Documented using the Prism runner (#3656)

There is now a portable runner for local beam jobs written natively in Go. This means we don't have to set any python stuff up any more! It also enforces that functions are properly serializable and registered, which makes it better than the old direct runner.

Author: mhutchinson

experimental/batchmap/README.md

@@ -54,40 +54,15 @@ are identified.
 ### Setup
 
 The map uses Apache Beam to assemble and run a pipeline of tasks to construct the map.
-The following instructions show how to run this code locally using the Python portable runner.
-Comprehensive documentation for setting up a Python environment is beyond the scope of this demo, but instructions can be found at [Beam Python Tips](https://cwiki.apache.org/confluence/display/BEAM/Python+Tips).
-Steps that worked for me using python 3.10.12 on a Debian machine are:
-
-```shell
-python3 --version # Confirm 3.10.12
-sudo apt install python3-venv
-
-# Create a virtual python env for configuring the runner and deps
-python3 -m venv ~/Virtualenvs/beampy31012
-source ~/Virtualenvs/beampy31012/bin/activate
-python3 -m pip install --upgrade pip
-pip install wheel
-pip install apache-beam
-
-# Now run the portable runner, and leave it listening for work on 8099
-python -m apache_beam.runners.portability.local_job_service_main --port=8099
-```
-
-Alternate steps that may work from checking out the source repo:
-
-1. Check out `github.com/apache/beam` (tested at branch `release-2.24.0`)
-2. `cd sdks/python` within that repository
-3. `python -m apache_beam.runners.portability.local_job_service_main --port=8099`
-
+Fortunately there is now a Go local portable runner, so you don't need to set up Python any more!
 
 ### Building the map
 
 These instructions are for Linux/MacOS but can likely be adapted for Windows.
-Ensure that you have a python portable runner listening on port 8099, as documented above.
 
 In another terminal:
 1. Check out this repository and `cd` to the folder containing this README
-2. `go run ./cmd/build/mapdemo.go --output=/tmp/mapv1 --runner=universal --endpoint=localhost:8099 --environment_type=LOOPBACK`
+2. `go run ./cmd/build/mapdemo.go --output=/tmp/mapv1 --runner=PrismRunner`
 
 The pipeline should run and generate files under the ouput directory, each of which contains a tile from the map.
 Note that a new file will be constructed for each tile output, which can get very large

experimental/batchmap/cmd/build/mapdemo.go

@@ -89,6 +89,7 @@ func main() {
 	if err := beamx.Run(context.Background(), p); err != nil {
 		klog.Fatalf("Failed to execute job: %v", err)
 	}
+	klog.Infof("Pipeline completed successfully! Output data is at %s", output)
 }
 
 // mapEntryFn is a Beam ParDo function that generates a key/value from an int64 input.