Ubuntu 26.04

Podman : Use by common users2026/05/07

 

It's possible to use Podman containers by common users.

[1] By default, sub UID/GID that are used on user name spaces are assigned to run containers.
# default name spaces number

root@dlp:~#
cat /proc/sys/user/max_user_namespaces

61617
# sub UID/GID mapping file
# 100000 to 165535 (100000 + 65536 - 1) UID are used for running processes in containers on [ubuntu] user

root@dlp:~#
cat /etc/subuid

ubuntu:100000:65536
root@dlp:~#
cat /etc/subgid

ubuntu:100000:65536
# when added new users, sub UID/GID are also added
# n=0, n++
# [start UID/GID = 100000 + (65536 * n)]
# [end UID/GID = (start UID/GID) + 65536 - 1]

root@dlp:~#
useradd resolute

root@dlp:~#
useradd raccoon

root@dlp:~#
cat /etc/subgid /etc/subgid

ubuntu:100000:65536
resolute:165536:65536
raccoon:231072:65536
ubuntu:100000:65536
resolute:165536:65536
raccoon:231072:65536
[2] It's possible to run [podman] by common users.
ubuntu@dlp:~$
podman pull ubuntu

ubuntu@dlp:~$
podman images

REPOSITORY                TAG         IMAGE ID      CREATED      SIZE
docker.io/library/ubuntu  latest      30ba44506a6d  2 weeks ago  111 MB

ubuntu@dlp:~$
podman run ubuntu echo "run rootless containers"

run rootless containers
# containers related files are located under the [$HOME/.local] directory

ubuntu@dlp:~$
ll ~/.local/share/containers/storage

total 168
drwx------ 9 ubuntu ubuntu   4096 May  7 01:02 ./
drwx------ 4 ubuntu ubuntu   4096 May  7 00:58 ../
-rw-r--r-- 1 ubuntu ubuntu 126976 May  7 01:02 db.sql
-rw-r--r-- 1 ubuntu ubuntu      8 May  7 00:58 defaultNetworkBackend
drwx------ 2 ubuntu ubuntu   4096 May  7 00:58 libpod/
drwx------ 2 ubuntu ubuntu   4096 May  7 00:58 networks/
drwx------ 6 ubuntu ubuntu   4096 May  7 01:02 overlay/
drwx------ 3 ubuntu ubuntu   4096 May  7 01:02 overlay-containers/
drwx------ 3 ubuntu ubuntu   4096 May  7 00:58 overlay-images/
drwx------ 2 ubuntu ubuntu   4096 May  7 01:02 overlay-layers/
-rw-r--r-- 1 ubuntu ubuntu     64 May  7 01:02 storage.lock
-rw-r--r-- 1 ubuntu ubuntu      0 May  7 00:58 userns.lock
drwx------ 2 ubuntu ubuntu   4096 May  7 00:58 volumes/

# possible to create Pods

ubuntu@dlp:~$
podman pod create -p 8081:80 -n test-pod

ubuntu@dlp:~$
podman pod ls

POD ID        NAME        STATUS      CREATED        INFRA ID      # OF CONTAINERS
b214e57bf970  test-pod    Created     3 seconds ago  4a3c790da7bb  1

# for port mapping,
# it's impossible to use less than [1024] ports on Host machine by common users
# possible to use over [1024] ports

ubuntu@dlp:~$
podman run -itd -p 1023:80 ubuntu /bin/bash

Error: pasta failed with exit code 1:
Listen failed for HOST TCP port */1023: Permission denied
Couldn't listen on requested TCP ports
ubuntu@dlp:~$
podman run -itd -p 1024:80 ubuntu /bin/bash

ubuntu@dlp:~$
podman ps

CONTAINER ID  IMAGE                            COMMAND     CREATED        STATUS        PORTS                 NAMES
8f62109469b6  docker.io/library/ubuntu:latest  /bin/bash   3 seconds ago  Up 4 seconds  0.0.0.0:1024->80/tcp  peaceful_maxwell
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