pathextractor

Hyperion - Path Extractor Plugin

This package provides a path extractor plugin that is able to rename fields with java.style.package.Names into their appropriate src/main/java/style/package/Names.java file name. It does this in a dumb manner, simply replacing periods and prefixing a configurable path. If you need a more complex renaming strategy, consider making your own plugin.

Usage

For full details on the supported configuration format, please see the configuration section of this document.

The path extractor plugin is very simple and only has two relevant fields:

field: "log4j_file"
relative-source-path: "src/main/java"
postfix: ".java"

As should already be clear from the naming, in this configuration the plugin will convert an incoming message like

{
  "log4j_file": "com.foo.Bar"
}

into

{
  "log4j_file": "src/main/java/com/foo/Bar.java"
}

Note: If you use Kotlin, this plugin will automatically take care of removing any Kt suffixes added.

Building & Running

To build the library, run gradle pipeline:pathextractor:shadowJar. The result will be located in build/pathextractor-all.jar.

To execute the tests and linting, run gradle pipeline:pathextractor:check.

To run a compiled version of the path extractor plugin, simply launch it using Java:

java -jar build/pathextractor-all.jar [path to config]

Docker

The pathextractor plugin can be easily built and run using Docker.

Running the pre-built Docker image

A pre-built image is available at the Docker hub repository. The plugin image is tagged as sergdelft/hyperion:pipeline-plugins-pathextractor-<version>. Please consult the root README for the latest published version. To run this image with pathextractor_config.yml as its configuration execute:

docker run -it -rm -v ${PWD}/pathextractor_config.yml:/root/config.yml sergdelft/hyperion:pipeline-plugins-pathextractor-0.1.0

Building the Docker image yourself

The included Dockerfile compiles and bundles the plugin. To build it, navigate to the repository root and run the following command:

docker build . -f pipeline/plugins/pathextractor/Dockerfile -t hyperion-pathextractor:latest

Once building completes, the plugin can be ran using the following command, assuming that the configuration file is located at pathextractor_config.yml:

docker run -it -rm -v ${PWD}/pathextractor_config.yml:/root/config.yml hyperion-pathextractor:latest

Configuration

This plugin accepts configuration in a YAML file supplied as a command line argument. The following options are accepted:

# The field that contains a Java package and should be transformed into
# a field name. This may be a nested path using periods.
field: "log4j_file"

# The base relative path that should be prepended to the transformed package
# name. If using Gradle or Maven, this is usually src/main/java or src/main/kotlin.
relative-source-path: "src/main/java"

# The postfix to be added to the log file. Usually `.java` or `.kt`.
postfix: ".java"

# Various settings needed for the plugin to interact with the pipeline,
# such as it's unique ID and the hostname and port of the Hyperion plugin manager.
# 
# Please note that the plugin must also be able to talk to any of its previous
# and next steps in the pipeline. As such, it is recommended that all of the 
# plugins are contained on a single networking setup.
pipeline:
    # The host and port pair that can be used to contact the Hyperion plugin manager.
    # Please note that this machine must be able to talk over TCP to the manager and
    # that the manager must be aware of this plugin/aggregator.
    manager-host: "manager:8000"
  
    # The unique ID of this pipeline step that matches the configuration of the plugin
    # manager. Used to identify which plugins are inputs/outputs of this step. Please
    # note that the plugin will crash at launch if the plugin manager does not recognize
    # this plugin ID.
    plugin-id: "PathExtractor"
  
    # The size of the internal buffer used for storing data that has not yet been processed
    # locally. Increasing this will allow for more messages to be buffered, at the cost of
    # more memory usage. Messages incoming while the buffer is full will be thrown away. If
    # this happens often, consider using the load balancer plugin to shard this plugin across
    # multiple instances. Defaults to 20,000.
    buffer-size: 20000

Input Format

This plugin accepts any type of JSON value as input. If the input is not valid JSON, or if it is not a JSON object, it will be passed to the next stage of the pipeline unaffected. Other than that, any type of JSON object is accepted.

{
    "log4j_file": "com.foo.Bar"
}

Output Format

This plugin will transform the incoming JSON message according to the configuration and output a new JSON object that strictly contains an equal amount of fields as the input. For the example given in the usage section, the output is as follows:

{
    "log4j_file": "src/main/java/com/foo/Bar.java"
}