Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/inputs/postfix/README.md

@@ -0,0 +1,73 @@
+# Postfix Input Plugin
+
+The postfix plugin reports metrics on the postfix queues.
+
+For each of the active, hold, incoming, maildrop, and deferred queues
+(<http://www.postfix.org/QSHAPE_README.html#queues>), it will report the queue
+length (number of items), size (bytes used by items), and age (age of oldest
+item in seconds).
+
+## Global configuration options <!-- @/docs/includes/plugin_config.md -->
+
+In addition to the plugin-specific configuration settings, plugins support
+additional global and plugin configuration settings. These settings are used to
+modify metrics, tags, and field or create aliases and configure ordering, etc.
+See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
+
+[CONFIGURATION.md]: ../../../docs/CONFIGURATION.md#plugins
+
+## Configuration
+
+```toml @sample.conf
+# Measure postfix queue statistics
+# This plugin ONLY supports non-Windows
+[[inputs.postfix]]
+  ## Postfix queue directory. If not provided, telegraf will try to use
+  ## 'postconf -h queue_directory' to determine it.
+  # queue_directory = "/var/spool/postfix"
+```
+
+### Permissions
+
+Telegraf will need read access to the files in the queue directory.  You may
+need to alter the permissions of these directories to provide access to the
+telegraf user.
+
+This can be setup either using standard unix permissions or with Posix ACLs,
+you will only need to use one method:
+
+Unix permissions:
+
+```sh
+sudo chgrp -R telegraf /var/spool/postfix/{active,hold,incoming,deferred}
+sudo chmod -R g+rXs /var/spool/postfix/{active,hold,incoming,deferred}
+sudo usermod -a -G postdrop telegraf
+sudo chmod g+r /var/spool/postfix/maildrop
+```
+
+Posix ACL:
+
+```sh
+sudo setfacl -Rm g:telegraf:rX /var/spool/postfix/
+sudo setfacl -dm g:telegraf:rX /var/spool/postfix/
+```
+
+## Metrics
+
+- postfix_queue
+  - tags:
+    - queue
+  - fields:
+    - length (integer)
+    - size (integer, bytes)
+    - age (integer, seconds)
+
+## Example Output
+
+```text
+postfix_queue,queue=active length=3,size=12345,age=9
+postfix_queue,queue=hold length=0,size=0,age=0
+postfix_queue,queue=maildrop length=1,size=2000,age=2
+postfix_queue,queue=incoming length=1,size=1020,age=0
+postfix_queue,queue=deferred length=400,size=76543210,age=3600
+```