Fedora 37
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Podman : Use Dockerfile2022/11/22

 
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 fedora
MAINTAINER ServerWorld <admin@srv.world>

RUN dnf -y install nginx
RUN echo "Dockerfile Test on Nginx" > /usr/share/nginx/html/index.html

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

# build image ⇒ docker build -t [image name]:[tag] .

[root@dlp ~]#
podman build -t srv.world/fedora-nginx:latest .

STEP 1/6: FROM fedora
STEP 2/6: MAINTAINER ServerWorld <admin@srv.world>
--> dd191983268
STEP 3/6: RUN dnf -y install nginx
.....
.....
Successfully tagged srv.world/fedora-nginx:latest
3e184c6f4609939436185c6c26458821a7346d0b5ebb855a4feff1cad7738c00

[root@dlp ~]#
podman images

REPOSITORY                         TAG         IMAGE ID      CREATED         SIZE
srv.world/fedora-nginx             latest      3e184c6f4609  21 seconds ago  430 MB
srv.world/fedora-httpd             latest      87f2afc7b89d  12 minutes ago  458 MB
registry.fedoraproject.org/fedora  latest      885d2b38b819  11 days ago     190 MB

# run container

[root@dlp ~]#
podman run -d -p 80:80 srv.world/fedora-nginx

77ddb57198022e638ad11e4fb022eaa5be781a3f008e7b9ccb467355405ff9fe

[root@dlp ~]#
podman ps

CONTAINER ID  IMAGE                          COMMAND               CREATED         STATUS             PORTS               NAMES
77ddb5719802  srv.world/fedora-nginx:latest  /usr/sbin/nginx -...  23 seconds ago  Up 23 seconds ago  0.0.0.0:80->80/tcp  hardcore_goldstine

# 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": "10.88.0.14",
                         "IPAddress": "10.88.0.14",

[root@dlp ~]#
curl 10.88.0.14

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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