Tcp output plugin
- Plugin version: v7.0.1
- Released on: 2025-04-29
- Changelog
For other versions, see theVersioned plugin docs.
For questions about the plugin, open a topic in theDiscuss forums. For bugs or feature requests, open an issue inGithub. For the list of Elastic supported plugins, please consult theElastic Support Matrix.
Write events over a TCP socket.
By default this plugin uses thejson
codec. In order to have each event json separated by a newline, use thejson_lines
codec.
Can either accept connections from clients or connect to a server, depending onmode
.
This plugin supports the following configuration options plus theCommon options described later.
As of version7.0.0
of this plugin, a number of previously deprecated settings related to SSL have been removed. Please see theTCP Output Obsolete Configuration Options for more details.
Setting | Input type | Required |
---|---|---|
host | string | Yes |
mode | string, one of["server", "client"] | No |
port | number | Yes |
reconnect_interval | number | No |
ssl_certificate | a valid filesystem path | No |
ssl_certificate_authorities | array | No |
ssl_cipher_suites | string | No |
ssl_client_authentication | string, one of["none", "optional", "required"] | No |
ssl_enabled | boolean | No |
ssl_key | a valid filesystem path | No |
ssl_key_passphrase | password | No |
ssl_supported_protocols | string | No |
ssl_verification_mode | string, one of["full", "none"] | No |
Also seeCommon options for a list of options supported by all output plugins.
- This is a required setting.
- Value type isstring
- There is no default value for this setting.
When mode isserver
, the address to listen on. When mode isclient
, the address to connect to.
- Value can be any of:
server
,client
- Default value is
"client"
Mode to operate in.server
listens for client connections,client
connects to a server.
- This is a required setting.
- Value type isnumber
- There is no default value for this setting.
When mode isserver
, the port to listen on. When mode isclient
, the port to connect to.
- Value type isnumber
- Default value is
10
When connect failed,retry interval in sec.
- Value type ispath
- There is no default value for this setting.
Path to certificate in PEM format. This certificate will be presented to the other part of the TLS connection.
- Value type isarray
- Default value is
[]
Validate client certificate or certificate chain against these authorities. You can define multiple files. All the certificates will be read and added to the trust store. The system CA path is automatically included.
- Value type is a list ofstring
- There is no default value for this setting
The list of cipher suites to use, listed by priorities. Supported cipher suites vary depending on the Java and protocol versions.
- Value can be any of:
none
,optional
,required
- Default value is
none
Controls the server’s behavior in regard to requesting a certificate from client connections:none
disables the client authentication.required
forces a client to present a certificate, whileoptional
requests a client certificate but the client is not required to present one.
When mutual TLS is enabled (optional
orrequired
), the certificate presented by the client must be signed by trustedssl_certificate_authorities
(CAs). Please note that the server does not validate the client certificate CN (Common Name) or SAN (Subject Alternative Name).
This setting can be used only ifmode
isserver
andssl_certificate_authorities
is set.
- Value type isboolean
- Default value is
false
Enable SSL (must be set for otherssl_
options to take effect).
- Value type ispath
- There is no default value for this setting.
SSL key path
- Value type ispassword
- Default value is
nil
SSL key passphrase
- Value type isstring
- Allowed values are:
'TLSv1.1'
,'TLSv1.2'
,'TLSv1.3'
- Default depends on the JDK being used. With up-to-date Logstash, the default is
['TLSv1.2', 'TLSv1.3']
.'TLSv1.1'
is not considered secure and is only provided for legacy applications.
List of allowed SSL/TLS versions to use when establishing a secure connection.
If you configure the plugin to use'TLSv1.1'
on any recent JVM, such as the one packaged with Logstash, the protocol is disabled by default and needs to be enabled manually by changingjdk.tls.disabledAlgorithms
in the$JDK_HOME/conf/security/java.security configuration file. That is,TLSv1.1
needs to be removed from the list.
- Value can be any of:
full
,none
- Default value is
full
Defines how to verify the certificates presented by another part in the TLS connection:
full
validates that the server certificate has an issue date that’s within the not_before and not_after dates; chains to a trusted Certificate Authority (CA), and has a hostname or IP address that matches the names within the certificate.
none
performs no certificate validation.
This setting can be used only ifmode
isclient
.
As of version6.0.0
of this plugin, some configuration options have been replaced. The plugin will fail to start if it contains any of these obsolete options.
Setting | Replaced by |
---|---|
ssl_cacert | ssl_certificate_authorities |
ssl_cert | ssl_certificate |
ssl_enable | ssl_enabled |
ssl_verify | ssl_client_authentication inserver mode andssl_verification_mode inclient mode |
These configuration options are supported by all output plugins:
- Value type iscodec
- Default value is
"json"
The codec used for output data. Output codecs are a convenient method for encoding your data before it leaves the output without needing a separate filter in your Logstash pipeline.
- Value type isboolean
- 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.
- Value type isstring
- There is no default value for this setting.
Add a uniqueID
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 tcp outputs. Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.
output { tcp { id => "my_plugin_id" }}
Variable substitution in theid
field only supports environment variables and does not support the use of values from the secret store.