Prune filter plugin
editPrune filter plugin
edit- Plugin version: v3.0.4
- Released on: 2019-09-12
- Changelog
For other versions, see the Versioned plugin docs.
Installation
editFor plugins not bundled by default, it is easy to install by running bin/logstash-plugin install logstash-filter-prune
. See Working with plugins for more details.
Getting Help
editFor questions about the plugin, open a topic in the Discuss forums. For bugs or feature requests, open an issue in Github. For the list of Elastic supported plugins, please consult the Elastic Support Matrix.
Description
editThe prune filter is for removing fields from events based on whitelists or blacklist of field names or their values (names and values can also be regular expressions).
This can e.g. be useful if you have a json or kv filter that creates a number of fields with names that you don’t necessarily know the names of beforehand, and you only want to keep a subset of them.
Usage help:
To specify a exact field name or value use the regular expression syntax ^some_name_or_value$
.
Example usage: Input data { "msg":"hello world", "msg_short":"hw" }
filter { prune { whitelist_names => [ "msg" ] } } Allows both `"msg"` and `"msg_short"` through.
While:
filter { prune { whitelist_names => ["^msg$"] } } Allows only `"msg"` through.
Logstash stores an event’s tags
as a field which is subject to pruning. Remember to whitelist_names => [ "^tags$" ]
to maintain tags
after pruning or use blacklist_values => [ "^tag_name$" ]
to eliminate a specific tag
.
This filter currently only support operations on top-level fields, i.e. whitelisting and blacklisting of subfields based on name or value does not work.
Prune Filter Configuration Options
editThis plugin supports the following configuration options plus the Common Options described later.
Setting | Input type | Required |
---|---|---|
No |
||
No |
||
No |
||
No |
||
No |
Also see Common Options for a list of options supported by all filter plugins.
blacklist_names
edit- Value type is array
-
Default value is
["%{[^}]+}"]
Exclude fields whose names match specified regexps, by default exclude unresolved %{field}
strings.
filter { prune { blacklist_names => [ "method", "(referrer|status)", "${some}_field" ] } }
blacklist_values
edit- Value type is hash
-
Default value is
{}
Exclude specified fields if their values match one of the supplied regular expressions. In case field values are arrays, each array item is matched against the regular expressions and matching array items will be excluded.
filter { prune { blacklist_values => [ "uripath", "/index.php", "method", "(HEAD|OPTIONS)", "status", "^[^2]" ] } }
interpolate
edit- Value type is boolean
-
Default value is
false
Trigger whether configuration fields and values should be interpolated for
dynamic values (when resolving %{some_field}
).
Probably adds some performance overhead. Defaults to false.
whitelist_names
edit- Value type is array
-
Default value is
[]
Include only fields only if their names match specified regexps, default to empty list which means include everything.
filter { prune { whitelist_names => [ "method", "(referrer|status)", "${some}_field" ] } }
whitelist_values
edit- Value type is hash
-
Default value is
{}
Include specified fields only if their values match one of the supplied regular expressions. In case field values are arrays, each array item is matched against the regular expressions and only matching array items will be included. By default all fields that are not listed in this setting are kept unless pruned by other settings.
filter { prune { whitelist_values => [ "uripath", "/index.php", "method", "(GET|POST)", "status", "^[^2]" ] } }
Common Options
editThe following configuration options are supported by all filter plugins:
Setting | Input type | Required |
---|---|---|
No |
||
No |
||
No |
||
No |
||
No |
||
No |
||
No |
add_field
edit- Value type is hash
-
Default value is
{}
If this filter is successful, add any arbitrary fields to this event.
Field names can be dynamic and include parts of the event using the %{field}
.
Example:
filter { prune { add_field => { "foo_%{somefield}" => "Hello world, from %{host}" } } }
# You can also add multiple fields at once: filter { prune { add_field => { "foo_%{somefield}" => "Hello world, from %{host}" "new_field" => "new_static_value" } } }
If the event has field "somefield" == "hello"
this filter, on success,
would add field foo_hello
if it is present, with the
value above and the %{host}
piece replaced with that value from the
event. The second example would also add a hardcoded field.
add_tag
edit- Value type is array
-
Default value is
[]
If this filter is successful, add arbitrary tags to the event.
Tags can be dynamic and include parts of the event using the %{field}
syntax.
Example:
filter { prune { add_tag => [ "foo_%{somefield}" ] } }
# You can also add multiple tags at once: filter { prune { add_tag => [ "foo_%{somefield}", "taggedy_tag"] } }
If the event has field "somefield" == "hello"
this filter, on success,
would add a tag foo_hello
(and the second example would of course add a taggedy_tag
tag).
enable_metric
edit- Value type is boolean
-
Default value is
true
Disable or enable metric logging for this specific plugin instance. By default we record all the metrics we can, but you can disable metrics collection for a specific plugin.
id
edit- Value type is string
- There is no default value for this setting.
Add a unique ID
to the plugin configuration. If no ID is specified, Logstash will generate one.
It is strongly recommended to set this ID in your configuration. This is particularly useful
when you have two or more plugins of the same type, for example, if you have 2 prune filters.
Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.
filter { prune { id => "ABC" } }
periodic_flush
edit- Value type is boolean
-
Default value is
false
Call the filter flush method at regular interval. Optional.
remove_field
edit- Value type is array
-
Default value is
[]
If this filter is successful, remove arbitrary fields from this event. Fields names can be dynamic and include parts of the event using the %{field} Example:
filter { prune { remove_field => [ "foo_%{somefield}" ] } }
# You can also remove multiple fields at once: filter { prune { remove_field => [ "foo_%{somefield}", "my_extraneous_field" ] } }
If the event has field "somefield" == "hello"
this filter, on success,
would remove the field with name foo_hello
if it is present. The second
example would remove an additional, non-dynamic field.
remove_tag
edit- Value type is array
-
Default value is
[]
If this filter is successful, remove arbitrary tags from the event.
Tags can be dynamic and include parts of the event using the %{field}
syntax.
Example:
filter { prune { remove_tag => [ "foo_%{somefield}" ] } }
# You can also remove multiple tags at once: filter { prune { remove_tag => [ "foo_%{somefield}", "sad_unwanted_tag"] } }
If the event has field "somefield" == "hello"
this filter, on success,
would remove the tag foo_hello
if it is present. The second example
would remove a sad, unwanted tag as well.