Run Job with script from source control

pipeline.json

{
  "isNew": true,
  "keepWaitingPipelines": false,
  "lastModifiedBy": "anonymous",
  "limitConcurrent": true,
  "stages": [
    {
      "comments": "Replace <ORG>, <REPO>, and <PATH TO FILE> with relevant parameters.",
      "isNew": true,
      "method": "PUT",
      "name": "Fetch Script",
      "payload": {
        "artifactAccount": "github",
        "reference": "https://api.github.com/repos/<ORG>/<REPO>/contents/<PATH TO FILE>",
        "type": "github/file",
        "version": "master"
      },
      "refId": "1",
      "requisiteStageRefIds": [],
      "statusUrlResolution": "getMethod",
      "type": "webhook",
      "url": "http://spin-clouddriver:7002/artifacts/fetch"
    },
    {
      "account": "kubernetes",
      "cloudProvider": "kubernetes",
      "isNew": true,
      "manifests": [
        {
          "apiVersion": "v1",
          "data": {
            "script.sh": "${stage(\"Fetch Script\")[\"context\"][\"webhook\"][\"body\"]"
          },
          "kind": "ConfigMap",
          "metadata": {
            "name": "script-from-github"
          }
        }
      ],
      "moniker": {
        "app": "k8s2"
      },
      "name": "Deploy Script with ConfigMap",
      "refId": "2",
      "requisiteStageRefIds": [
        "1"
      ],
      "skipExpressionEvaluation": false,
      "source": "text",
      "trafficManagement": {
        "enabled": false,
        "options": {
          "enableTraffic": false,
          "namespace": null,
          "services": [],
          "strategy": null
        }
      },
      "type": "deployManifest"
    },
    {
      "account": "kubernetes",
      "alias": "runJob",
      "application": "k8s2",
      "cloudProvider": "kubernetes",
      "credentails": "kubernetes",
      "isNew": true,
      "manifest": {
        "apiVersion": "batch/v1",
        "kind": "Job",
        "metadata": {
          "name": "script-runner"
        },
        "spec": {
          "backoffLimit": 0,
          "template": {
            "spec": {
              "containers": [
                {
                  "command": [
                    "sh",
                    "/opt/scripts/script.sh"
                  ],
                  "image": "alpine:latest",
                  "name": "runner",
                  "volumeMounts": [
                    {
                      "mountPath": "/opt/scripts",
                      "name": "script-from-github"
                    }
                  ]
                }
              ],
              "volumes": [
                {
                  "configMap": {
                    "name": "script-from-github"
                  },
                  "name": "script-from-configmap"
                }
              ]
            }
          }
        }
      },
      "name": "Run Script",
      "refId": "3",
      "requisiteStageRefIds": [
        "2"
      ],
      "source": "text",
      "type": "runJobManifest"
    }
  ],
  "triggers": [],
  "updateTs": "1565616199000"
}