podman snippet

podman

不同用户下执行 podman ps，只能查看当前用户的运行容器（即使是root用户，也不能查看其他普通用户启用的容器信息）

command

overview

1
2
3
4
5
# check disk usage
podman system df

# debug command 
podman --log-level=debug xxx

image

1
2
# load tar file to image
podman load -i <image-tar-file>

prune

1
2
3
4
5
6
7
8
# remove unused containers (stopped containers)
podman container prune

# delete dangling images (images not referenced by any container)
podman image prune

# comprehensive cleanup (all unused containers, images, pods, and optionally volumes)
podman system prune -a

best practices

change default data dir

  • rootful mode

    Default graphroot: /var/lib/containers/storage.

1
2
3
4
5
6
7
8
9
10
11
# check
podman info | grep 'GraphRoot'

# Edit Podman’s Storage Configuration
sudo mkdir -p /etc/containers
sudo vim /etc/containers/storage.conf # root用户默认采用的配置

# edit storage.conf
[storage]
driver = "overlay"
graphroot = "/mnt/podman-root-data"

  • rootless mode

    Default graphroot: ~/.local/share/containers/storage.

1
2
3
4
5
6
7
8
9
10
11
12
# check
podman info | grep 'GraphRoot'

# Edit Podman’s Storage Configuration
mkdir -p ~/.config/containers
vim ~/.config/containers/storage.conf   # 普通用户默认采用的配置

# edit storge.conf
[storage]
driver = "overlay"
graphroot = "/mnt/podman-<userName>/data" # 普通用户和root用户的数据必须要区分开，不然会有目录权限操作的问题
runroot = "/mnt/podman-<userName>/run"

troubleshooting

potentially insufficient UIDs or GIDs available in user namespace

If the requested UID/GID still falls outside or Podman needs more mappings, you can edit /etc/subuid and /etc/subgid (as root) to increase the range

1
2
3
4
5
6
# Increase UID/GID Range (Optional):
sudo vim /etc/subuid  # dingofs:60000:131072
sudo vim /etc/subgid  # dingofs:60000:131072

# use current regular user, e.g. dingofs
podman system migrate

Error: creating events dirs: mkdir /run/user/1001: permission denied

1
2
3
4
5
# edit ~/.bashrc or ~/.zshrc
export XDG_RUNTIME_DIR=/run/user/$(id -u)

# available
source ~/.bashrc

error while loading shared libraries

when execute ‘podman run -it –entrypoint bash xxx’, occur ‘bash: error while loading shared libraries: /usr/lib64/libc.so.6: cannot apply additional memory protection after relocation: Permission denied’

1
sudo setenforce 0

ulimit: open files: cannot modify limit: Operation not permitted

use regular use could not operate ulimit command

  1. Set ulimit when starting the container

    1
    podman run -it --ulimit nofile=1048576:1048576 your_image

  2. Adjust host user limits (Edit /etc/security/limits.conf as root)

    1
    2
    your_username soft nofile 1048576
    your_username hard nofile 1048576

Error: unable to start container “xxx”: crun: setrlimit RLIMIT_NOFILE: Operation not permitted: OCI permission denied

same with above

panic: runtime error: invalid memory address or nil pointer dereference

  • issue

    execute ‘podman system migrate’ occur issue

    1
    2
    3
    stopped 70802e06e7ae92ef5ac6cf2e90655988949f74799c088afe3589b2031e2371f7
    panic: runtime error: invalid memory address or nil pointer dereference
    [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x564e3393c85b]

  • solution

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    # check 
    echo $XDG_RUNTIME_DIR
    # If empty, set it:  export XDG_RUNTIME_DIR=/run/user/$(id -u)

    # Make sure user linger is enabled
    loginctl enable-linger $USER

    # Restart systemd user services
    systemctl --user daemon-reexec
    systemctl --user restart podman

    # Clean up rootless storage/socket
    rm -rf $XDG_RUNTIME_DIR/podman
    rm -rf $XDG_RUNTIME_DIR/libpod

    # If still stuck, consider resetting container storage:
    podman --log-level=debug system reset