noble (5) containers.conf.5.gz
NAME
containers.conf - The container engine configuration file specifies default configuration options and
command-line flags for container engines.
DESCRIPTION
Container engines like Podman & Buildah read containers.conf file, if it exists and modify the defaults
for running containers on the host. containers.conf uses a TOML format that can be easily modified and
versioned.
Container engines read the /usr/share/containers/containers.conf, /etc/containers/containers.conf, and
/etc/containers/containers.conf.d/*.conf files if they exist. When running in rootless mode, they also
read $HOME/.config/containers/containers.conf and $HOME/.config/containers/containers.conf.d/*.conf
files.
Fields specified in containers conf override the default options, as well as options in previously read
containers.conf files.
Config files in the .d directories, are added in alpha numeric sorted order and must end in .conf.
Not all options are supported in all container engines.
Note, container engines also use other configuration files for configuring the environment.
• storage.conf for configuration of container and images storage.
• registries.conf for definition of container registries to search while pulling. container
images.
• policy.conf for controlling which images can be pulled to the system.
ENVIRONMENT VARIABLES
If the CONTAINERS_CONF environment variable is set, all system and user config files are ignored and only
the specified config file will be loaded.
If the CONTAINERS_CONF_OVERRIDE path environment variable is set, the config file will be loaded last
even when CONTAINERS_CONF is set.
The values of both environment variables may be absolute or relative paths, for instance,
CONTAINERS_CONF=/tmp/my_containers.conf.
MODULES
A module is a containers.conf file located directly in or a sub-directory of the following three
directories:
- $HOME/.config/containers/containers.conf.modules
- /etc/containers/containers.conf.modules
- /usr/share/containers/containers.conf.modules
Files in those locations are not loaded by default but only on-demand. They are loaded after all system
and user configuration files but before CONTAINERS_CONF_OVERRIDE hence allowing for overriding system and
user configs.
Modules are currently supported by podman(1). The podman --module flag allows for loading a module and
can be specified multiple times. If the specified value is an absolute path, the config file will be
loaded directly. Relative paths are resolved relative to the three module directories mentioned above
and in the specified order such that modules in $HOME allow for overriding those in /etc and /usr/share.
Modules in $HOME (or $XDG_CONFIG_HOME if specified) are only used for rootless users.
APPENDING TO STRING ARRAYS
The default behavior during the loading sequence of multiple containers.conf files is to override
previous data. To change the behavior from overriding to appending, you can set the append attribute as
follows: array=["item-1", "item=2", ..., {append=true}]. Setting the append attribute instructs to
append to this specific string array for the current and also subsequent loading steps. To change back
to overriding, set {append=false}.
Consider the following example:
modules1.conf: env=["1=true"]
modules2.conf: env=["2=true"]
modules3.conf: env=["3=true", {append=true}]
modules3.conf: env=["4=true"]
After loading the files in the given order, the final contents are env=["2=true", "3=true", "4=true"].
If modules4.conf would set {append=false}, the final contents would be env=["4=true"].
FORMAT
The TOML format ⟨https://github.com/toml-lang/toml⟩ is used as the encoding of the configuration file.
Every option is nested under its table. No bare options are used. The format of TOML can be simplified
to:
[table1]
option = value
[table2]
option = value
[table3]
option = value
[table3.subtable1]
option = value
CONTAINERS TABLE
The containers table contains settings to configure and manage the OCI runtime.
annotations = []
List of annotations. Specified as "key=value" pairs to be added to all containers.
Example: "run.oci.keep_original_groups=1"
apparmor_profile="container-default"
Used to change the name of the default AppArmor profile of container engines. The default profile name
is "container-default".
base_hosts_file=""
The hosts entries from the base hosts file are added to the containers hosts file. This must be either an
absolute path or as special values "image" which uses the hosts file from the container image or "none"
which means no base hosts file is used. The default is "" which will use /etc/hosts.
cgroup_conf=[]
List of cgroup_conf entries specifying a list of cgroup files to write to and their values. For example
memory.high=1073741824 sets the memory.high limit to 1GB.
cgroups="enabled"
Determines whether the container will create CGroups. Options are:
enabled Enable cgroup support within container
disabled Disable cgroup support, will inherit cgroups from parent
no-conmon Do not create a cgroup dedicated to conmon.
cgroupns="private"
Default way to to create a cgroup namespace for the container. Options are: private Create private
Cgroup Namespace for the container. host Share host Cgroup Namespace with the container.
default_capabilities=[]
List of default capabilities for containers.
The default list is:
default_capabilities = [
"CHOWN",
"DAC_OVERRIDE",
"FOWNER",
"FSETID",
"KILL",
"NET_BIND_SERVICE",
"SETFCAP",
"SETGID",
"SETPCAP",
"SETUID",
"SYS_CHROOT",
]
Note, by default container engines using containers.conf, run with less capabilities than Docker. Docker
runs additionally with "AUDIT_WRITE", "MKNOD" and "NET_RAW". If you need to add one of these capabilities
for a particular container, you can use the --cap-add option or edit your system's containers.conf.
default_sysctls=[]
A list of sysctls to be set in containers by default, specified as "name=value".
Example:"net.ipv4.ping_group_range=0 1000".
default_ulimits=[]
A list of ulimits to be set in containers by default, specified as "name=soft-limit:hard-limit".
Example: "nofile=1024:2048".
devices=[]
List of devices. Specified as 'device-on-host:device-on-container:permissions'.
Example: "/dev/sdc:/dev/xvdc:rwm".
dns_options=[]
List of default DNS options to be added to /etc/resolv.conf inside of the container.
dns_searches=[]
List of default DNS search domains to be added to /etc/resolv.conf inside of the container.
dns_servers=[]
A list of dns servers to override the DNS configuration passed to the container. The special value “none”
can be specified to disable creation of /etc/resolv.conf in the container.
env=["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"]
Environment variable list for the container process, used for passing environment variables to the
container.
env_host=false
Pass all host environment variables into the container.
host_containers_internal_ip=""
Set the ip for the host.containers.internal entry in the containers /etc/hosts file. This can be set to
"none" to disable adding this entry. By default it will automatically choose the host ip.
NOTE: When using podman machine this entry will never be added to the containers hosts file instead the
gvproxy dns resolver will resolve this hostname. Therefore it is not possible to disable the entry in
this case.
http_proxy=true
Default proxy environment variables will be passed into the container. The environment variables passed
in include: http_proxy, https_proxy, ftp_proxy, no_proxy, and the upper case versions of these. The
no_proxy option is needed when host system uses a proxy but container should not use proxy. Proxy
environment variables specified for the container in any other way will override the values passed from
the host.
init=false
Run an init inside the container that forwards signals and reaps processes.
init_path="/usr/libexec/podman/catatonit"
If this option is not set catatonit is searched in the directories listed under the helper_binaries_dir
option. It is recommended to just install catatonit there instead of configuring this option here.
Path to the container-init binary, which forwards signals and reaps processes within containers. Note
that the container-init binary will only be used when the --init for podman-create and podman-run is set.
ipcns="shareable"
Default way to to create a IPC namespace for the container. Options are:
host Share host IPC Namespace with the container.
none Create shareable IPC Namespace for the container without a private /dev/shm.
private Create private IPC Namespace for the container, other containers are not allowed to share it.
shareable Create shareable IPC Namespace for the container.
keyring=true
Indicates whether the container engines create a kernel keyring for use within the container.
label=true
Indicates whether the container engine uses MAC(SELinux) container separation via labeling. This option
is ignored on disabled systems.
label_users=false
label_users indicates whether to enforce confined users in containers on SELinux systems. This option
causes containers to maintain the current user and role field of the calling process. By default SELinux
containers run with the user system_u, and the role system_r.
log_driver=""
Logging driver for the container. Currently available options are k8s-file, journald, none and
passthrough, with json-file aliased to k8s-file for scripting compatibility. The journald driver is used
by default if the systemd journal is readable and writable. Otherwise, the k8s-file driver is used.
log_size_max=-1
Maximum size allowed for the container's log file. Negative numbers indicate that no size limit is
imposed. If it is positive, it must be >= 8192 to match/exceed conmon's read buffer. The file is
truncated and re-opened so the limit is never exceeded.
log_tag=""
Default format tag for container log messages. This is useful for creating a specific tag for container
log messages. Container log messages default to using the truncated container ID as a tag.
mounts=[]
List of mounts. Specified as "type=TYPE,source=,destination=,"
Example: [ "type=bind,source=/var/lib/foobar,destination=/var/lib/foobar,ro", ]
netns="private"
Default way to to create a NET namespace for the container. Options are:
private Create private NET Namespace for the container.
host Share host NET Namespace with the container.
none Containers do not use the network.
no_hosts=false
Create /etc/hosts for the container. By default, container engines manage /etc/hosts, automatically
adding the container's own IP address.
oom_score_adj=0
Tune the host's OOM preferences for containers (accepts values from -1000 to 1000).
pidns="private"
Default way to to create a PID namespace for the container. Options are:
private Create private PID Namespace for the container.
host Share host PID Namespace with the container.
pids_limit=1024
Maximum number of processes allowed in a container. 0 indicates that no limit is imposed.
prepare_volume_on_create=false
Copy the content from the underlying image into the newly created volume when the container is created
instead of when it is started. If false, the container engine will not copy the content until the
container is started. Setting it to true may have negative performance implications.
privileged=false
Give extended privileges to all containers. A privileged container turns off the security features that
isolate the container from the host. Dropped Capabilities, limited devices, read-only mount points,
Apparmor/SELinux separation, and Seccomp filters are all disabled. Due to the disabled security features,
the privileged field should almost never be set as containers can easily break out of confinment.
Containers running in a user namespace (e.g., rootless containers) cannot have more privileges than the
user that launched them.
read_only=true|false
Run all containers with root file system mounted read-only. Set to false by default.
seccomp_profile="/usr/share/containers/seccomp.json"
Path to the seccomp.json profile which is used as the default seccomp profile for the runtime.
shm_size="65536k"
Size of /dev/shm. The format is <number><unit>. number must be greater than 0. Unit is optional and can
be: b (bytes), k (kilobytes), m(megabytes), or g (gigabytes). If you omit the unit, the system uses
bytes. If you omit the size entirely, the system uses 65536k.
tz=""
Set timezone in container. Takes IANA timezones as well as local, which sets the timezone in the
container to match the host machine. If not set, then containers will run with the time zone specified
in the image.
Examples:
tz="local"
tz="America/New_York"
umask="0022"
Sets umask inside the container.
userns="host"
Default way to to create a USER namespace for the container. Options are:
private Create private USER Namespace for the container.
host Share host USER Namespace with the container.
utsns="private"
Default way to to create a UTS namespace for the container. Options are:
private Create private UTS Namespace for the container.
host Share host UTS Namespace with the container.
volumes=[]
List of volumes. Specified as "directory-on-host:directory-in-container:options".
Example: "/db:/var/lib/db:ro".
NETWORK TABLE
The network table contains settings pertaining to the management of CNI plugins.
network_backend=""
Network backend determines what network driver will be used to set up and tear down container networks.
Valid values are "cni" and "netavark". The default value is empty which means that it will automatically
choose CNI or netavark. If there are already containers/images or CNI networks preset it will choose CNI.
Before changing this value all containers must be stopped otherwise it is likely that iptables rules and
network interfaces might leak on the host. A reboot will fix this.
cni_plugin_dirs=[]
List of paths to directories where CNI plugin binaries are located.
The default list is:
cni_plugin_dirs = [
"/usr/local/libexec/cni",
"/usr/libexec/cni",
"/usr/local/lib/cni",
"/usr/lib/cni",
"/opt/cni/bin",
]
netavark_plugin_dirs=[]
List of directories that will be searched for netavark plugins.
The default list is:
netavark_plugin_dirs = [
"/usr/local/libexec/netavark",
"/usr/libexec/netavark",
"/usr/local/lib/netavark",
"/usr/lib/netavark",
]
default_network="podman"
The network name of the default network to attach pods to.
default_subnet="10.88.0.0/16"
The subnet to use for the default network (named above in default_network). If the default network does
not exist, it will be automatically created the first time a tool is run using this subnet.
default_subnet_pools=[]
DefaultSubnetPools is a list of subnets and size which are used to allocate subnets automatically for
podman network create. It will iterate through the list and will pick the first free subnet with the
given size. This is only used for ipv4 subnets, ipv6 subnets are always assigned randomly.
The default list is (10.89.0.0-10.255.255.0/24):
default_subnet_pools = [
{"base" = "10.89.0.0/16", "size" = 24},
{"base" = "10.90.0.0/15", "size" = 24},
{"base" = "10.92.0.0/14", "size" = 24},
{"base" = "10.96.0.0/11", "size" = 24},
{"base" = "10.128.0.0/9", "size" = 24},
]
default_rootless_network_cmd="slirp4netns"
Configure which rootless network program to use by default. Valid options are slirp4netns (default) and
pasta.
network_config_dir="/etc/cni/net.d/"
Path to the directory where network configuration files are located. For the CNI backend the default is
/etc/cni/net.d as root and $HOME/.config/cni/net.d as rootless. For the netavark backend
"/etc/containers/networks" is used as root and "$graphroot/networks" as rootless.
dns_bind_port=53
Port to use for dns forwarding daemon with netavark in rootful bridge mode and dns enabled. Using an
alternate port might be useful if other dns services should run on the machine.
pasta_options = []
A list of default pasta options that should be used running pasta. It accepts the pasta cli options, see
pasta(1) for the full list of options.
ENGINE TABLE
The engine table contains configuration options used to set up container engines such as Podman and
Buildah.
active_service=""
Name of destination for accessing the Podman service. See SERVICE DESTINATION TABLE below.
add_compression=[]
List of compression algorithms. If set makes sure that requested compression variant for each platform is
added to the manifest list keeping original instance intact in the same manifest list on every manifest
push. Supported values are (gzip, zstd and zstd:chunked).
Note: This is different from compression_format which allows users to select a default compression format
for push and manifest push, while add_compression is limited to manifest push and allows users to append
new instances to manifest list with specified compression algorithms in add_compression for each
platform.
cgroup_manager="systemd"
The cgroup management implementation used for the runtime. Supports cgroupfs and systemd.
compat_api_enforce_docker_hub=true
Enforce using docker.io for completing short names in Podman's compatibility REST API. Note that this
will ignore unqualified-search-registries and short-name aliases defined in containers-
registries.conf(5).
compose_providers=[]
Specify one or more external providers for the compose command. The first found provider is used for
execution. Can be an absolute and relative path or a (file) name.
compose_warning_logs=true
Emit logs on each invocation of the compose command indicating that an external compose provider is being
executed.
conmon_env_vars=[]
Environment variables to pass into Conmon.
conmon_path=[]
Paths to search for the conmon container manager binary. If the paths are empty or no valid path was
found, then the $PATH environment variable will be used as the fallback.
The default list is:
conmon_path=[
"/usr/libexec/podman/conmon",
"/usr/local/libexec/podman/conmon",
"/usr/local/lib/podman/conmon",
"/usr/bin/conmon",
"/usr/sbin/conmon",
"/usr/local/bin/conmon",
"/usr/local/sbin/conmon",
"/run/current-system/sw/bin/conmon",
]
database_backend=""
The database backend of Podman. Supported values are "" (default), "boltdb" and "sqlite". An empty value
means it will check whenever a boltdb already exists and use it when it does, otherwise it will use
sqlite as default (e.g. new installs). This allows for backwards compatibility with older versions.
Please run podman-system-reset prior to changing the database backend of an existing deployment, to make
sure Podman can operate correctly.
detach_keys="ctrl-p,ctrl-q"
Keys sequence used for detaching a container. Specify the keys sequence used to detach a container.
Format is a single character [a-Z] or a comma separated sequence of ctrl-<value>, where <value> is one
of: a-z, @, ^, [, \, ], ^ or _ Specifying "" disables this feature.
enable_port_reservation=true
Determines whether the engine will reserve ports on the host when they are forwarded to containers. When
enabled, when ports are forwarded to containers, they are held open by conmon as long as the container is
running, ensuring that they cannot be reused by other programs on the host. However, this can cause
significant memory usage if a container has many ports forwarded to it. Disabling this can save memory.
env=[]
Environment variables to be used when running the container engine (e.g., Podman, Buildah). For example
"http_proxy=internal.proxy.company.com". Note these environment variables will not be used within the
container. Set the env section under [containers] table, if you want to set environment variables for the
container.
events_logfile_path=""
Define where event logs will be stored, when events_logger is "file".
events_logfile_max_size="1m"
Sets the maximum size for events_logfile_path. The unit can be b (bytes), k (kilobytes), m (megabytes)
or g (gigabytes). The format for the size is <number><unit>, e.g., 1b or 3g. If no unit is included
then the size will be in bytes. When the limit is exceeded, the logfile will be rotated and the old one
will be deleted. If the maximumn size is set to 0, then no limit will be applied, and the logfile will
not be rotated.
events_logger="journald"
The default method to use when logging events.
The default method is different based on the platform that Podman is being run upon. To determine the
current value, use this command:
podman info --format {{.Host.EventLogger}
Valid values are: file, journald, and none.
events_container_create_inspect_data=true|false
Creates a more verbose container-create event which includes a JSON payload with detailed information
about the container. Set to false by default.
helper_binaries_dir=["/usr/libexec/podman", ...]
A is a list of directories which are used to search for helper binaries. The following binaries are
searched in these directories:
- aardvark-dns
- catatonit
- netavark
- pasta
- slirp4netns
Podman machine uses it for these binaries:
- gvproxy
- qemu
- vfkit
The default paths on Linux are:
• /usr/local/libexec/podman
• /usr/local/lib/podman
• /usr/libexec/podman
• /usr/lib/podman
The default paths on macOS are:
• /usr/local/opt/podman/libexec
• /opt/homebrew/bin
• /opt/homebrew/opt/podman/libexec
• /usr/local/bin
• /usr/local/libexec/podman
• /usr/local/lib/podman
• /usr/libexec/podman
• /usr/lib/podman
The default path on Windows is:
• C:\Program Files\RedHat\Podman
hooks_dir=["/etc/containers/oci/hooks.d", ...]
Path to the OCI hooks directories for automatically executed hooks.
image_default_format="oci"|"v2s2"|"v2s1"
Manifest Type (oci, v2s2, or v2s1) to use when pulling, pushing, building container images. By default
images pulled and pushed match the format of the source image. Building/committing defaults to OCI.
Note: image_build_format is deprecated.
image_default_transport="docker://"
Default transport method for pulling and pushing images.
image_parallel_copies=0
Maximum number of image layers to be copied (pulled/pushed) simultaneously. Not setting this field will
fall back to containers/image defaults. (6)
image_volume_mode="bind"
Tells container engines how to handle the built-in image volumes.
• bind: An anonymous named volume will be created and mounted into the container.
• tmpfs: The volume is mounted onto the container as a tmpfs, which allows the users to create
content that disappears when the container is stopped.
• ignore: All volumes are just ignored and no action is taken.
infra_command="/pause"
Infra (pause) container image command for pod infra containers. When running a pod, we start a /pause
process in a container to hold open the namespaces associated with the pod. This container does nothing
other than sleep, reserving the pod's resources for the lifetime of the pod.
infra_image=""
Infra (pause) container image for pod infra containers. When running a pod, we start a pause process in a
container to hold open the namespaces associated with the pod. This container does nothing other than
sleep, reserving the pod's resources for the lifetime of the pod. By default container engines run a
built-in container using the pause executable. If you want override specify an image to pull.
kube_generate_type="pod"
Default Kubernetes kind/specification of the kubernetes yaml generated with the podman kube generate
command. The possible options are pod and deployment.
lock_type="shm"
Specify the locking mechanism to use; valid values are "shm" and "file". Change the default only if you
are sure of what you are doing, in general "file" is useful only on platforms where cgo is not available
for using the faster "shm" lock type. You may need to run "podman system renumber" after you change the
lock type.
multi_image_archive=false
Allows for creating archives (e.g., tarballs) with more than one image. Some container engines, such as
Podman, interpret additional arguments as tags for one image and hence do not store more than one image.
The default behavior can be altered with this option.
namespace=""
Default engine namespace. If the engine is joined to a namespace, it will see only containers and pods
that were created in the same namespace, and will create new containers and pods in that namespace. The
default namespace is "", which corresponds to no namespace. When no namespace is set, all containers and
pods are visible.
network_cmd_path=""
Path to the slirp4netns binary.
network_cmd_options=[]
Default options to pass to the slirp4netns binary.
Valid options values are:
• allow_host_loopback=true|false: Allow the slirp4netns to reach the host loopback IP (10.0.2.2).
Default is false.
• mtu=MTU: Specify the MTU to use for this network. (Default is 65520).
• cidr=CIDR: Specify ip range to use for this network. (Default is 10.0.2.0/24).
• enable_ipv6=true|false: Enable IPv6. Default is true. (Required for outbound_addr6).
• outbound_addr=INTERFACE: Specify the outbound interface slirp should bind to (ipv4 traffic
only).
• outbound_addr=IPv4: Specify the outbound ipv4 address slirp should bind to.
• outbound_addr6=INTERFACE: Specify the outbound interface slirp should bind to (ipv6 traffic
only).
• outbound_addr6=IPv6: Specify the outbound ipv6 address slirp should bind to.
• port_handler=rootlesskit: Use rootlesskit for port forwarding. Default. Note: Rootlesskit
changes the source IP address of incoming packets to a IP address in the container network
namespace, usually 10.0.2.100. If your application requires the real source IP address, e.g. web
server logs, use the slirp4netns port handler. The rootlesskit port handler is also used for
rootless containers when connected to user-defined networks.
• port_handler=slirp4netns: Use the slirp4netns port forwarding, it is slower than rootlesskit but
preserves the correct source IP address. This port handler cannot be used for user-defined
networks.
no_pivot_root=false
Whether to use chroot instead of pivot_root in the runtime.
num_locks=2048
Number of locks available for containers and pods. Each created container or pod consumes one lock. The
default number available is 2048. If this is changed, a lock renumbering must be performed, using the
podman system renumber command.
pod_exit_policy="continue"
Set the exit policy of the pod when the last container exits. Supported policies are:
┌────────────┬───────────────────────────────────────┐
│Exit Policy │ Description │
├────────────┼───────────────────────────────────────┤
│continue │ The pod continues running when the │
│ │ last container exits. Used by │
│ │ default. │
├────────────┼───────────────────────────────────────┤
│stop │ The pod is stopped when the last │
│ │ container exits. Used in play kube. │
└────────────┴───────────────────────────────────────┘
pull_policy="always"|"missing"|"never"
Pull image before running or creating a container. The default is missing.
• missing: attempt to pull the latest image from the registries listed in registries.conf if a
local image does not exist. Raise an error if the image is not in any listed registry and is not
present locally.
• always: pull the image from the first registry it is found in as listed in registries.conf.
Raise an error if not found in the registries, even if the image is present locally.
• never: do not pull the image from the registry, use only the local version. Raise an error if
the image is not present locally.
remote = false
Indicates whether the application should be running in remote mode. This flag modifies the --remote
option on container engines. Setting the flag to true will default podman --remote=true for access to the
remote Podman service.
runtime=""
Default OCI specific runtime in runtimes that will be used by default. Must refer to a member of the
runtimes table. Default runtime will be searched for on the system using the priority: "crun", "runc",
"kata".
runtime_supports_json=["crun", "runc", "kata", "runsc", "youki", "krun"]
The list of the OCI runtimes that support --format=json.
runtime_supports_kvm=["kata", "krun"]
The list of OCI runtimes that support running containers with KVM separation.
runtime_supports_nocgroups=["crun", "krun"]
The list of OCI runtimes that support running containers without CGroups.
image_copy_tmp_dir="/var/tmp"
Default location for storing temporary container image content. Can be overridden with the TMPDIR
environment variable. If you specify "storage", then the location of the container/storage tmp directory
will be used. If set then it is the users responsibility to cleanup storage. Configure tmpfiles.d(5) to
cleanup storage.
service_timeout=5
Number of seconds to wait without a connection before the podman system service times out and exits
static_dir="/var/lib/containers/storage/libpod"
Directory for persistent libpod files (database, etc). By default this will be configured relative to
where containers/storage stores containers.
stop_timeout=10
Number of seconds to wait for container to exit before sending kill signal.
exit_command_delay=300
Number of seconds to wait for the API process for the exec call before sending exit command mimicking the
Docker behavior of 5 minutes (in seconds).
tmp_dir="/run/libpod"
The path to a temporary directory to store per-boot container. Must be a tmpfs (wiped after reboot).
volume_path="/var/lib/containers/storage/volumes"
Directory where named volumes will be created in using the default volume driver. By default this will
be configured relative to where containers/storage store containers. This convention is followed by the
default volume driver, but may not be by other drivers.
chown_copied_files=true
Determines whether file copied into a container will have changed ownership to the primary uid/gid of the
container.
compression_format="gzip"
Specifies the compression format to use when pushing an image. Supported values are: gzip, zstd and
zstd:chunked.
compression_level="5"
The compression level to use when pushing an image. Valid options depend on the compression format used.
For gzip, valid options are 1-9, with a default of 5. For zstd, valid options are 1-20, with a default of
3.
podmansh_timeout=30
Number of seconds to wait for podmansh logins.
SERVICE DESTINATION TABLE
The engine.service_destinations table contains configuration options used to set up remote connections to
the podman service for the podman API.
[engine.service_destinations.{name}] URI to access the Podman service
uri="ssh://user@production.example.com/run/user/1001/podman/podman.sock"
Example URIs:
• rootless local - unix:///run/user/1000/podman/podman.sock
• rootless remote - ssh://user@engineering.lab.company.com/run/user/1000/podman/podman.sock
• rootful local - unix:///run/podman/podman.sock
• rootful remote - ssh://root@10.10.1.136:22/run/podman/podman.sock
identity="~/.ssh/id_rsa
Path to file containing ssh identity key
[engine.volume_plugins]
A table of all the enabled volume plugins on the system. Volume plugins can be used as the backend for
Podman named volumes. Individual plugins are specified below, as a map of the plugin name (what the
plugin will be called) to its path (filepath of the plugin's unix socket).
[engine.platform_to_oci_runtime]
Allows end users to switch the OCI runtime on the bases of container image's platform string. Following
config field contains a map of platform/string = oci_runtime.
SECRET TABLE
The secret table contains settings for the configuration of the secret subsystem.
driver=file
Name of the secret driver to be used. Currently valid values are:
* file
* pass
[secrets.opts]
The driver specific options object.
MACHINE TABLE
The machine table contains configurations for podman machine VMs
cpus=1 Number of CPU's a machine is created with.
disk_size=10
The size of the disk in GB created when init-ing a podman-machine VM
image=""
Default image URI when creating a new VM using podman machine init. Options: On Linux/Mac, testing,
stable, next. On Windows, the major version of the OS (e.g 36) for Fedora 36. For all platforms you can
alternatively specify a custom download URL to an image. Container engines translate URIs $OS and $ARCH
to the native OS and ARCH. URI "https://example.com/$OS/$ARCH/foobar.ami" would become
"https://example.com/linux/amd64/foobar.ami" on a Linux AMD machine. The default value is testing on
Linux/Mac, and on Windows.
memory=2048
Memory in MB a machine is created with.
user=""
Username to use and create on the podman machine OS for rootless container access. The default value is
user. On Linux/Mac the default iscore.
volumes=["$HOME:$HOME"]
Host directories to be mounted as volumes into the VM by default. Environment variables like $HOME as
well as complete paths are supported for the source and destination. An optional third field :ro can be
used to tell the container engines to mount the volume readonly.
On Mac, the default volumes are:
[ "/Users:/Users", "/private:/private", "/var/folders:/var/folders" ]
provider=""
Virtualization provider to be used for running a podman-machine VM. Empty value is interpreted as the
default provider for the current host OS. On Linux/Mac default is QEMU and on Windows it is WSL.
FARMS TABLE
The farms table contains configuration options used to group up remote connections into farms that will
be used when sending out builds to different machines in a farm via podman buildfarm.
default=""
The default farm to use when farming out builds.
[farms.list]
Map of farms created where the key is the farm name and the value is the list of system connections.
FILES
containers.conf
Distributions often provide a /usr/share/containers/containers.conf file to provide a default
configuration. Administrators can override fields in this file by creating
/etc/containers/containers.conf to specify their own configuration. They may also drop .conf files in
/etc/containers/containers.conf.d which will be loaded in alphanumeric order. Rootless users can further
override fields in the config by creating a config file stored in the
$HOME/.config/containers/containers.conf file or .conf files in
$HOME/.config/containers/containers.conf.d.
Fields specified in a containers.conf file override the default options, as well as options in previously
loaded containers.conf files.
storage.conf
The /etc/containers/storage.conf file is the default storage configuration file. Rootless users can
override fields in the storage config by creating $HOME/.config/containers/storage.conf.
If the CONTAINERS_STORAGE_CONF path environment variable is set, this path is used for the storage.conf
file rather than the default. This is primarily used for testing.
SEE ALSO
containers-storage.conf(5), containers-policy.json(5), containers-registries.conf(5), tmpfiles.d(5)