- Logstash Reference: other versions:
- Logstash Introduction
- Getting Started with Logstash
- How Logstash Works
- Setting Up and Running Logstash
- Logstash Directory Layout
- Logstash Configuration Files
- logstash.yml
- Secrets keystore for secure settings
- Running Logstash from the Command Line
- Running Logstash as a Service on Debian or RPM
- Running Logstash on Docker
- Configuring Logstash for Docker
- Running Logstash on Kubernetes
- Running Logstash on Windows
- Logging
- Shutting Down Logstash
- Upgrading Logstash
- Creating a Logstash pipeline
- Secure your connection
- Advanced Logstash Configurations
- Logstash-to-Logstash communication
- Managing Logstash
- Using Logstash with Elastic Integrations
- Working with Logstash Modules
- Working with Filebeat Modules
- Working with Winlogbeat Modules
- Queues and data resiliency
- Transforming Data
- Deploying and Scaling Logstash
- Managing GeoIP Databases
- Performance tuning
- Monitoring Logstash with Elastic Agent
- Monitoring Logstash (legacy)
- Monitoring Logstash with APIs
- Working with plugins
- Integration plugins
- Input plugins
- azure_event_hubs
- beats
- cloudwatch
- couchdb_changes
- dead_letter_queue
- elastic_agent
- elastic_serverless_forwarder
- elasticsearch
- exec
- file
- ganglia
- gelf
- generator
- github
- google_cloud_storage
- google_pubsub
- graphite
- heartbeat
- http
- http_poller
- imap
- irc
- java_generator
- java_stdin
- jdbc
- jms
- jmx
- kafka
- kinesis
- logstash
- log4j
- lumberjack
- meetup
- pipe
- puppet_facter
- rabbitmq
- redis
- relp
- rss
- s3
- s3-sns-sqs
- salesforce
- snmp
- snmptrap
- sqlite
- sqs
- stdin
- stomp
- syslog
- tcp
- udp
- unix
- varnishlog
- websocket
- wmi
- xmpp
- Output plugins
- boundary
- circonus
- cloudwatch
- csv
- datadog
- datadog_metrics
- dynatrace
- elastic_app_search
- elastic_workplace_search
- elasticsearch
- exec
- file
- ganglia
- gelf
- google_bigquery
- google_cloud_storage
- google_pubsub
- graphite
- graphtastic
- http
- influxdb
- irc
- java_stdout
- juggernaut
- kafka
- librato
- logstash
- loggly
- lumberjack
- metriccatcher
- mongodb
- nagios
- nagios_nsca
- opentsdb
- pagerduty
- pipe
- rabbitmq
- redis
- redmine
- riak
- riemann
- s3
- sink
- sns
- solr_http
- sqs
- statsd
- stdout
- stomp
- syslog
- tcp
- timber
- udp
- webhdfs
- websocket
- xmpp
- zabbix
- Filter plugins
- age
- aggregate
- alter
- bytes
- cidr
- cipher
- clone
- csv
- date
- de_dot
- dissect
- dns
- drop
- elapsed
- elastic_integration
- elasticsearch
- environment
- extractnumbers
- fingerprint
- geoip
- grok
- http
- i18n
- java_uuid
- jdbc_static
- jdbc_streaming
- json
- json_encode
- kv
- memcached
- metricize
- metrics
- mutate
- prune
- range
- ruby
- sleep
- split
- syslog_pri
- threats_classifier
- throttle
- tld
- translate
- truncate
- urldecode
- useragent
- uuid
- wurfl_device_detection
- xml
- Codec plugins
- Tips and best practices
- Troubleshooting
- Contributing to Logstash
- How to write a Logstash input plugin
- How to write a Logstash codec plugin
- How to write a Logstash filter plugin
- How to write a Logstash output plugin
- Logstash Plugins Community Maintainer Guide
- Document your plugin
- Publish your plugin to RubyGems.org
- List your plugin
- Contributing a patch to a Logstash plugin
- Extending Logstash core
- Contributing a Java Plugin
- Breaking changes
- Release Notes
- Logstash 8.14.3 Release Notes
- Logstash 8.14.2 Release Notes
- Logstash 8.14.1 Release Notes
- Logstash 8.14.0 Release Notes
- Logstash 8.13.4 Release Notes
- Logstash 8.13.3 Release Notes
- Logstash 8.13.2 Release Notes
- Logstash 8.13.1 Release Notes
- Logstash 8.13.0 Release Notes
- Logstash 8.12.2 Release Notes
- Logstash 8.12.1 Release Notes
- Logstash 8.12.0 Release Notes
- Logstash 8.11.4 Release Notes
- Logstash 8.11.3 Release Notes
- Logstash 8.11.2 Release Notes
- Logstash 8.11.1 Release Notes
- Logstash 8.11.0 Release Notes
- Logstash 8.10.4 Release Notes
- Logstash 8.10.3 Release Notes
- Logstash 8.10.2 Release Notes
- Logstash 8.10.1 Release Notes
- Logstash 8.10.0 Release Notes
- Logstash 8.9.2 Release Notes
- Logstash 8.9.1 Release Notes
- Logstash 8.9.0 Release Notes
- Logstash 8.8.2 Release Notes
- Logstash 8.8.1 Release Notes
- Logstash 8.8.0 Release Notes
- Logstash 8.7.1 Release Notes
- Logstash 8.7.0 Release Notes
- Logstash 8.6.2 Release Notes
- Logstash 8.6.1 Release Notes
- Logstash 8.6.0 Release Notes
- Logstash 8.5.3 Release Notes
- Logstash 8.5.2 Release Notes
- Logstash 8.5.1 Release Notes
- Logstash 8.5.0 Release Notes
- Logstash 8.4.2 Release Notes
- Logstash 8.4.1 Release Notes
- Logstash 8.4.0 Release Notes
- Logstash 8.3.3 Release Notes
- Logstash 8.3.2 Release Notes
- Logstash 8.3.1 Release Notes
- Logstash 8.3.0 Release Notes
- Logstash 8.2.3 Release Notes
- Logstash 8.2.2 Release Notes
- Logstash 8.2.1 Release Notes
- Logstash 8.2.0 Release Notes
- Logstash 8.1.3 Release Notes
- Logstash 8.1.2 Release Notes
- Logstash 8.1.1 Release Notes
- Logstash 8.1.0 Release Notes
- Logstash 8.0.1 Release Notes
- Logstash 8.0.0 Release Notes
- Logstash 8.0.0-rc2 Release Notes
- Logstash 8.0.0-rc1 Release Notes
- Logstash 8.0.0-beta1 Release Notes
- Logstash 8.0.0-alpha2 Release Notes
- Logstash 8.0.0-alpha1 Release Notes
Using environment variables
editUsing environment variables
editOverview
edit-
You can set environment variable references in the configuration for Logstash plugins by using
${var}
. - At Logstash startup, each reference is replaced by the value of the environment variable.
- The replacement is case-sensitive.
- References to undefined variables raise a Logstash configuration error.
-
You can give a default value by using the form
${var:default value}
. Logstash uses the default value if the environment variable is undefined. - You can add environment variable references in any plugin option type: string, number, boolean, array, or hash.
- Environment variables for list-type URI parameters can support lists of space-delimited values. Currently, other non-URI based options do not support lists of values. See Cross-plugin concepts and features
- Environment variables are immutable. If you update the environment variable, you’ll have to restart Logstash to pick up the updated value.
Examples
editThese examples show you how to use environment variables to set the values of some commonly used configuration options.
Setting the TCP port
editHere’s an example that uses an environment variable to set the TCP port:
input { tcp { port => "${TCP_PORT}" } }
Now let’s set the value of TCP_PORT
:
export TCP_PORT=12345
At startup, Logstash uses this configuration:
input { tcp { port => 12345 } }
If the TCP_PORT
environment variable is not set, Logstash returns a configuration error.
You can fix this problem by specifying a default value:
input { tcp { port => "${TCP_PORT:54321}" } }
Now, instead of returning a configuration error if the variable is undefined, Logstash uses the default:
input { tcp { port => 54321 } }
If the environment variable is defined, Logstash uses the value specified for the variable instead of the default.
Setting the value of a tag
editHere’s an example that uses an environment variable to set the value of a tag:
filter { mutate { add_tag => [ "tag1", "${ENV_TAG}" ] } }
Let’s set the value of ENV_TAG
:
export ENV_TAG="tag2"
At startup, Logstash uses this configuration:
filter { mutate { add_tag => [ "tag1", "tag2" ] } }
Setting a file path
editHere’s an example that uses an environment variable to set the path to a log file:
filter { mutate { add_field => { "my_path" => "${HOME}/file.log" } } }
Let’s set the value of HOME
:
export HOME="/path"
At startup, Logstash uses the following configuration:
filter { mutate { add_field => { "my_path" => "/path/file.log" } } }