Build docker containers.

```console
cd ..

docker build -t mscp-ubuntu:20.04 -f docker/ubuntu-20.04.Dockerfile .

docker build -t mscp-ubuntu:22.04 -f docker/ubuntu-22.04.Dockerfile .

docker build -t mscp-centos:8 -f docker/centos-8.Dockerfile .

docker build -t mscp-rocky:8.6 -f docker/rocky-8.6.Dockerfile .
```

Test `mscp` in the containers.

```console
docker run --init --rm mscp-ubuntu:20.04 /mscp/scripts/test-in-container.sh

docker run --init --rm mscp-ubuntu:22.04 /mscp/scripts/test-in-container.sh

docker run --init --rm mscp-centos:8 /mscp/scripts/test-in-container.sh

docker run --init --rm mscp-rocky:8.6 /mscp/scripts/test-in-container.sh
```

Retrieve deb/rpm packages.

```console
docker run --rm -v (pwd):/out mscp-ubuntu:20.04 \
       cp /mscp/build/mscp_0.0.0-ubuntu-20.04-x86_64.deb /out/

docker run --rm -v (pwd):/out mscp-ubuntu:22.04 \
       cp /mscp/build/mscp_0.0.0-ubuntu-22.04-x86_64.deb /out/

docker run --rm -v (pwd):/out mscp-centos:8 \
       cp /mscp/build/mscp_0.0.0-centos-8-x86_64.rpm /out/

docker run --rm -v (pwd):/out mscp-rocky:8.6 \
       cp /mscp/build/mscp_0.0.0-rocky-8.6-x86_64.rpm /out/
```

I don't know whether these are good way.