Batch Job Controller

The batch job controller allows executing pods on nodes of a cluster, where the number of concurrent running pods can be
configured. Each pod can report it’s results back to the controller to have them exposed as metrics.

Deployment

The controller expects the following environment variables

Name	Value
NAMESPACE	The current namespace
CONFIG_MAP_NAME	The name of the configmap to read the config from
POD_IP	The IP of the controller Pod. If defined, this IP is used for the callback URL of the job pods.(should be injected via Downward API)

Configuration

The configuration has to be stored in a configmap with the following values

config.yaml

Controller configuration

name: ""                         # name of the controller; will also be used as prefix for the job pods
jobServiceAccount: ""            # service account to be used for the job pods. If empty the default will be used
jobImagePullSecrets:             # pull secrets to be used for the job pods for pulling the image
  - name: secret_name 
jobNodeSelector: { }             # node selector labels to define in which nodes to run the jobs
runOnUnscheduledNodes: true      # if true, jobs are also started on nodes that are unschedulable
cronExpression: "42 3 * * *"     # the cron expression to trigger the job execution
reportDirectory: "/var/www"      # directory to store and serve the reports
reportHistory: 30                # number of execution reports to keep
podPoolSize: 10                  # number of concurrent job pods to run
runOnStartup: true               # if 'true' the jobs are triggered on startup of the controller
startupDelay: 10s                # the delay as duration that is used to start the jobs if runOnStartup is enabled. default is '10s'
callbackServiceName: ""          # name of the controller service
callbackServicePort: 8090        # port of the controller callback api service
custom: { }                       # additional properties that can be used in a custom implementation
latestMetricsLabel: false        # if 'true' each result metric is also created with executionID='latest'
leaderElectionResourceLock: ""   # type of leader election resource lock to be used. ('configmapsleases' (default), 'configmaps', 'endpoints', 'leases', 'endpointsleases')
savePodLog: false                # if enabled, pod logs are saved along other with other job files
metrics:
  prefix: "foo_...."             # prefix for the metrics exposed by the controller
  gauges: # metric gauges that will be exposed by the jobs. The key is uses as suffix for the metrics. 
    test: # suffix of the metric
      help: "help ..."           # help text for the metric
      labels: # list of labels to be used with the metric. node and executionID are automatically added
        - label_a
        - label_b

pod-template.yaml

The template of the pod to be started for each job. When a pod is created it gets enriched by the controller specific
configuration. pkg\job\job.go

Job Pod

The job pod has the following env variables provided by the controller:

Environment

Name	Value
NAMESPACE	The current namespace
NODE_NAME	The name of the node it is running on
EXECUTION_ID	The id of the current job execution
CALLBACK_SERVICE_NAME	The name/host/ip of the callback service to send the report to
CALLBACK_SERVICE_PORT	The port of the callback service to send the report to
CALLBACK_SERVICE_RESULT_URL	The full qualified URL of the result callback service
CALLBACK_SERVICE_FILE_URL	The full qualified URL of the file callback service, to send files to the controller
CALLBACK_SERVICE_EVENT_URL	The full qualified URL of the event callback service, to create k8s event

Callback

The controller exposes by default an endpoint to receive job results. The report is stored locally and metrics of the
reports will be exposed.

URL

The report URL is by default: ${CALLBACK_SERVICE_RESULT_URL}

Body

The body of the report contains the metric suffixes that are also defined in the controller config. Each metric has a
decimal value and a map where the key is the label name and value is the value to be used for the metric label.

{
  "test": [
    {
      "value": 1.0,
      "labels": {
        "label_a": "AAA",
        "label_b": "BBB"
      }
    },
    {
      "value": 2.554,
      "labels": {
        "label_a": "AAA2",
        "label_b": "BBB2"
      }
    }
  ]
}

Example job script: helm\batch-job-controller\bin\run.sh

Upload additional files

Additional files can be uploaded.

Use default ‘Content-Disposition’ header or the name query parameter to define the name of the file. If the name
is not defined an uuid is generated. Each filename is prepended with the node name.

URL

The report URL is by default: ${CALLBACK_SERVICE_FILE_URL}

Create k8s Events from job pod

k8s Event can be created from each job pod by calling the event endpoint.

The ‘reason’ should be short and unique; it must be in UpperCamelCase format (starting with a capital letter).

Simple Message:

{
  "warning": false,
  "reason": "TestReason",
  "message": "test message"
}

Massage with parameters

{
  "warning": true,
  "reason": "TestReason",
  "message": "test message: %s",
  "args": [
    "a1"
  ]
}

URL

The event URL is by default: ${CALLBACK_SERVICE_EVENT_URL}

Examples

test-queries.http