- 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 Windows
- Logging
- Shutting Down Logstash
- Installing X-Pack
- Setting Up X-Pack
- Upgrading Logstash
- Configuring Logstash
- Structure of a Config File
- Accessing Event Data and Fields in the Configuration
- Using Environment Variables in the Configuration
- Logstash Configuration Examples
- Multiple Pipelines
- Pipeline-to-Pipeline Communication (Beta)
- Reloading the Config File
- Managing Multiline Events
- Glob Pattern Support
- Converting Ingest Node Pipelines
- Logstash-to-Logstash Communication
- Centralized Pipeline Management
- X-Pack monitoring
- X-Pack security
- X-Pack Settings
- Managing Logstash
- Working with Logstash Modules
- Working with Filebeat Modules
- Data Resiliency
- Transforming Data
- Deploying and Scaling Logstash
- Performance Tuning
- Monitoring Logstash
- Monitoring APIs
- Working with plugins
- Input plugins
- azure_event_hubs
- beats
- cloudwatch
- couchdb_changes
- dead_letter_queue
- elasticsearch
- exec
- file
- ganglia
- gelf
- generator
- github
- google_cloud_storage
- google_pubsub
- graphite
- heartbeat
- http
- http_poller
- imap
- irc
- jdbc
- jms
- jmx
- kafka
- kinesis
- log4j
- lumberjack
- meetup
- pipe
- puppet_facter
- rabbitmq
- redis
- relp
- rss
- s3
- salesforce
- snmp
- snmptrap
- sqlite
- sqs
- stdin
- stomp
- syslog
- tcp
- udp
- unix
- varnishlog
- websocket
- wmi
- xmpp
- Output plugins
- boundary
- circonus
- cloudwatch
- csv
- datadog
- datadog_metrics
- elastic_app_search
- elasticsearch
- exec
- file
- ganglia
- gelf
- google_bigquery
- google_pubsub
- graphite
- graphtastic
- http
- influxdb
- irc
- juggernaut
- kafka
- librato
- loggly
- lumberjack
- metriccatcher
- mongodb
- nagios
- nagios_nsca
- opentsdb
- pagerduty
- pipe
- rabbitmq
- redis
- redmine
- riak
- riemann
- s3
- sns
- solr_http
- sqs
- statsd
- stdout
- stomp
- syslog
- tcp
- timber
- udp
- webhdfs
- websocket
- xmpp
- zabbix
- Filter plugins
- aggregate
- alter
- cidr
- cipher
- clone
- csv
- date
- de_dot
- dissect
- dns
- drop
- elapsed
- elasticsearch
- environment
- extractnumbers
- fingerprint
- geoip
- grok
- http
- i18n
- 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
- xml
- Codec plugins
- Tips and Best Practices
- Troubleshooting Common Problems
- 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
- Documenting your plugin
- Contributing a Patch to a Logstash Plugin
- Logstash Plugins Community Maintainer Guide
- Submitting your plugin to RubyGems.org and the logstash-plugins repository
- Contributing a Java Plugin
- Glossary of Terms
- Breaking Changes
- Release Notes
- Logstash 6.8.23 Release Notes
- Logstash 6.8.22 Release Notes
- Logstash 6.8.21 Release Notes
- Logstash 6.8.20 Release Notes
- Logstash 6.8.19 Release Notes
- Logstash 6.8.18 Release Notes
- Logstash 6.8.17 Release Notes
- Logstash 6.8.16 Release Notes
- Logstash 6.8.15 Release Notes
- Logstash 6.8.14 Release Notes
- Logstash 6.8.13 Release Notes
- Logstash 6.8.12 Release Notes
- Logstash 6.8.11 Release Notes
- Logstash 6.8.10 Release Notes
- Logstash 6.8.9 Release Notes
- Logstash 6.8.8 Release Notes
- Logstash 6.8.7 Release Notes
- Logstash 6.8.6 Release Notes
- Logstash 6.8.5 Release Notes
- Logstash 6.8.4 Release Notes
- Logstash 6.8.3 Release Notes
- Logstash 6.8.2 Release Notes
- Logstash 6.8.1 Release Notes
- Logstash 6.8.0 Release Notes
- Logstash 6.7.2 Release Notes
- Logstash 6.7.1 Release Notes
- Logstash 6.7.0 Release Notes
- Logstash 6.6.2 Release Notes
- Logstash 6.6.1 Release Notes
- Logstash 6.6.0 Release Notes
- Logstash 6.5.4 Release Notes
- Logstash 6.5.3 Release Notes
- Logstash 6.5.2 Release Notes
- Logstash 6.5.1 Release Notes
- Logstash 6.5.0 Release Notes
- Logstash 6.4.3 Release Notes
- Logstash 6.4.2 Release Notes
- Logstash 6.4.1 Release Notes
- Logstash 6.4.0 Release Notes
- Logstash 6.3.2 Release Notes
- Logstash 6.3.1 Release Notes
- Logstash 6.3.0 Release Notes
- Logstash 6.2.4 Release Notes
- Logstash 6.2.3 Release Notes
- Logstash 6.2.2 Release Notes
- Logstash 6.2.1 Release Notes
- Logstash 6.2.0 Release Notes
- Logstash 6.1.3 Release Notes
- Logstash 6.1.2 Release Notes
- Logstash 6.1.1 Release Notes
- Logstash 6.1.0 Release Notes
Using Environment Variables in the Configuration
editUsing Environment Variables in the Configuration
editOverview
edit-
You can set environment variable references in the configuration for Logstash plugins by using
${var}
. - At Logstash startup, each reference will be 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
${var:default value}
. Logstash uses the default value if the environment variable is undefined. - You can add environment variable references in any plugin option type : string, number, boolean, array, or hash.
- Environment variables are immutable. If you update the environment variable, you’ll have to restart Logstash to pick up the updated value.
Examples
editThe following examples show you how to use environment variables to set the values of some commonly used configuration options.
Setting the TCP Port
editHere’s an example that uses an environment variable to set the TCP port:
input { tcp { port => "${TCP_PORT}" } }
Now let’s set the value of TCP_PORT
:
export TCP_PORT=12345
At startup, Logstash uses the following 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 the following 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" } } }