buildah-run man page
buildah-run — Run a command inside of the container.
buildah run [options] [--] container command
Launches a container and runs the specified command in that container using the container's root filesystem as a root filesystem, using configuration settings inherited from the container's image or as specified using previous calls to the buildah config command. To execute buildah run within an interactive shell, specify the --tty option.
- Add an entry to the history which will note what command is being invoked. Defaults to false.
Note: You can also override the default value of --add-history by setting the BUILDAH_HISTORY environment variable.
- Add the specified capability to the set of capabilities which will be granted to the specified command. Certain capabilities are granted by default; this option can be used to add more beyond the defaults, which may have been modified by --cap-add and --cap-drop options used with the buildah from invocation which created the container.
- Add the specified capability from the set of capabilities which will be granted to the specified command. The CAP_AUDIT_WRITE, CAP_CHOWN, CAP_DAC_OVERRIDE, CAP_FOWNER, CAP_FSETID, CAP_KILL, CAP_MKNOD, CAP_NET_BIND_SERVICE, CAP_SETFCAP, CAP_SETGID, CAP_SETPCAP, CAP_SETUID, and CAP_SYS_CHROOT capabilities are granted by default; this option can be used to remove them from the defaults, which may have been modified by --cap-add and --cap-drop options used with the buildah from invocation which created the container.
If a capability is specified to both the --cap-add and --cap-drop options, it will be dropped, regardless of the order in which the options were given.
- Location of CNI configuration files which will dictate which plugins will be used to configure network interfaces and routing inside the running container, if the container will be run in its own network namespace, and networking is not disabled.
- List of directories in which the CNI plugins which will be used for configuring network namespaces can be found.
- Set the hostname inside of the running container.
- --ipc how
- Sets the configuration for the IPC namespaces for the container. The configured value can be "" (the empty string) or "container" to indicate that a new IPC namespace should be created, or it can be "host" to indicate that the IPC namespace in which
buildahitself is being run should be reused, or it can be the path to an IPC namespace which is already in use by another process.
- --isolation type
- Controls what type of isolation is used for running the process. Recognized types include oci (OCI-compatible runtime, the default), rootless (OCI-compatible runtime invoked using a modified configuration, with --no-new-keyring added to its create invocation, with network and UTS namespaces disabled, and IPC, PID, and user namespaces enabled; the default for unprivileged users), and chroot (an internal wrapper that leans more toward chroot(1) than container technology).
Note: You can also override the default isolation type by setting the BUILDAH_ISOLATION environment variable.
- --net how --network how
- Sets the configuration for the network namespace for the container. The configured value can be "" (the empty string) or "container" to indicate that a new network namespace should be created, or it can be "host" to indicate that the network namespace in which
buildahitself is being run should be reused, or it can be the path to a network namespace which is already in use by another process.
- --pid how
- Sets the configuration for the PID namespace for the container. The configured value can be "" (the empty string) or "container" to indicate that a new PID namespace should be created, or it can be "host" to indicate that the PID namespace in which
buildahitself is being run should be reused, or it can be the path to a PID namespace which is already in use by another process.
- --runtime path
- The path to an alternate OCI-compatible runtime. Default is runc.
Note: You can also override the default runtime by setting the BUILDAH_RUNTIME environment variable.
- --runtime-flag flag
- Adds global flags for the container runtime. To list the supported flags, please consult the manpages of the selected container runtime (
runcis the default runtime, the manpage to consult is
runc(8)). Note: Do not pass the leading
--to the flag. To pass the runc flag
--log-format jsonto buildah run, the option given would be
- Do not use pivot root to jail process inside rootfs. This should be used whenever the rootfs is on top of a ramdisk.
Note: You can make this option the default by setting the BUILDAH_NOPIVOT environment variable.
- -t, --tty, --terminal
- By default a pseudo-TTY is allocated only when buildah's standard input is attached to a pseudo-TTY. Setting the
truewill cause a pseudo-TTY to be allocated inside the container connecting the user's "terminal" with the stdin and stdout stream of the container. Setting the
falsewill prevent the pseudo-TTY from being allocated.
- --user user[:group]
- Set the user to be used for running the command in the container. The user can be specified as a user name or UID, optionally followed by a group name or GID, separated by a colon (':'). If names are used, the container should include entries for those names in its /etc/passwd and /etc/group files.
- --uts how
- Sets the configuration for the UTS namespace for the container. The configured value can be "" (the empty string) or "container" to indicate that a new UTS namespace should be created, or it can be "host" to indicate that the UTS namespace in which
buildahitself is being run should be reused, or it can be the path to a UTS namespace which is already in use by another process.
- --volume, -v source:destination:options
- Create a bind mount. If you specify,
-v /HOST-DIR:/CONTAINER-DIR, Buildah bind mounts
/HOST-DIRin the host to
/CONTAINER-DIRin the Buildah container. The
OPTIONSare a comma delimited list and can be:
CONTAINER-DIR must be an absolute path such as
HOST-DIR must be an absolute path as well. Buildah bind-mounts the
HOST-DIR to the path you specify. For example, if you supply
/foo as the host path, Buildah copies the contents of
/foo to the container filesystem on the host and bind mounts that into the container.
You can specify multiple -v options to mount one or more mounts to a container.
You can add the
:rw suffix to a volume to mount it read-only or read-write mode, respectively. By default, the volumes are mounted read-write. See examples.
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, Buildah 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 to the volume mount. These suffixes tell Buildah to relabel file objects on the shared volumes. The
z option tells Buildah that two containers share the volume content. As a result, Buildah labels the content with a shared content label. Shared volume labels allow all containers to read/write content. The
Z option tells Buildah to label the content with a private unshared label. Only the current container can use a private volume.
By default bind mounted volumes are
private. That means any mounts done inside container will not be visible on the host and vice versa. This behavior can be changed by specifying a volume mount propagation property.
When the mount propagation policy is set to
shared, any mounts completed inside the container on that volume will be visible to both the host and container. When the mount propagation policy is set to
slave, one way mount propagation is enabled and any mounts completed on the host for that volume will be visible only inside of the container. To control the mount propagation property of the volume use the
:[r]private propagation flag. The propagation property can be specified only for bind mounted volumes and not for internal volumes or named volumes. For mount propagation to work on the source mount point (the mount point where source dir is mounted on) it has to have the right propagation properties. For shared volumes, the source mount point has to be shared. And for slave volumes, the source mount has to be either shared or slave.
df <source-dir> to determine the source mount and then use
findmnt -o TARGET,PROPAGATION <source-mount-dir> to determine propagation properties of source mount, if
findmnt utility is not available, the source mount point can be determined by looking at the mount entry in
/proc/self/mountinfo. Look at
optional fields and see if any propagaion properties are specified.
shared:X means the mount is
master:X means the mount is
slave and if nothing is there that means the mount is
To change propagation properties of a mount point use the
mount command. For example, to bind mount the source directory
mount --bind /foo /foo and
mount --make-private --make-shared /foo. This will convert /foo into a
shared mount point. The propagation properties of the source mount can be changed directly. For instance if
/ is the source mount for
/foo, then use
mount --make-shared / to convert
/ into a
NOTE: End parsing of options with the
-- option, so that other options can be passed to the command inside of the container.
buildah run containerID -- ps -auxw
buildah run --hostname myhost containerID -- ps -auxw
buildah run containerID -- sh -c 'echo $PATH'
buildah run --runtime-flag log-format=json containerID /bin/bash
buildah run --runtime-flag debug containerID /bin/bash
buildah run --tty containerID /bin/bash
buildah run --tty=false containerID ls /
buildah run --volume /path/on/host:/path/in/container:ro,z containerID sh
buildah(1), namespaces(7), pid_namespaces(7)