Fan out isolated batch jobs

mkdir -p jobs results
printf '%s\n' '{"id":"alpha","values":[10,20,30]}' > jobs/alpha.json
printf '%s\n' '{"id":"beta","values":[7,8,9]}' > jobs/beta.json
printf '%s\n' '{"id":"gamma","values":[100,200]}' > jobs/gamma.json

New-Item -ItemType Directory -Force jobs, results | Out-Null
[IO.File]::WriteAllText((Join-Path $PWD 'jobs/alpha.json'), '{"id":"alpha","values":[10,20,30]}')
[IO.File]::WriteAllText((Join-Path $PWD 'jobs/beta.json'), '{"id":"beta","values":[7,8,9]}')
[IO.File]::WriteAllText((Join-Path $PWD 'jobs/gamma.json'), '{"id":"gamma","values":[100,200]}')

pids=()
batch_status=0

for input in jobs/*.json; do
  job="$(basename "$input" .json)"
  msb run --quiet --name "batch-$job" --replace \
    --cpus 1 --memory 256M --max-duration 30s \
    --copy-file "$input:/job/input.json" --workdir /job \
    --no-net --security restricted \
    python:3.13.14-alpine3.23 -- python -c \
      'import json; p=json.load(open("input.json")); print(json.dumps({"id":p["id"],"total":sum(p["values"])}))' \
    > "results/$job.json" &
  pids+=("$!")
done

for pid in "${pids[@]}"; do
  wait "$pid" || batch_status=1
done

test "$batch_status" -eq 0

$workers = Get-ChildItem jobs/*.json | ForEach-Object {
  $inputPath = $_.FullName
  $jobName = $_.BaseName
  $resultPath = Join-Path $PWD "results/$jobName.json"

  Start-Job -ArgumentList $inputPath, $jobName, $resultPath -ScriptBlock {
    param($inputPath, $jobName, $resultPath)

    $result = & msb run --quiet --name "batch-$jobName" --replace `
      --cpus 1 --memory 256M --max-duration 30s `
      --copy-file "${inputPath}:/job/input.json" --workdir /job `
      --no-net --security restricted `
      python:3.13.14-alpine3.23 -- python -c `
        'import json; p=json.load(open("input.json")); print(json.dumps({"id":p["id"],"total":sum(p["values"])}))'

    $status = $LASTEXITCODE
    [IO.File]::WriteAllText($resultPath, ($result -join [Environment]::NewLine))
    if ($status -ne 0) { throw "batch-$jobName failed" }
  }
}

$workers | Wait-Job | Receive-Job
if ($workers.State -contains 'Failed') { throw 'one or more batch jobs failed' }
$workers | Remove-Job

jq . results/*.json

Get-ChildItem results/*.json | ForEach-Object { jq . $_.FullName }

for input in jobs/*.json; do
  msb rm -f "batch-$(basename "$input" .json)"
done

Get-ChildItem jobs/*.json | ForEach-Object {
  msb rm -f "batch-$($_.BaseName)"
}