This content originally appeared on DEV Community and was authored by Wycliffe A. Onyango
Testing Containerized Application Features
To begin testing new containerized application features for the Nautilus project, the DevOps team was tasked with preparing a specific Docker image on App Server 3. The plan was to use a busybox:musl image and re-tag it for the new project.
Step 1: Pull the Busybox Image
The first action was to download the busybox:musl image from Docker Hub using the docker pull command. This ensures the required image is available on the local server.
[banner@stapp03 ~]$ docker pull busybox:musl
musl: Pulling from library/busybox
8e7bef4a92af: Pull complete
Digest: sha256:254e6134b1bf813b34e920bc4235864a54079057d51ae6db9a4f2328f261c2ad
Status: Downloaded newer image for busybox:musl
docker.io/library/busybox:musl
Once the download was complete, the docker images command was used to verify that the image was successfully added to the server’s local repository.
[banner@stapp03 ~]$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
busybox musl 44f1048931f5 11 months ago 1.46MB
Step 2: Re-tag the Image
The next step was to create a new tag for the image, specifically busybox:media. The docker tag command is used for this purpose. This command creates a new tag that points to the same underlying image, identified by its IMAGE ID.
[banner@stapp03 ~]$ docker tag busybox:musl busybox:media
To confirm that the re-tagging was successful, the docker images command was run again. The output now shows two tags for the same IMAGE ID, indicating the task is complete.
[banner@stapp03 ~]$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
busybox media 44f1048931f5 11 months ago 1.46MB
busybox musl 44f1048931f5 11 months ago 1.46MB
This content originally appeared on DEV Community and was authored by Wycliffe A. Onyango