5.13. Exporting and importing containers

Procedure

1. Run the myubi container based on the registry.access.redhat.com/ubi10/ubi image:

   $ podman run -dt --name=myubi registry.access.redhat.com/10/ubi

2. Optional: List all containers:

   $ podman ps -a
   CONTAINER ID  IMAGE                                    COMMAND          CREATED     STATUS         PORTS   NAMES
   a6a6d4896142  registry.access.redhat.com/10:latest   /bin/bash        7 seconds ago  Up 7 seconds ago          myubi

3. Attach to the myubi container:

   $ podman attach myubi

4. Create a file named testfile:

   [root@a6a6d4896142 /]# echo "hello" > testfile

5. Detach from the container with CTRL+p and CTRL+q.

6. Export the file system of the myubi as a myubi-container.tar on the local machine:

   $ podman export -o myubi.tar a6a6d4896142

7. Optional: List the current directory content:

   $ ls -l
   -rw-r--r--. 1 user user 210885120 Apr  6 10:50 myubi-container.tar
   ...

8. Optional: Create a myubi-container directory, extract all files from the myubi-container.tar archive. List a content of the myubi-directory in a tree-like format:

   $ mkdir myubi-container
   $ tar -xf myubi-container.tar -C myubi-container
   $ tree -L 1 myubi-container
   ├── bin -> usr/bin
   ├── boot
   ├── dev
   ├── etc
   ├── home
   ├── lib -> usr/lib
   ├── lib64 -> usr/lib64
   ├── lost+found
   ├── media
   ├── mnt
   ├── opt
   ├── proc
   ├── root
   ├── run
   ├── sbin -> usr/sbin
   ├── srv
   ├── sys
   ├── testfile
   ├── tmp
   ├── usr
   └── var
   
   20 directories, 1 file

   You can see that the myubi-container.tar contains the container file system.

9. Import the myubi.tar and saves it as a filesystem image:

   $ podman import myubi.tar myubi-imported
   Getting image source signatures
   Copying blob 277cab30fe96 done
   Copying config c296689a17 done
   Writing manifest to image destination
   Storing signatures
   c296689a17da2f33bf9d16071911636d7ce4d63f329741db679c3f41537e7cbf

10. List all images:

    $ podman images
    REPOSITORY                              TAG     IMAGE ID      CREATED         SIZE
    docker.io/library/myubi-imported       latest  c296689a17da  51 seconds ago  211 MB

11. Display the content of the testfile file:

    $ podman run -it --name=myubi-imported myubi-imported cat testfile
    hello

    For more information, see the podman-export (1) and podman-import(1) man pages on your system.