Fedora 36
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Podman : Use Dockerfile2022/05/24
 
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>
--> 29633312a74
STEP 3/6: RUN dnf -y install nginx
.....
.....
Successfully tagged srv.world/fedora-nginx:latest
bfad5d240798977a452fbad0ef1d5d707b9ba342248e15ab4e11fcee148e0d35
[root@dlp ~]#
podman images 

REPOSITORY                         TAG         IMAGE ID      CREATED         SIZE
srv.world/fedora-nginx             latest      bfad5d240798  22 seconds ago  467 MB
srv.world/fedora-httpd             latest      6c88b642f75c  7 minutes ago   566 MB
registry.fedoraproject.org/fedora  latest      750037c05cfe  3 months ago    159 MB
# run container

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

e8f0abf6f049d677988eff3d14a7a473248f43eb7f4d581b4732eff46d043ff8
[root@dlp ~]#
podman ps 

CONTAINER ID  IMAGE                          COMMAND               CREATED         STATUS             PORTS               NAMES
e8f0abf6f049  srv.world/fedora-nginx:latest  /usr/sbin/nginx -...  11 seconds ago  Up 11 seconds ago  0.0.0.0:80->80/tcp  exciting_mcnulty
# 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": "10.88.0.10",
                         "IPAddress": "10.88.0.10",
[root@dlp ~]#
curl 10.88.0.10

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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