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Diffstat (limited to 'troubleshooting.md')
| -rw-r--r-- | troubleshooting.md | 70 |
1 files changed, 51 insertions, 19 deletions
diff --git a/troubleshooting.md b/troubleshooting.md index da7a9cb6a..ea85df58a 100644 --- a/troubleshooting.md +++ b/troubleshooting.md @@ -16,7 +16,39 @@ If they differ, please update your version of PODMAN to the latest possible and retry your command before reporting the issue. --- -### 2) No such image or Bare keys cannot contain ':' +### 2) Can't use volume mount, get permission denied + +$ podman run -v ~/mycontent:/content fedora touch /content/file +touch: cannot touch '/content/file': Permission denied + +#### Solution + +This is usually caused by SELinux. + +Labeling systems like SELinux require that proper labels are placed on volume +content mounted into a container. Without a label, the security system might +prevent the processes running inside the container from using the content. By +default, Podman does not change the labels set by the OS. + +To change a label in the container context, you can add either of two suffixes +**:z** or **:Z** to the volume mount. These suffixes tell Podman to relabel file +objects on the shared volumes. The **z** option tells Podman that two containers +share the volume content. As a result, Podman labels the content with a shared +content label. Shared volume labels allow all containers to read/write content. +The **Z** option tells Podman to label the content with a private unshared label. +Only the current container can use a private volume. + +$ podman run -v ~/mycontent:/content:Z fedora touch /content/file + +Make sure the content is private for the container. Do not relabel system directories and content. +Relabeling system content might cause other confined services on your machine to fail. For these +types of containers we recommmend that disable SELinux separation. The option `--security-opt label=disable` +will disable SELinux separation for the container. + +$ podman run --security-opt label=disable -v ~:/home/user fedora touch /home/user/file + +--- +### 3) No such image or Bare keys cannot contain ':' When doing a `podman pull` or `podman build` command and a "common" image cannot be pulled, it is likely that the `/etc/containers/registries.conf` file is either not installed or possibly @@ -44,7 +76,7 @@ error pulling image "fedora": unable to pull fedora: error getting default regis * i.e. `registries = ['registry.fedoraproject.org', 'quay.io', 'registry.access.redhat.com']` --- -### 3) http: server gave HTTP response to HTTPS client +### 4) http: server gave HTTP response to HTTPS client When doing a Podman command such as `build`, `commit`, `pull`, or `push` to a registry, tls verification is turned on by default. If authentication is not used with @@ -70,7 +102,7 @@ communicate with a registry and not use tls verification. * I.e. `podman push --tls-verify=false alpine docker://localhost:5000/myalpine:latest` --- -### 4) Rootless: could not get runtime - database configuration mismatch +### 5) Rootless: could not get runtime - database configuration mismatch In Podman release 0.11.1, a default path for rootless containers was changed, potentially causing rootless Podman to be unable to function. The new default @@ -104,7 +136,7 @@ the first path in the error message Podman gave (in this case, `/run/user/1000/tmp`). --- -### 5) rootless containers cannot ping hosts +### 6) rootless containers cannot ping hosts When using the ping command from a non-root container, the command may fail because of a lack of privileges. @@ -132,7 +164,7 @@ To make the change persistent, you'll need to add a file in `/etc/sysctl.d` that contains `net.ipv4.ping_group_range=0 $MAX_UID`. --- -### 6) Build hangs when the Dockerfile contains the useradd command +### 7) Build hangs when the Dockerfile contains the useradd command When the Dockerfile contains a command like `RUN useradd -u 99999000 -g users newuser` the build can hang. @@ -144,7 +176,7 @@ If you are using a useradd command within a Dockerfile with a large UID/GID, it If the entry in the Dockerfile looked like: RUN useradd -u 99999000 -g users newuser then add the `--no-log-init` parameter to change it to: `RUN useradd --no-log-init -u 99999000 -g users newuser`. This option tells useradd to stop creating the lastlog file. -### 7) Permission denied when running Podman commands +### 8) Permission denied when running Podman commands When rootless Podman attempts to execute a container on a non exec home directory a permission error will be raised. @@ -174,7 +206,7 @@ cat ~/.config/containers/storage.conf mount_program = "/bin/fuse-overlayfs" ``` -### 8) Permission denied when running systemd within a Podman container +### 9) Permission denied when running systemd within a Podman container When running systemd as PID 1 inside of a container on an SELinux separated machine, it needs to write to the cgroup file system. @@ -192,7 +224,7 @@ processes to write to the cgroup file system. Turn on this boolean, on SELinux s `setsebool -P container_manage_cgroup true` -### 9) Newuidmap missing when running rootless Podman commands +### 10) Newuidmap missing when running rootless Podman commands Rootless Podman requires the newuidmap and newgidmap programs to be installed. @@ -210,7 +242,7 @@ cannot find newuidmap: exec: "newuidmap": executable file not found in $PATH Install a version of shadow-utils that includes these executables. Note RHEL7 and Centos 7 will not have support for this until RHEL7.7 is released. -### 10) rootless setup user: invalid argument +### 11) rootless setup user: invalid argument Rootless Podman requires the user running it to have a range of UIDs listed in /etc/subuid and /etc/subgid. @@ -259,7 +291,7 @@ grep johndoe /etc/subuid /etc/subgid /etc/subgid:johndoe:200000:1001 ``` -### 11) Changing the location of the Graphroot leads to permission denied +### 12) Changing the location of the Graphroot leads to permission denied When I change the graphroot storage location in storage.conf, the next time I run Podman I get an error like: @@ -298,7 +330,7 @@ tells SELinux to apply the labels to the actual content. Now all new content created in these directories will automatically be created with the correct label. -### 12) Anonymous image pull fails with 'invalid username/password' +### 13) Anonymous image pull fails with 'invalid username/password' Pulling an anonymous image that doesn't require authentication can result in an `invalid username/password` error. @@ -324,7 +356,7 @@ are established locally and then the password is updated later in the container Depending upon which container tool was used to establish the credentials, use `podman logout` or `docker logout` to remove the credentials from the authentication file. -### 13) Running Podman inside a container causes container crashes and inconsistent states +### 14) Running Podman inside a container causes container crashes and inconsistent states Running Podman in a container and forwarding some, but not all, of the required host directories can cause inconsistent container behavior. @@ -342,7 +374,7 @@ This can cause Podman to reset container states and lose track of running contai For running containers on the host from inside a container, we also recommend the [Podman remote client](remote_client.md), which only requires a single socket to be mounted into the container. -### 14) Rootless 'podman build' fails EPERM on NFS: +### 15) Rootless 'podman build' fails EPERM on NFS: NFS enforces file creation on different UIDs on the server side and does not understand user namespace, which rootless Podman requires. When a container root process like YUM attempts to create a file owned by a different UID, NFS Server denies the creation. @@ -362,7 +394,7 @@ Choose one of the following: * Edit `~/.config/containers/libpod.conf` and point the `volume_path` option to that local directory. * Otherwise just run Podman as root, via `sudo podman` -### 15) Rootless 'podman build' fails when using OverlayFS: +### 16) Rootless 'podman build' fails when using OverlayFS: The Overlay file system (OverlayFS) requires the ability to call the `mknod` command when creating whiteout files when extracting an image. However, a rootless user does not have the privileges to use `mknod` in this capacity. @@ -392,7 +424,7 @@ Choose one of the following: * Install the fuse-overlayfs package for your Linux Distribution. * Add `mount_program = "/usr/bin/fuse-overlayfs"` under `[storage.options]` in your `~/.config/containers/storage.conf` file. -### 16) rhel7-init based images don't work with cgroups v2 +### 17) rhel7-init based images don't work with cgroups v2 The systemd version shipped in rhel7-init doesn't have support for cgroups v2. You'll need at least systemd 230. @@ -411,7 +443,7 @@ You'll need to either: * configure the host to use cgroups v1 * update the image to use an updated version of systemd. -### 17) rootless containers exit once the user session exits +### 18) rootless containers exit once the user session exits You need to set lingering mode through loginctl to prevent user processes to be killed once the user session completed. @@ -429,7 +461,7 @@ or as root if your user has not enough privileges. * sudo loginctl enable-linger $UID -### 18) `podman run` fails with "bpf create: permission denied error" +### 19) `podman run` fails with "bpf create: permission denied error" The Kernel Lockdown patches deny eBPF programs when Secure Boot is enabled in the BIOS. [Matthew Garrett's post](https://mjg59.dreamwidth.org/50577.html) describes the relationship between Lockdown and Secure Boot and [Jan-Philip Gehrcke's](https://gehrcke.de/2019/09/running-an-ebpf-program-may-require-lifting-the-kernel-lockdown/) connects this with eBPF. [RH bug 1768125](https://bugzilla.redhat.com/show_bug.cgi?id=1768125) contains some additional details. @@ -443,7 +475,7 @@ Attempts to run podman result in One workaround is to disable Secure Boot in your BIOS. -### 19) error creating libpod runtime: there might not be enough IDs available in the namespace +### 20) error creating libpod runtime: there might not be enough IDs available in the namespace Unable to pull images @@ -470,7 +502,7 @@ $ podman unshare cat /proc/self/uid_map Reference [subuid](http://man7.org/linux/man-pages/man5/subuid.5.html) and [subgid](http://man7.org/linux/man-pages/man5/subgid.5.html) man pages for more detail. -### 20) Passed-in device can't be accessed in rootless container +### 21) Passed-in device can't be accessed in rootless container As a non-root user you have group access rights to a device that you want to pass into a rootless container with `--device=...`. |