f399fe3e84
This patch implements two new hooks: alias-resolve and alias-exists. They are called during the aliases resolution process, to allow for more complex integration with other systems, such as storing the aliases in a database. See the included documentation for more details.
2.6 KiB
Hooks
chasquid supports some functionality via hooks, which are binaries that get executed at specific points in time during delivery.
They are optional, and will be skipped if they don't exist.
Post-DATA hook
After completion of DATA, but before accepting the mail for queueing, chasquid
will run the command at $config_dir/hooks/post-data.
The contents of the mail will be written to the command's stdin, and the environment is detailed below.
If the exit status is 0, chasquid will move forward processing the command, and its stdout should contain headers which will be added to contents of the email (at the top).
Otherwise, chasquid will respond with an error, and the last line of stdout will be passed back to the client as the error message. If the exit status is 20 the error code will be permanent, otherwise it will be temporary.
This hook can be used to block based on contents, for example to check for
spam or virus. See etc/hooks/post-data for an example.
Environment
This hook will run as the chasquid user, so be careful about permissions and privileges.
The environment will contain the following variables:
- USER
- SHELL
- PATH
- PWD
- REMOTE_ADDR
- MAIL_FROM
- RCPT_TO (space separated)
- AUTH_AS (empty if not completed AUTH)
- ON_TLS (0 if not, 1 if yes)
- FROM_LOCAL_DOMAIN (0 if not, 1 if yes)
- SPF_PASS (0 if not, 1 if yes)
There is a 1 minute timeout for hook execution. It will be run at the config directory.
Alias resolve hook
When an alias needs to be resolved, chasquid will run the command at
$config_dir/hooks/alias-resolve (if the file exists).
The address to resolve will be passed as the single argument.
The output of the command will be parsed as if it was the right-hand side of the aliases configuration file (see Aliases for more details). Results are appended to the results of the file-based alias resolution.
If there is no alias for the address, the hook should just exit successfuly without emitting any output.
There is a 5 second timeout for hook execution. If the hook exits with an error, including timeout, delivery will fail.
Alias exists hook
When chasquid needs to check whether an alias exists or not, it will run the
command at $config_dir/hooks/alias-exists (if the file exists).
The address to check will be passed as the single argument.
If the commands exits successfuly (exit code 0), then the alias exists; any other exit code signals that the alias does not exist.
There is a 5 second timeout for hook execution. If the hook times out, the alias will be assumed not to exist.