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   systemd.exec    ( 5 )

конфигурация среды выполнения (Execution environment configuration)

Окружение (Environment)

Environment= Sets environment variables for executed processes. Each line is unquoted using the rules described in "Quoting" section in systemd.syntax(7) and becomes a list of variable assignments. If you need to assign a value containing spaces or the equals sign to a variable, put quotes around the whole assignment. Variable expansion is not performed inside the strings and the "$" character has no special meaning. Specifier expansion is performed, see the "Specifiers" section in systemd.unit(5).

This option may be specified more than once, in which case all listed variables will be set. If the same variable is listed twice, the later setting will 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.

The names of the variables can contain ASCII letters, digits, and the underscore character. Variable names cannot be empty or start with a digit. In variable values, most characters are allowed, but non-printable characters are currently rejected.

Example:

Environment="VAR1=word1 word2" VAR2=word3 "VAR3=$word 5 6"

gives three variables "VAR1", "VAR2", "VAR3" with the values "word1 word2", "word3", "$word 5 6".

See environ(7) for details about environment variables.

Note that environment variables are not suitable for passing secrets (such as passwords, key material, ...) to service processes. Environment variables set for a unit are exposed to unprivileged clients via D-Bus IPC, and generally not understood as being data that requires protection. Moreover, environment variables are propagated down the process tree, including across security boundaries (such as setuid/setgid executables), and hence might leak to processes that should not have access to the secret data. Use LoadCredential=, LoadCredentialEncrypted= or SetCredentialEncrypted= (see below) to pass data to unit processes securely.

EnvironmentFile= Similar to Environment= but reads the environment variables from a text file. The text file should contain new-line-separated variable assignments. Empty lines, lines without an "=" separator, or lines starting with ; or # will be ignored, 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 (").

C escapes[7] are supported, but not most control characters[8]. "\t" and "\n" can be used to insert tabs and newlines within EnvironmentFile=.

The argument passed should be an absolute filename or wildcard expression, optionally prefixed with "-", which indicates that if the file does not exist, it will not 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 (more specifically, after all processes from a previous unit state terminated. This means you can generate these files in one unit state, and read it with this option in the next. The files are read from the file system of the service manager, before any file system changes like bind mounts take place).

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.

PassEnvironment= Pass environment variables set for the system service manager to executed processes. Takes a space-separated list of variable names. This option may be specified more than once, in which case all listed variables will be passed. If the empty string is assigned to this option, the list of environment variables to pass is reset, all prior assignments have no effect. Variables specified that are not set for the system manager will not be passed and will be silently ignored. Note that this option is only relevant for the system service manager, as system services by default do not automatically inherit any environment variables set for the service manager itself. However, in case of the user service manager all environment variables are passed to the executed processes anyway, hence this option is without effect for the user service manager.

Variables set for invoked processes due to this setting are subject to being overridden by those configured with Environment= or EnvironmentFile=.

C escapes[7] are supported, but not most control characters[8]. "\t" and "\n" can be used to insert tabs and newlines within EnvironmentFile=.

Example:

PassEnvironment=VAR1 VAR2 VAR3

passes three variables "VAR1", "VAR2", "VAR3" with the values set for those variables in PID1.

See environ(7) for details about environment variables.

UnsetEnvironment= Explicitly unset environment variable assignments that would normally be passed from the service manager to invoked processes of this unit. Takes a space-separated list of variable names or variable assignments. This option may be specified more than once, in which case all listed variables/assignments will be unset. If the empty string is assigned to this option, the list of environment variables/assignments to unset is reset. If a variable assignment is specified (that is: a variable name, followed by "=", followed by its value), then any environment variable matching this precise assignment is removed. If a variable name is specified (that is a variable name without any following "=" or value), then any assignment matching the variable name, regardless of its value is removed. Note that the effect of UnsetEnvironment= is applied as final step when the environment list passed to executed processes is compiled. That means it may undo assignments from any configuration source, including assignments made through Environment= or EnvironmentFile=, inherited from the system manager's global set of environment variables, inherited via PassEnvironment=, set by the service manager itself (such as $NOTIFY_SOCKET and such), or set by a PAM module (in case PAMName= is used).

See "Environment Variables in Spawned Processes" below for a description of how those settings combine to form the inherited environment. See environ(7) for general information about environment variables.