X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.exec.xml;h=207592dda70c7c42198d167b4a480edc4098b726;hp=5721dc15537e9e1901264ccbeccae930d86fe87e;hb=a53692f7b4fb0af771bd510436cc592ef2919f86;hpb=79640424059328268b9fb6c5fa8eb777b27a177e diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml index 5721dc155..207592dda 100644 --- a/man/systemd.exec.xml +++ b/man/systemd.exec.xml @@ -57,7 +57,7 @@ Description Unit configuration files for services, sockets, - mount points and swap devices share a subset of + mount points, and swap devices share a subset of configuration options which define the execution environment of spawned processes. @@ -76,27 +76,6 @@ configuration options are configured in the [Service], [Socket], [Mount], or [Swap] sections, depending on the unit type. - - Processes started by the system systemd instance - are executed in a clean environment in which only the - $PATH and $LANG - variables are set by default. In order to add - additional variables, see the - Environment= and - EnvironmentFile= options below. To - specify variables globally, see - DefaultEnvironment= in - systemd-system.conf5 - or the kernel option - systemd.setenv= in - systemd1. Processes - started by the user systemd instances inherit all - environment variables from the user systemd instance, - and have $HOME, - $USER, - $XDG_RUNTIME_DIR defined, among - others. In addition, $MANAGERPID - contains the PID of the user systemd instance. @@ -867,9 +846,9 @@ 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 + /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 @@ -877,9 +856,17 @@ /tmp or /var/tmp impossible. All temporary data created - by service will be removed after service - is stopped. Defaults to - false. + by service will be removed after + service is stopped. Defaults to + false. Note that it is possible to run + two or more units within the same + private /tmp and + /var/tmp + namespace by using the + JoinsNamespaceOf= + directive, see + systemd.unit5 + for details. @@ -895,8 +882,14 @@ available to the executed process. This is useful to securely turn off network access by the executed - process. Defaults to - false. + process. Defaults to false. Note that + it is possible to run two or more + units within the same private network + namespace by using the + JoinsNamespaceOf= + directive, see + systemd.unit5 + for details. @@ -1005,6 +998,135 @@ + + Environment variables in spawned processes + + Processes started by the system are executed in + a clean environment in which select variables + listed below are set. System processes started by systemd + do not inherit variables from PID 1, but processes + started by user systemd instances inherit all + environment variables from the user systemd instance. + + + + + $PATH + + Colon-separated list + of directiories to use when launching + executables. Systemd uses a fixed + value of + /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin. + + + + + $LANG + + Locale. Can be set in + locale.conf5 + or on the kernel command line (see + systemd1 + and + kernel-command-line7). + + + + + $USER + $LOGNAME + $HOME + $SHELL + + User name (twice), home + directory, and the login shell. + The variables are set for the units that + have User= set, + which includes user + systemd instances. + See + passwd5. + + + + + $XDG_RUNTIME_DIR + + The directory for volatile + state. Set for the user systemd + instance, and also in user sessions. + See + pam_systemd8. + + + + + $XDG_SESSION_ID + $XDG_SEAT + $XDG_VTNR + + The identifier of the + session, the seat name, and + virtual terminal of the session. Set + by + pam_systemd8 + for login sessions. + $XDG_SEAT and + $XDG_VTNR will + only be set when attached to a seat and a + tty. + + + + $MANAGERPID + + The PID of the user + systemd instance, + set for processes spawned by it. + + + + + $LISTEN_FDS + $LISTEN_PID + + Information about file + descriptors passed to a service for + socket activation. See + sd_listen_fds3. + + + + + $TERM + + Terminal type, set + only for units connected to a terminal + (StandardInput=tty, + StandardOutput=tty, + or + StandardError=tty). + See + termcap5. + + + + + Additional variables may be configured by the + following means: for processes spawned in specific + units, use the Environment= and + EnvironmentFile= options above; to + specify variables globally, use + DefaultEnvironment= (see + systemd-system.conf5) + or the kernel option + systemd.setenv= (see + systemd1). Additional + variables may also be set through PAM, + c.f. pam_env8. + + See Also @@ -1017,8 +1139,9 @@ systemd.swap5, systemd.mount5, systemd.kill5, - systemd.cgroup5, - systemd.directives7 + systemd.resource-control5, + systemd.directives7, + exec3