Our intention is to make all settings that are available as unit file settings also available for transient units, through the D-Bus API. At the moment, some unit types (device, swap, target) are not supported at all via unit types, but most others are pretty well supported, with some notable omissions.
The lists below contain all settings currently available in unit files. The ones currently available in transient units are prefixed with ✓.
Most generic unit settings are available for transient units.
✓ Description= ✓ Documentation= ✓ SourcePath= ✓ Requires= ✓ Requisite= ✓ Wants= ✓ BindsTo= ✓ Conflicts= ✓ Before= ✓ After= ✓ OnFailure= ✓ PropagatesReloadTo= ✓ ReloadPropagatedFrom= ✓ PartOf= ✓ JoinsNamespaceOf= ✓ RequiresMountsFor= ✓ StopWhenUnneeded= ✓ RefuseManualStart= ✓ RefuseManualStop= ✓ AllowIsolate= ✓ DefaultDependencies= ✓ OnFailureJobMode= ✓ IgnoreOnIsolate= ✓ JobTimeoutSec= ✓ JobRunningTimeoutSec= ✓ JobTimeoutAction= ✓ JobTimeoutRebootArgument= ✓ StartLimitIntervalSec=SECONDS ✓ StartLimitBurst=UNSIGNED ✓ StartLimitAction=ACTION ✓ FailureAction= ✓ SuccessAction= ✓ AddRef= ✓ RebootArgument=STRING ✓ ConditionPathExists= ✓ ConditionPathExistsGlob= ✓ ConditionPathIsDirectory= ✓ ConditionPathIsSymbolicLink= ✓ ConditionPathIsMountPoint= ✓ ConditionPathIsReadWrite= ✓ ConditionDirectoryNotEmpty= ✓ ConditionFileNotEmpty= ✓ ConditionFileIsExecutable= ✓ ConditionNeedsUpdate= ✓ ConditionFirstBoot= ✓ ConditionKernelCommandLine= ✓ ConditionKernelVersion= ✓ ConditionArchitecture= ✓ ConditionVirtualization= ✓ ConditionSecurity= ✓ ConditionCapability= ✓ ConditionHost= ✓ ConditionACPower= ✓ ConditionUser= ✓ ConditionGroup= ✓ ConditionControlGroupController= ✓ AssertPathExists= ✓ AssertPathExistsGlob= ✓ AssertPathIsDirectory= ✓ AssertPathIsSymbolicLink= ✓ AssertPathIsMountPoint= ✓ AssertPathIsReadWrite= ✓ AssertDirectoryNotEmpty= ✓ AssertFileNotEmpty= ✓ AssertFileIsExecutable= ✓ AssertNeedsUpdate= ✓ AssertFirstBoot= ✓ AssertKernelCommandLine= ✓ AssertKernelVersion= ✓ AssertArchitecture= ✓ AssertVirtualization= ✓ AssertSecurity= ✓ AssertCapability= ✓ AssertHost= ✓ AssertACPower= ✓ AssertUser= ✓ AssertGroup= ✓ AssertControlGroupController= ✓ CollectMode=
All execution-related settings are available for transient units.
✓ WorkingDirectory= ✓ RootDirectory= ✓ RootImage= ✓ User= ✓ Group= ✓ SupplementaryGroups= ✓ Nice= ✓ OOMScoreAdjust= ✓ IOSchedulingClass= ✓ IOSchedulingPriority= ✓ CPUSchedulingPolicy= ✓ CPUSchedulingPriority= ✓ CPUSchedulingResetOnFork= ✓ CPUAffinity= ✓ UMask= ✓ Environment= ✓ EnvironmentFile= ✓ PassEnvironment= ✓ UnsetEnvironment= ✓ DynamicUser= ✓ RemoveIPC= ✓ StandardInput= ✓ StandardOutput= ✓ StandardError= ✓ StandardInputText= ✓ StandardInputData= ✓ TTYPath= ✓ TTYReset= ✓ TTYVHangup= ✓ TTYVTDisallocate= ✓ SyslogIdentifier= ✓ SyslogFacility= ✓ SyslogLevel= ✓ SyslogLevelPrefix= ✓ LogLevelMax= ✓ LogExtraFields= ✓ LogRateLimitIntervalSec= ✓ LogRateLimitBurst= ✓ SecureBits= ✓ CapabilityBoundingSet= ✓ AmbientCapabilities= ✓ TimerSlackNSec= ✓ NoNewPrivileges= ✓ KeyringMode= ✓ SystemCallFilter= ✓ SystemCallArchitectures= ✓ SystemCallErrorNumber= ✓ MemoryDenyWriteExecute= ✓ RestrictNamespaces= ✓ RestrictRealtime= ✓ RestrictAddressFamilies= ✓ LockPersonality= ✓ LimitCPU= ✓ LimitFSIZE= ✓ LimitDATA= ✓ LimitSTACK= ✓ LimitCORE= ✓ LimitRSS= ✓ LimitNOFILE= ✓ LimitAS= ✓ LimitNPROC= ✓ LimitMEMLOCK= ✓ LimitLOCKS= ✓ LimitSIGPENDING= ✓ LimitMSGQUEUE= ✓ LimitNICE= ✓ LimitRTPRIO= ✓ LimitRTTIME= ✓ ReadWritePaths= ✓ ReadOnlyPaths= ✓ InaccessiblePaths= ✓ BindPaths= ✓ BindReadOnlyPaths= ✓ TemporaryFileSystem= ✓ PrivateTmp= ✓ PrivateDevices= ✓ ProtectKernelTunables= ✓ ProtectKernelModules= ✓ ProtectControlGroups= ✓ PrivateNetwork= ✓ PrivateUsers= ✓ ProtectSystem= ✓ ProtectHome= ✓ MountFlags= ✓ MountAPIVFS= ✓ Personality= ✓ RuntimeDirectoryPreserve= ✓ RuntimeDirectoryMode= ✓ RuntimeDirectory= ✓ StateDirectoryMode= ✓ StateDirectory= ✓ CacheDirectoryMode= ✓ CacheDirectory= ✓ LogsDirectoryMode= ✓ LogsDirectory= ✓ ConfigurationDirectoryMode= ✓ ConfigurationDirectory= ✓ PAMName= ✓ IgnoreSIGPIPE= ✓ UtmpIdentifier= ✓ UtmpMode= ✓ SELinuxContext= ✓ SmackProcessLabel= ✓ AppArmorProfile= ✓ Slice=
All cgroup/resource control settings are available for transient units
✓ CPUAccounting= ✓ CPUWeight= ✓ StartupCPUWeight= ✓ CPUShares= ✓ StartupCPUShares= ✓ CPUQuota= ✓ MemoryAccounting= ✓ MemoryLow= ✓ MemoryHigh= ✓ MemoryMax= ✓ MemorySwapMax= ✓ MemoryLimit= ✓ DeviceAllow= ✓ DevicePolicy= ✓ IOAccounting= ✓ IOWeight= ✓ StartupIOWeight= ✓ IODeviceWeight= ✓ IOReadBandwidthMax= ✓ IOWriteBandwidthMax= ✓ IOReadIOPSMax= ✓ IOWriteIOPSMax= ✓ BlockIOAccounting= ✓ BlockIOWeight= ✓ StartupBlockIOWeight= ✓ BlockIODeviceWeight= ✓ BlockIOReadBandwidth= ✓ BlockIOWriteBandwidth= ✓ TasksAccounting= ✓ TasksMax= ✓ Delegate= ✓ IPAccounting= ✓ IPAddressAllow= ✓ IPAddressDeny=
All process killing settings are available for transient units:
✓ SendSIGKILL= ✓ SendSIGHUP= ✓ KillMode= ✓ KillSignal=
Most service unit settings are available for transient units.
✓ PIDFile= ✓ ExecStartPre= ✓ ExecStart= ✓ ExecStartPost= ✓ ExecReload= ✓ ExecStop= ✓ ExecStopPost= ✓ RestartSec= ✓ TimeoutStartSec= ✓ TimeoutStopSec= ✓ TimeoutSec= ✓ RuntimeMaxSec= ✓ WatchdogSec= ✓ Type= ✓ Restart= ✓ PermissionsStartOnly= ✓ RootDirectoryStartOnly= ✓ RemainAfterExit= ✓ GuessMainPID= ✓ RestartPreventExitStatus= ✓ RestartForceExitStatus= ✓ SuccessExitStatus= ✓ NonBlocking= ✓ BusName= ✓ FileDescriptorStoreMax= ✓ NotifyAccess= Sockets= ✓ USBFunctionDescriptors= ✓ USBFunctionStrings=
All mount unit settings are available to transient units:
✓ What= ✓ Where= ✓ Options= ✓ Type= ✓ TimeoutSec= ✓ DirectoryMode= ✓ SloppyOptions= ✓ LazyUnmount= ✓ ForceUnmount=
All automount unit setting is available to transient units:
✓ Where= ✓ DirectoryMode= ✓ TimeoutIdleSec=
Most timer unit settings are available to transient units.
✓ OnCalendar= ✓ OnActiveSec= ✓ OnBootSec= ✓ OnStartupSec= ✓ OnUnitActiveSec= ✓ OnUnitInactiveSec= ✓ Persistent= ✓ WakeSystem= ✓ RemainAfterElapse= ✓ AccuracySec= ✓ RandomizedDelaySec= Unit=
Slice units are fully supported as transient units, but they have no settings of their own beyond the generic unit and resource control settings.
Scope units are fully supported as transient units (in fact they only exist as such).
✓ TimeoutStopSec=
Most socket unit settings are available to transient units.
✓ ListenStream= ✓ ListenDatagram= ✓ ListenSequentialPacket= ✓ ListenFIFO= ✓ ListenNetlink= ✓ ListenSpecial= ✓ ListenMessageQueue= ✓ ListenUSBFunction= ✓ SocketProtocol= ✓ BindIPv6Only= ✓ Backlog= ✓ BindToDevice= ✓ ExecStartPre= ✓ ExecStartPost= ✓ ExecStopPre= ✓ ExecStopPost= ✓ TimeoutSec= ✓ SocketUser= ✓ SocketGroup= ✓ SocketMode= ✓ DirectoryMode= ✓ Accept= ✓ Writable= ✓ MaxConnections= ✓ MaxConnectionsPerSource= ✓ KeepAlive= ✓ KeepAliveTimeSec= ✓ KeepAliveIntervalSec= ✓ KeepAliveProbes= ✓ DeferAcceptSec= ✓ NoDelay= ✓ Priority= ✓ ReceiveBuffer= ✓ SendBuffer= ✓ IPTOS= ✓ IPTTL= ✓ Mark= ✓ PipeSize= ✓ FreeBind= ✓ Transparent= ✓ Broadcast= ✓ PassCredentials= ✓ PassSecurity= ✓ TCPCongestion= ✓ ReusePort= ✓ MessageQueueMaxMessages= ✓ MessageQueueMessageSize= ✓ RemoveOnStop= ✓ Symlinks= ✓ FileDescriptorName= Service= ✓ TriggerLimitIntervalSec= ✓ TriggerLimitBurst= ✓ SmackLabel= ✓ SmackLabelIPIn= ✓ SmackLabelIPOut= ✓ SELinuxContextFromNet=
Swap units are currently not available at all as transient units:
What= Priority= Options= TimeoutSec=
Most path unit settings are available to transient units.
✓ PathExists= ✓ PathExistsGlob= ✓ PathChanged= ✓ PathModified= ✓ DirectoryNotEmpty= Unit= ✓ MakeDirectory= ✓ DirectoryMode=
The [Install] section is currently not available at all for transient units, and it probably doesn't even make sense.
Alias= WantedBy= RequiredBy= Also= DefaultInstance=