X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.exec.xml;h=69ee4fc5e88c71b4168711d4350d6534f5a296b7;hp=68495dcaf770a61ed346ebf2f4e57ddca61a5e00;hb=d91c34f21ff7445dcee3efe2368aebe2d6c266db;hpb=f3e219a238c716ffa06fab7b0618197c090dfd5a diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml index 68495dcaf..69ee4fc5e 100644 --- a/man/systemd.exec.xml +++ b/man/systemd.exec.xml @@ -9,16 +9,16 @@ Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU General Public License + You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . --> @@ -44,50 +44,57 @@ systemd.exec - systemd execution environment configuration + Execution environment configuration - systemd.service, - systemd.socket, - systemd.mount + service.service, + socket.socket, + mount.mount, + swap.swap Description - Unit configuration files for services, sockets - and mount points share a subset of configuration - options which define the execution environment of - spawned processes. + Unit configuration files for services, sockets, + mount points and swap devices share a subset of + configuration options which define the execution + environment of spawned processes. This man page lists the configuration options - shared by these three unit types. See + shared by these four unit types. See systemd.unit5 for the common options of all unit configuration files, and - systemd.service5, systemd.socket5 + systemd.service5, + systemd.socket5, + systemd.swap5 and systemd.mount5 for more information on the specific unit configuration files. The execution specific configuration options are configured in the [Service], - [Socket] resp. [Mount] section, depending on the unit + [Socket], [Mount], or [Swap] sections, depending on the unit type. Options - + WorkingDirectory= Takes an absolute directory path. Sets the working - directory for executed - processes. + directory for executed processes. If + not set defaults to the root directory + when systemd is running as a system + instance and the respective user's + home directory if run as + user. @@ -110,10 +117,10 @@ Group= Sets the Unix user - resp. group the processes are executed - as. Takes a single user resp. group + or group that the processes are executed + as, respectively. Takes a single user or group name or ID as argument. If no group is - set the default group of the user is + set, the default group of the user is chosen. @@ -122,14 +129,19 @@ Sets the supplementary Unix groups the processes are executed - as. This takes a space seperated list + as. This takes a space separated list of group names or IDs. This option may be specified more than once in which case all listed groups are set as - supplementary groups. This option does - not override but extend the list of - supplementary groups configured in the - system group database for the + supplementary groups. When the empty + string is assigned the list of + supplementary groups is reset, and all + assignments prior to this one will + have no effect. In any way, this + option does not override, but extends + the list of supplementary groups + configured in the system group + database for the user. @@ -146,13 +158,13 @@ - OOMAdjust= + OOMScoreAdjust= Sets the adjustment level for the Out-Of-Memory killer for executed processes. Takes an integer - between -17 (to disable OOM killing - for this process) and 15 (to make + between -1000 (to disable OOM killing + for this process) and 1000 (to make killing of this process under memory pressure very likely). See proc.txt @@ -207,13 +219,15 @@ Sets the CPU scheduling priority for executed - processes. Takes an integer between 1 - (lowest priority) and 99 (highest - priority). The available priority + processes. The available priority range depends on the selected CPU - scheduling policy (see above). See - sched_setscheduler2 - for details. + scheduling policy (see above). For + real-time scheduling policies an + integer between 1 (lowest priority) + and 99 (highest priority) can be used. + See sched_setscheduler2 + for details. + @@ -234,8 +248,14 @@ Controls the CPU affinity of the executed - processes. Takes a space-seperated - list of CPU indexes. See + processes. Takes a space-separated + list of CPU indexes. This option may + be specified more than once in which + case the specificed CPU affinity masks + are merged. If the empty string is + assigned the mask is reset, all + assignments prior to this will have no + effect. See sched_setaffinity2 for details. @@ -248,7 +268,7 @@ octal notation. See umask2 for details. Defaults to - 0002. + 0022. @@ -256,15 +276,34 @@ Sets environment variables for executed - processes. Takes a space-seperated + processes. Takes a space-separated list of variable assignments. This option may be specified more than once in which case all listed variables will be set. If the same variable is set twice the later setting will - override the earlier setting. See + override the earlier setting. If the + empty string is assigned to this + option the list of environment + variables is reset, all prior + assignments have no effect. + Variable expansion is not performed + inside the strings, and $ has no special + meaning. + If you need to assign a value containing spaces + to a variable, use double quotes (") + for the assignment. + + Example: + Environment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6" + gives three variables VAR1, + VAR2, VAR3. + + + + See environ7 - for details. + for details about environment variables. EnvironmentFile= @@ -272,11 +311,41 @@ Environment= but reads the environment variables from a text file. The text file should - contain new-line seperated variable + contain new-line separated variable assignments. Empty lines and lines starting with ; or # will be ignored, - which may be used for - commenting. + which may be used for commenting. A line + ending with a backslash will be concatenated + with the following one, allowing multiline variable + definitions. The parser strips leading + and trailing whitespace from the values + of assignments, unless you use + double quotes ("). + + The argument passed should be an + absolute file name or wildcard + expression, optionally prefixed with + "-", which indicates that if the file + does not exist it won't be read and no + error or warning message is logged. + This option may be specified more than + once in which case all specified files + are read. If the empty string is + assigned to this option the list of + file to read is reset, all prior + assignments have no effect. + + The files listed with this + directive will be read shortly before + the process is executed. Settings from + these files override settings made + with + Environment=. If + the same variable is set twice from + these files the files will be read in + the order they are specified and the + later setting will override the + earlier setting. @@ -301,10 +370,11 @@ below) and the executed process becomes the controlling process of the terminal. If the terminal is already - being controlled by another process it - is waited until that process releases - the - terminal. + being controlled by another process the + executed process waits until the current + controlling process releases the + terminal. + is similar to , but the executed process is forcefully and immediately made the controlling @@ -341,7 +411,11 @@ , , , - or + , + , + , + , + or . If set to the file descriptor of standard input is @@ -362,30 +436,53 @@ terminal. connects standard output to the syslog3 - system logger. + system syslog + service. connects it with the kernel log buffer which is accessible via - dmesg1. - connects standard output to a socket - from socket activation, semantics are + dmesg1. + connects it with the journal which is + accessible via + journalctl1 + (Note that everything that is written + to syslog or kmsg is implicitly stored + in the journal as well, those options + are hence supersets of this + one). , + and + work + similarly but copy the output to the + system console as + well. connects + standard output to a socket from + socket activation, semantics are similar to the respective option of StandardInput=. - This setting defaults to - . + This setting defaults to the value set + with + + in + systemd-system.conf5, + which defaults to + . - StandardOutput= + StandardError= Controls where file descriptor 2 (STDERR) of the executed processes is connected to. The available options are identical to those of - StandardError=, - whith one exception: if set to + StandardOutput=, + with one exception: if set to the file descriptor used for standard output is duplicated for standard error. This - setting defaults to + setting defaults to the value set with + + in + systemd-system.conf5, + which defaults to . @@ -397,7 +494,37 @@ /dev/console. - SyslogIdentifer= + TTYReset= + Reset the terminal + device specified with + TTYPath= before and + after execution. Defaults to + no. + + + TTYVHangup= + Disconnect all clients + which have opened the terminal device + specified with + TTYPath= + before and after execution. Defaults + to + no. + + + TTYVTDisallocate= + If the terminal + device specified with + TTYPath= is a + virtual console terminal try to + deallocate the TTY before and after + execution. This ensures that the + screen and scrollback buffer is + cleared. Defaults to + no. + + + SyslogIdentifier= Sets the process name to prefix log lines sent to syslog or the kernel log buffer with. If not set @@ -470,7 +597,7 @@ prefixes may be disabled with SyslogLevelPrefix=, see below. For details see - sd-daemon7. + sd-daemon3. Defaults to . @@ -482,8 +609,9 @@ argument. If true and StandardOutput= or StandardError= are - set to or - log lines + set to , + or + , log lines written by the executed process that are prefixed with a log level will be passed on to syslog with this log @@ -492,7 +620,7 @@ these prefixes is disabled and the logged lines are passed on as-is. For details about this prefixing see - sd-daemon7. + sd-daemon3. Defaults to true. @@ -500,16 +628,17 @@ TimerSlackNSec= Sets the timer slack in nanoseconds for the executed - processes The timer slack controls the - accuracy of wake-ups triggered by + processes. The timer slack controls + the accuracy of wake-ups triggered by timers. See prctl2 for more information. Note that in contrast to most other time span - definitions this value is takes a - nano-seconds integer and does not - understand any other - units. + definitions this parameter takes an + integer value in nano-seconds if no + unit is specified. The usual time + units are understood + too. @@ -533,7 +662,10 @@ various resource limits for executed processes. See setrlimit2 - for details. + for details. Use the string + infinity to + configure no limit on a specific + resource. @@ -561,27 +693,64 @@ conjunction with socket-activated services, and stream sockets (TCP) in particular. It has no effect on other - socket types (e.g. datagram/UDP) and on processes - unrelated to socket-based + socket types (e.g. datagram/UDP) and + on processes unrelated to socket-based activation. If the tcpwrap verification fails daemon start-up will fail and the connection is terminated. See tcpd8 - for details. + for details. Note that this option may + be used to do access control checks + only. Shell commands and commands + described in + hosts_options5 + are not supported. - Capabilities= - Controls the + CapabilityBoundingSet= + + Controls which + capabilities to include in the + capability bounding set for the + executed process. See capabilities7 - set for the executed process. Take a - capability string as described in - cap_from_text3. - Note that this capability set is - usually influenced by the capabilities - attached to the executed - file. + for details. Takes a whitespace + separated list of capability names as + read by + cap_from_name3, + e.g. CAP_SYS_ADMIN + CAP_DAC_OVERRIDE + CAP_SYS_PTRACE. + Capabilities listed will be included + in the bounding set, all others are + removed. If the list of capabilities + is prefixed with ~ + all but the listed capabilities will + be included, the effect of the + assignment inverted. Note that this + option also affects the respective + capabilities in the effective, + permitted and inheritable capability + sets, on top of what + Capabilities= + does. If this option is not used the + capability bounding set is not + modified on process execution, hence + no limits on the capabilities of the + process are enforced. This option may + appear more than once in which case + the bounding sets are merged. If the + empty string is assigned to this + option the bounding set is reset to + the empty capability set, and all + prior settings have no effect. If set + to ~ (without any + further argument) the bounding set is + reset to the full set of available + capabilities, also undoing any + previous settings. @@ -594,22 +763,31 @@ , , , - and/or - . - + and/or + . This + option may appear more than once in + which case the secure bits are + ORed. If the empty string is assigned + to this option the bits are reset to + 0. - CapabilityBoundingSetDrop= - + Capabilities= Controls the - capability bounding set drop set for - the executed process. See capabilities7 - for details. Takes a list of - capability names as read by - cap_from_name3. - + set for the executed process. Take a + capability string describing the + effective, permitted and inherited + capability sets as documented in + cap_from_text3. + Note that these capability sets are + usually influenced by the capabilities + attached to the executed file. Due to + that + CapabilityBoundingSet= + is probably the much more useful + setting. @@ -617,36 +795,268 @@ Controls the control groups the executed processes shall be - made member of. Takes a - space-seperated list of cgroup - identifiers. A cgroup identifier has a - format like + made members of. Takes a + space-separated list of cgroup + identifiers. A cgroup identifier is + formatted like cpu:/foo/bar, - where "cpu" identifies the kernel + where "cpu" indicates the kernel control group controller used, and /foo/bar is the - control group path. The controller name - and ":" may be omitted in which case - the named systemd control group + control group path. The controller + name and ":" may be omitted in which + case the named systemd control group hierarchy is implied. Alternatively, the path and ":" may be omitted, in which case the default control group - path for this unit is implied. This - option may be used to place executed - processes in arbitrary groups in - arbitrary hierachies -- which can be - configured externally with additional execution limits. By default - systemd will place all executed - processes in seperate per-unit control - groups (named after the unit) in the - systemd named hierarchy. Since every - process can be in one group per - hierarchy only overriding the control group - path in the named systemd hierarchy - will disable automatic placement in - the default group. For details about control - groups see cgroups.txt. + path for this unit is implied. + + This option may be used to place + executed processes in arbitrary groups + in arbitrary hierarchies -- which may + then be externally configured with + additional execution limits. By + default systemd will place all + executed processes in separate + per-unit control groups (named after + the unit) in the systemd named + hierarchy. This option is primarily + intended to place executed processes + in specific paths in specific kernel + controller hierarchies. It is not + recommended to manipulate the service + control group path in the systemd + named hierarchy. For details about + control groups see cgroups.txt. + + This option may appear more than + once, in which case the list of + control group assignments is + merged. If the same hierarchy gets two + different paths assigned only the + later setting will take effect. If the + empty string is assigned to this + option the list of control group + assignments is reset, all previous + assignments will have no + effect. + + Note that the list of control + group assignments of a unit is + extended implicitly based on the + settings of + DefaultControllers= + of + systemd-system.conf5, + but a unit's + ControlGroup= + setting for a specific controller + takes precedence. + + + + ControlGroupModify= + Takes a boolean + argument. If true, the control groups + created for this unit will be owned by + the user specified with + User= (and the + appropriate group), and he/she can create + subgroups as well as add processes to + the group. + + + + ControlGroupPersistent= + Takes a boolean + argument. If true, the control groups + created for this unit will be marked + to be persistent, i.e. systemd will + not remove them when stopping the + unit. The default is false, meaning + that the control groups will be + removed when the unit is stopped. For + details about the semantics of this + logic see PaxControlGroups. + + + + ControlGroupAttribute= + + Set a specific control + group attribute for executed + processes, and (if needed) add the + executed processes to a cgroup in the + hierarchy of the controller the + attribute belongs to. Takes two + space-separated arguments: the + attribute name (syntax is + cpu.shares where + cpu refers to a + specific controller and + shares to the + attribute name), and the attribute + value. Example: + ControlGroupAttribute=cpu.shares + 512. If this option is used + for an attribute that belongs to a + kernel controller hierarchy the unit + is not already configured to be added + to (for example via the + ControlGroup= + option) then the unit will be added to + the controller and the default unit + cgroup path is implied. Thus, using + ControlGroupAttribute= + is in most cases sufficient to make + use of control group enforcements, + explicit + ControlGroup= are + only necessary in case the implied + default control group path for a + service is not desirable. For details + about control group attributes see + cgroups.txt. This + option may appear more than once, in + order to set multiple control group + attributes. If this option is used + multiple times for the same cgroup + attribute only the later setting takes + effect. If the empty string is + assigned to this option the list of + attributes is reset, all previous + cgroup attribute settings have no + effect, including those done with + CPUShares=, + MemoryLimit=, + MemorySoftLimit, + DeviceAllow=, + DeviceDeny=, + BlockIOWeight=, + BlockIOReadBandwidth=, + BlockIOWriteBandwidth=. + + + + + CPUShares= + + Assign the specified + overall CPU time shares to the + processes executed. Takes an integer + value. This controls the + cpu.shares control + group attribute, which defaults to + 1024. For details about this control + group attribute see sched-design-CFS.txt. + + + + MemoryLimit= + MemorySoftLimit= + + Limit the overall memory usage + of the executed processes to a certain + size. Takes a memory size in bytes. If + the value is suffixed with K, M, G or + T the specified memory size is parsed + as Kilobytes, Megabytes, Gigabytes, + or Terabytes (to the base + 1024), respectively. This controls the + memory.limit_in_bytes + and + memory.soft_limit_in_bytes + control group attributes. For details + about these control group attributes + see memory.txt. + + + + DeviceAllow= + DeviceDeny= + + Control access to + specific device nodes by the executed processes. Takes two + space separated strings: a device node + path (such as + /dev/null) + followed by a combination of r, w, m + to control reading, writing, or + creating of the specific device node + by the unit, respectively. This controls the + devices.allow + and + devices.deny + control group attributes. For details + about these control group attributes + see devices.txt. + + + + BlockIOWeight= + + Set the default or + per-device overall block IO weight + value for the executed + processes. Takes either a single + weight value (between 10 and 1000) to + set the default block IO weight, or a + space separated pair of a file path + and a weight value to specify the + device specific weight value (Example: + "/dev/sda 500"). The file path may be + specified as path to a block device + node or as any other file in which + case the backing block device of the + file system of the file is + determined. This controls the + blkio.weight and + blkio.weight_device + control group attributes, which + default to 1000. Use this option + multiple times to set weights for + multiple devices. For details about + these control group attributes see + blkio-controller.txt. + + + + BlockIOReadBandwidth= + BlockIOWriteBandwidth= + + Set the per-device + overall block IO bandwidth limit for + the executed processes. Takes a space + separated pair of a file path and a + bandwidth value (in bytes per second) + to specify the device specific + bandwidth. The file path may be + specified as path to a block device + node or as any other file in which + case the backing block device of the + file system of the file is determined. + If the bandwidth is suffixed with K, M, + G, or T the specified bandwidth is + parsed as Kilobytes, Megabytes, + Gigabytes, or Terabytes, respectively (Example: + "/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 + 5M"). This controls the + blkio.read_bps_device + and + blkio.write_bps_device + control group attributes. Use this + option multiple times to set bandwidth + limits for multiple devices. For + details about these control group + attributes see blkio-controller.txt. @@ -660,7 +1070,7 @@ to limit access a process might have to the main file-system hierarchy. Each setting takes a - space-seperated list of absolute + space-separated list of absolute directory paths. Directories listed in ReadWriteDirectories= are accessible from within the @@ -672,36 +1082,61 @@ usual file access controls would permit this. Directories listed in InaccessibleDirectories= - will be made inaccesible for processes - inside the namespace. Note that - restricting access with these options - does not extend to submounts of a - directory. You must list submounts - seperately in these setttings to - ensure the same limited access. These - options may be specified more than - once in which case all directories - listed will have limited access from - within the - namespace. + will be made inaccessible for + processes inside the namespace. Note + that restricting access with these + options does not extend to submounts + of a directory. You must list + submounts separately in these settings + to ensure the same limited + access. These options may be specified + more than once in which case all + directories listed will have limited + access from within the namespace. If + the empty string is assigned to this + option the specific list is reset, and + all prior assignments have no + effect. PrivateTmp= Takes a boolean - argument. If true sets up a new - namespace for the executed processes - and mounts a private - /tmp directory - inside it, that is not shared by + argument. If true sets up a new file + system namespace for the executed + processes and mounts private + /tmp and + /var/tmp directories + inside it, that are not shared by processes outside of the namespace. This is useful to secure access to temporary files of the process, but makes sharing between processes via - /tmp - impossible. Defaults to false. + /tmp or + /var/tmp + impossible. All temporary data created + by service will be removed after service + is stopped. Defaults to + false. + + + + PrivateNetwork= + + Takes a boolean + argument. If true sets up a new + network namespace for the executed + processes and configures only the + loopback network device + lo inside it. No + other network devices will be + available to the executed process. + This is useful to securely turn off + network access by the executed + process. Defaults to + false. @@ -712,20 +1147,98 @@ , or , which - control whether namespaces set up with - ReadWriteDirectories=, - ReadOnlyDirectories= - and - InaccessibleDirectories= - receive or propagate new mounts - from/to the main namespace. See - mount1 - for details. Defaults to - , i.e. the new - namespace will both receive new mount - points from the main namespace as well - as propagate new mounts to - it. + control whether the file system + namespace set up for this unit's + processes will receive or propagate + new mounts. See + mount2 + for details. Default to + . + + + + UtmpIdentifier= + + Takes a four + character identifier string for an + utmp/wtmp entry for this service. This + should only be set for services such + as getty + implementations where utmp/wtmp + entries must be created and cleared + before and after execution. If the + configured string is longer than four + characters it is truncated and the + terminal four characters are + used. This setting interprets %I style + string replacements. This setting is + unset by default, i.e. no utmp/wtmp + entries are created or cleaned up for + this service. + + + + IgnoreSIGPIPE= + + Takes a boolean + argument. If true causes SIGPIPE to be + ignored in the executed + process. Defaults to true, since + SIGPIPE generally is useful only in + shell pipelines. + + + + NoNewPrivileges= + + Takes a boolean + argument. If true ensures that the + service process and all its children + can never gain new privileges. This + option is more powerful than the respective + secure bits flags (see above), as it + also prohibits UID changes of any + kind. This is the simplest, most + effective way to ensure that a process + and its children can never elevate + privileges again. + + + + SystemCallFilter= + + Takes a space + separated list of system call + names. If this setting is used all + system calls executed by the unit + process except for the listed ones + will result in immediate process + termination with the SIGSYS signal + (whitelisting). If the first character + of the list is ~ + the effect is inverted: only the + listed system calls will result in + immediate process termination + (blacklisting). If this option is used + NoNewPrivileges=yes + is implied. This feature makes use of + the Secure Computing Mode 2 interfaces + of the kernel ('seccomp filtering') + and is useful for enforcing a minimal + sandboxing environment. Note that the + execve, + rt_sigreturn, + sigreturn, + exit_group, + exit system calls + are implicitly whitelisted and don't + need to be listed explicitly. This + option may be specified more than once + in which case the filter masks are + merged. If the empty string is + assigned the filter is reset, all + prior assignments will have no + effect. @@ -736,10 +1249,14 @@ systemd1, systemctl8, + journalctl8, systemd.unit5, systemd.service5, systemd.socket5, - systemd.mount5 + systemd.swap5, + systemd.mount5, + systemd.kill5, + systemd.directives7