How to use the command 'podman build' (with examples)
This article provides examples of how to use the podman build command, which is a daemonless tool for building container images. Podman is a Docker-CLI comparable command-line interface where alias docker=podman can be used. The command is used to create container images based on a Dockerfile or a Containerfile.
Use case 1: Create an image using a Dockerfile or Containerfile in the specified directory
Code:
podman build path/to/directory
Motivation: This use case is helpful when you want to create a container image by utilizing a Dockerfile or a Containerfile present in a specific directory.
Explanation: The command podman build is followed by the path to the directory containing the Dockerfile or the Containerfile. This allows Podman to build a container image based on the instructions provided in the file.
Example output:
STEP 1/5: FROM alpine:latest
...
STEP 5/5: CMD ["/bin/hello-world"]
Successfully built c3fdab067515
Use case 2: Create an image with a specified tag
Code:
podman build --tag image_name:version path/to/directory
Motivation: Specifying a tag for the image is useful for organizing and identifying different versions of the same image.
Explanation: The --tag or -t option is used to provide a name and tag for the image being built. The format for the tag is image_name:version. This allows the user to easily recognize and reference the image in the future.
Example output:
STEP 1/5: FROM alpine:latest
...
STEP 5/5: CMD ["/bin/hello-world"]
Successfully built c3fdab067515
Use case 3: Create an image from a non-standard file
Code:
podman build --file Containerfile.different .
Motivation: This use case is handy when you want to create an image using a file with a name other than the standard Dockerfile or Containerfile.
Explanation: The --file option is used to specify the name of the file to be used for building the image. In this example, Containerfile.different is used instead of the default Dockerfile or Containerfile. The dot (.) represents the current directory.
Example output:
STEP 1/5: FROM alpine:latest
...
STEP 5/5: CMD ["/bin/hello-world"]
Successfully built c3fdab067515
Use case 4: Create an image without using any previously cached images
Code:
podman build --no-cache path/to/directory
Motivation: Sometimes it is necessary to rebuild an image from scratch without relying on any previously cached layers or images. This use case ensures a clean build.
Explanation: The --no-cache option is used to instruct Podman to perform a build without using any previously cached images or layers. This forces Podman to rebuild the image completely.
Example output:
STEP 1/5: FROM alpine:latest
...
STEP 5/5: CMD ["/bin/hello-world"]
Successfully built c3fdab067515
Use case 5: Create an image suppressing all output
Code:
podman build --quiet path/to/directory
Motivation: Suppressing all output can be useful when you only need to know if the build was successful or not, without being flooded with unnecessary information.
Explanation: The --quiet or -q option is used to suppress all output during the image building process. Only errors and the final result will be displayed.
Example output:
Successfully built c3fdab067515
Conclusion:
The podman build command provides an efficient way to build container images using various options and configurations. By following the provided examples, users can create images from Dockerfiles or Containerfiles, customize image tags, use non-standard file names, rebuild images from scratch, and suppress output as needed. These features make Podman a versatile tool for image creation and management.
