Podman : Use Dockerfile

	Use Dockerfile and create Container images automatically. It is also useful for configuration management for Container images.
[1]	For example, Create a Dockerfile that Nginx is installed and started.

root@dlp:~#  vi Dockerfile # create new FROM debian LABEL Maintainer "ServerWorld <admin@srv.world>" RUN apt-get update RUN apt-get -y install nginx RUN echo "Dockerfile Test on Nginx" > /var/www/html/index.html EXPOSE 80 CMD ["/usr/sbin/nginx", "-g", "daemon off;"] # build image ⇒ podman build -t [image name]:[tag] . root@dlp:~#  podman build -t srv.world/debian-nginx:latest . STEP 1/7: FROM debian STEP 2/7: LABEL Maintainer "ServerWorld <admin@srv.world>" --> b297213dbe62 STEP 3/7: RUN apt-get update ..... ..... COMMIT srv.world/debian-nginx:latest --> 33b7b5b10b13 Successfully tagged srv.world/debian-nginx:latest 33b7b5b10b139dea3a74317cc07172214360a6df956f4799b84dfb3e8b1b2cc0 root@dlp:~#  podman images REPOSITORY TAG IMAGE ID CREATED SIZE srv.world/debian-nginx latest 33b7b5b10b13 About a minute ago 157 MB srv.world/debian-apache2 latest a0aca892bf29 8 minutes ago 234 MB docker.io/library/debian latest 047bd8d81940 11 days ago 124 MB # run container root@dlp:~#  podman run -d -p 80:80 srv.world/debian-nginx 05470306188d35c1a6367f585d5f8656c041fe88ca2ec50f2cc7db4588d23691 root@dlp:~#  podman ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 05470306188d srv.world/debian-nginx:latest /usr/sbin/nginx -... 9 seconds ago Up 9 seconds 0.0.0.0:80->80/tcp exciting_noyce # verify accesses root@dlp:~#  curl localhost Dockerfile Test on Nginx # also possible to access via container network root@dlp:~#  podman inspect -l | grep \"IPAddress "IPAddress": "10.88.0.15", "IPAddress": "10.88.0.15", root@dlp:~#  curl 10.88.0.15 Dockerfile Test on Nginx

The format of Dockerfile is [INSTRUCTION arguments] . Refer to the following description for INSTRUCTION. INSTRUCTION Description FROM It sets the Base Image for subsequent instructions. RUN It will execute any commands when Docker image will be created. CMD It will execute any commands when Docker container will be executed. ENTRYPOINT It will execute any commands when Docker container will be executed. LABEL It adds metadata to an image. EXPOSE It informs Docker that the container will listen on the specified network ports at runtime. ENV It sets the environment variable. ADD It copies new files, directories or remote file URLs. COPY It copies new files or directories. The differences of [ADD] are that it's impossible to specify remote URL and also it will not extract archive files automatically. VOLUME It creates a mount point with the specified name and marks it as holding externally mounted volumes from native host or other containers. USER It sets the user name or UID. WORKDIR It sets the working directory.