aer_02 (Teragrep syslog bridge function for Microsoft Azure EventHub)

Allows conversion of Azure EventHub events to Syslog messages and sending them to a RELP server. Additional processing of the events can be performed based on the resourceId of the event and an assigned Plugin.

Features

• Receives events from Azure EventHub using Azure Java Function.

• Converts said events to Syslog format.

• Allows sending said Syslog-formatted messages to a RELP server.

• Allows the usage of a certificate from Azure KeyVault for TLS encryption.

• Provides HTTPTrigger function for Prometheus metrics.

• Implements akv_01 library for additional syslog message processing based on resourceId from events received from EventHub.

Documentation

See the official documentation on docs.teragrep.com.

Limitations

Currently only a default Plugin is included in the project. If other type of additional message processing is required, a class implementing Plugin and PluginFactory must be created and added to the configuration file.

How to [compile/use/implement]

Compile using Maven

The project can be compiled using Maven. It is recommended to use Java 11.

$ JAVA_HOME=/usr/lib/jvm/java-11-openjdk mvn clean package

Using the package lifecycle ensures that the necessary JSON manifests to run the Azure Functions are generated.

Usage in Azure

The project must be deployed as a Function in a Function App. The Function App requires or supports the following Environment variables:

Environment variable	Description	Default value	Possible values
EventHubName	Specifies the EventHub name from which to receive the events. Must be provided.	N/A	Any valid EventHub name
EventHubConnectionString	Connection string required to communicate with an EventHub in a namespace. Must be provided.	N/A	Valid EventHub connection string
RELP_TLS_MODE	Specifies which TLS implementation should be used. By default, no encryption is used.	none	none, keyVault
PLUGINS_CONFIG_PATH	Specifies the plugin configuration file path. By default, no configuration is loaded and the DefaultPlugin is used for all resourceIds.	""	valid path, ""
RELP_CONNECTION_TIMEOUT	Specifies the time to wait before timing out connection in milliseconds.	2500	milliseconds (positive integer)
RELP_TRANSACTION_READ_TIMEOUT	Time to wait for destination to acknowledge sent data in milliseconds. Low values may cause duplicates.	1500	milliseconds (positive integer)
RELP_TRANSACTION_WRITE_TIMEOUT	Time to wait for destination to accept data in milliseconds.	1500	milliseconds (positive integer)
RELP_CONNECTION_RETRY_INTERVAL	Time to wait between reconnection attempts in milliseconds.	500	milliseconds (positive integer)
RELP_CONNECTION_PORT	RELP connection destination port	601	valid destination port
RELP_CONNECTION_ADDRESS	RELP connection destination address	localhost	valid destination address
RELP_REBIND_REQUEST_AMOUNT	Rebinds the RELP connection after this amount of records is sent, provided that RELP_REBIND_ENABLED is set to true.	100000	valid amount of records
RELP_REBIND_ENABLED	Rebinds the RELP connection after RELP_REBIND_REQUEST_AMOUNT of records exceeded.	true	true, false
RELP_MAX_IDLE_DURATION	Reconnects to the RELP server before sending messages if the set duration has passed without sending any messages.	PT2M30S	java.time.Duration String representation (PTnHnMnS) If n=0, it can be omitted.
RELP_MAX_IDLE_ENABLED	Enable reconnections if duration described by RELP_MAX_IDLE_DURATION passes without sending any messages.	false	true, false
RELP_CONNECTION_KEEPALIVE	Enable sending alive packets to RELP server	true	true, false
SYSLOG_APPNAME	Default app name to be used in the resulting syslog messages. May be overridden by a Plugin implementation.	aer-02	any string
SYSLOG_HOSTNAME	Default hostname to be used in the resulting syslog messages. May be overridden by a Plugin implementation.	localhost.localdomain	any string

Contributing

You can involve yourself with our project by opening an issue or submitting a pull request.

Contribution requirements:

1. All changes must be accompanied by a new or changed test. If you think testing is not required in your pull request, include a sufficient explanation as why you think so.

2. Security checks must pass

3. Pull requests must align with the principles and values of extreme programming.

4. Pull requests must follow the principles of Object Thinking and Elegant Objects (EO).

Read more in our Contributing Guideline.

Contributor License Agreement

Contributors must sign Teragrep Contributor License Agreement before a pull request is accepted to organization’s repositories.

You need to submit the CLA only once. After submitting the CLA you can contribute to all Teragrep’s repositories.