home-environment: make home.activation public

Also improve documentation and add an example.
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Robert Helgesson 2020-01-15 20:57:06 +01:00
parent 7f87329fca
commit f65510b1d1
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@ -235,17 +235,51 @@ in
};
home.activation = mkOption {
internal = true;
type = dagOf types.str;
default = {};
example = literalExample ''
{
myActivationAction = config.lib.dag.entryAfter ["writeBoundary"] '''
$DRY_RUN_CMD ln -s $VERBOSE_ARG \
''${builtins.toPath ./link-me-directly} $HOME
''';
}
'';
description = ''
Activation scripts for the home environment.
The activation scripts blocks to run when activating a Home
Manager generation. Any entry here should be idempotent,
meaning running twice or more times produces the same result
as running it once.
</para><para>
Any script should respect the <varname>DRY_RUN</varname>
variable, if it is set then no actual action should be taken.
If the script block produces any observable side effect, such
as writing or deleting files, then it
<emphasis>must</emphasis> be placed after the special
<literal>writeBoundary</literal> script block. Prior to the
write boundary one can place script blocks that verifies, but
does not modify, the state of the system and exits if an
unexpected state is found. For example, the
<literal>checkLinkTargets</literal> script block checks for
collisions between non-managed files and files defined in
<varname><link linkend="opt-home.file">home.file</link></varname>.
</para><para>
A script block should respect the <varname>DRY_RUN</varname>
variable, if it is set then the actions taken by the script
should be logged to standard out and not actually performed.
The variable <varname>DRY_RUN_CMD</varname> is set to
<code>echo</code> if dry run is enabled. Thus, many cases you
can use the idiom <code>$DRY_RUN_CMD rm -rf /</code>.
<command>echo</command> if dry run is enabled.
</para><para>
A script block should also respect the
<varname>VERBOSE</varname> variable, and if set print
information on standard out that may be useful for debugging
any issue that may arise. The variable
<varname>VERBOSE_ARG</varname> is set to
<option>--verbose</option> if verbose output is enabled.
'';
};