Support configuration using system properties

[pvid]

It is more convenient to use system properties for configuration.

OpenTelemetry for example allows to use both properties and env variables for configuration, with properties taking precedence, see their implementation.

[netamego]

+1000 :)

I totally agree. It is a very necessary option especially when you profile WebLogic application servers where it is difficult to use environment variables for each java process. It is a headache to use environment variables to configure pyroscope in WebLogic environments. https://stackoverflow.com/questions/23620163/best-way-to-set-environmental-variables-in-weblogic-startup

Thanks a lot @abeaumont . You are doing fast and amazing work.

[korniltsev]

We've implemented configuration with properties in v0.9.0. You can now specify pyroscope configuration:

• from system properties -Dpyroscope.format=jfr
• from pyroscope.properties file/resource pyroscope.format=jfr.

Also pyroscope.properties can be changed to arbitrary location with PYROSCOPE_CONFIGURATION_FILE or pyroscope.configuration property