk02/index.html

[root@dlp ~]#
curl 127.0.0.1

Hello Docker Compose World
[4] Other basic operations of Docker Compose are follows.
# verify state of containers

[root@dlp ~]#
docker-compose ps

   Name                 Command               State        Ports
---------------------------------------------------------------------
root_db_1    docker-entrypoint.sh mysqld      Up      :3306->3306/tcp
root_web_1   /usr/sbin/nginx -g daemon off;   Up      :80->80/tcp

# show logs of containers

[root@dlp ~]#
docker-compose logs

Attaching to root_db_1, root_web_1
db_1   | 2021-07-29 07:20:05+00:00 [Note] [Entrypoint]: Entrypoint script for MariaDB Server 1:10.6.3+maria~focal started.
db_1   | 2021-07-29 07:20:05+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
db_1   | 2021-07-29 07:20:05+00:00 [Note] [Entrypoint]: Entrypoint script for MariaDB Server 1:10.6.3+maria~focal started.
db_1   | 2021-07-29 07:20:05+00:00 [Note] [Entrypoint]: Initializing database files

.....
.....

db_1   | 2021-07-29  7:20:12 0 [Warning] 'proxies_priv' entry '@% root@264db88633da' ignored in --skip-name-resolve mode.
db_1   | 2021-07-29  7:20:12 0 [Note] mysqld: ready for connections.
db_1   | Version: '10.6.3-MariaDB-1:10.6.3+maria~focal'  socket: '/run/mysqld/mysqld.sock'  port: 3306  mariadb.org binary distribution

# run any commands inside a container

# container name is just the one set in [docker-compose.yml]

[root@dlp ~]#
docker-compose exec db /bin/bash

Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg.
root@264db88633da:/#

# stop application and also shutdown all containers

[root@dlp ~]#
docker-compose stop

Stopping root_db_1  ...
Stopping root_web_1 ...
Stopping root_web_1 ... done
Stopping root_db_1  ... done

# start a service alone in application

# if set dependency, other container starts

[root@dlp ~]#
docker-compose up -d web

Starting root_web_1 ... done
[root@dlp ~]#
docker-compose ps

   Name                 Command               State         Ports
----------------------------------------------------------------------
root_db_1    docker-entrypoint.sh mysqld      Exit 0   :3306->3306/tcp
root_web_1   /usr/sbin/nginx -g daemon off;   Up       :80->80/tcp

# remove all containers in application

# if a container is running, it won't be removed

[root@dlp ~]#
docker-compose rm

Going to remove root_db_1
Are you sure? [yN] y
Removing root_db_1 ... done
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