Vaadin observability - OpenTelemetry Extension

Test project for extending the OpenTelemetry with better data

To build the project build an embedded extension with:

./gradlew clean build extendedAgent

Sample usage would then be for instance:

java -javaagent:../extension/build/libs/opentelemetry-javaagent.jar -Dotel.traces.exporter=jaeger -Dotel.exporter.jaeger.endpoint=http://localhost:14250 -Dotel.metrics.exporter=none -jar target/myapp-1.0-SNAPSHOT.jar

The automatic vaadin instrumentation package is disabled so we can handle all the things in a custom way.

Using the project as an extension (instead of embedding): java -javaagent:../opentelemetry-javaagent.jar -Dotel.traces.exporter=jaeger -Dotel.javaagent.extensions=../extension/build/libs/opentelemetry-custom-instrumentation-extension-1.0-all.jar -Dotel.exporter.jaeger.endpoint=http://localhost:14250 -Dotel.metrics.exporter=none -jar target/myapp-1.0-SNAPSHOT.jar

This has the paths
/extension (this project) /my-app (the application)

Also running Jaeger jaeger-all-in-one.exe with default settings.

Development

Linting and Formatting

The project uses [spotless][https://github.com/diffplug/spotless/tree/main/plugin-gradle] for linting and formatting the code.

To lint the code run:

./gradlew spotlessCheck

To format the code run:

./gradlew spotlessApply

Running TomCat with the agent

Tomcat on windows add the file {tomcat}\bin\setenv.bat with the content

set  CATALINA_OPTS=%CATALINA_OPTS% -javaagent:C:\PATH_TO\opentelemetry-javaagent.jar
set  OTEL_METRICS_EXPORTER=none
set  OTEL_TRACES_EXPORTER=jaeger
set  OTEL.EXPORTER.JAEGER.ENDPOINT=http://localhost:14250

for linux/unix the file is {tomcat}/bin/setenv.sh with the content

export CATALINA_OPTS="$CATALINA_OPTS -javaagent:/PATH_TO/opentelemetry-javaagent.jar"
export OTEL_METRICS_EXPORTER=none
export OTEL_TRACES_EXPORTER=jaeger
export OTEL.EXPORTER.JAEGER.ENDPOINT=http://localhost:14250

Maven deployment of extendedAgent

To deploy the extended agent to a maven repository you need to supply credentials as properties mavenUser and mavenPwd, also the repository URL needs to be given as mavenUrl.

These can be given on the command line with the -P flag or in the gradle.properties file.

If targeting a repository behind http then you need to add the allowInsecureProtocol = true flag to the repositories { maven { block.

With the parameters in place just run

gradle build extendedAgent publish