Podman : Use Dockerfile2023/06/21

	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
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: MAINTAINER ServerWorld <admin@srv.world>
--> 00970b06f91
STEP 3/7: RUN apt-get update

.....
.....

COMMIT srv.world/debian-nginx:latest
--> e2938e55cf7
Successfully tagged srv.world/debian-nginx:latest
e2938e55cf7cbd06ac0c38b967476b4897f464ff74fc16f88cb4f0c30fe1895e

root@dlp:~#

podman images

REPOSITORY                TAG         IMAGE ID      CREATED             SIZE
srv.world/debian-nginx    latest      e2938e55cf7c  About a minute ago  158 MB
srv.world/debian-apache2  latest      f047c6f28c56  8 minutes ago       260 MB
docker.io/library/debian  latest      49081a1edb0b  8 days ago          121 MB

# run container

root@dlp:~#

podman run -d -p 80:80 srv.world/debian-nginx

fd506a88790a2a0c3cdda70f3b5d9be3041b145a0df0bfcdd6d393cce319ca5c

root@dlp:~#

podman ps

CONTAINER ID  IMAGE                          COMMAND               CREATED         STATUS             PORTS               NAMES
fd506a88790a  srv.world/debian-nginx:latest  /usr/sbin/nginx -...  11 seconds ago  Up 11 seconds ago  0.0.0.0:80->80/tcp  festive_clarke

# 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": "10.88.0.11",
                    "IPAddress": "10.88.0.11",

root@dlp:~#

curl 10.88.0.11

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.
MAINTAINER	It sets the Author field of the generated images.
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.

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