Jobnik: A Kubernetes native job triggering Service

Jobnik is a tiny web application that allows triggering and monitoring Kubernetes Jobs using standard Rest-API

Features

• Trigger a Kubernetes job via an HTTP POST request with custom environment variables.
• Automatically generates unique job names.
• Monitors job completion.
• Deletes the job 1 minute after it has successfully completed.

Prerequisites

• A Kubernetes cluster with RBAC permissions for job creation and deletion.
• Go application packaged into a Docker container.
• ArgoCD to manage deployments (optional).
• An HTTP client or curl for triggering jobs.

Installation Using Helm

helm install jobnik ./helm/jobnik

By default, Jobnik is deployed with:

• 1 replica
• RBAC enabled
• Memory requests: 128Mi, CPU requests: 64m
• ClusterIP service on port 80 targeting port 8080

---

API Endpoints

1. Trigger a Job (POST /job)

This endpoint creates and runs a new Kubernetes job with optional custom environment variables.

Request

• Method: POST
• URL: /job
• Body: JSON payload specifying the job name, namespace, and optional environment variables.

Request Parameters

Parameter	Type	Required	Description
jobName	string	✅ Yes	Name of the Kubernetes Job to trigger.
namespace	string	✅ Yes	Namespace where the Job should be created.
envVars	object	❌ No	Key-value pairs of environment variables to inject into the Job.

Example Request (cURL)

curl -X POST "http://localhost:8080/job" \
    -H "Accept: application/json" \
    -H "Content-Type: application/json" \
    -d '{
        "jobName": "test-job",
        "namespace": "default",
        "envVars": {
            "AWS_REGION": "us-west-2",
            "S3_BUCKET": "my-data-bucket",
            "DATABASE_URL": "postgres://user:password@db:5432/app",
            "REDIS_HOST": "redis-service",
            "LOG_LEVEL": "debug",
            "SERVICE_NAME": "test-service",
            "MAX_RETRIES": "5",
            "TIMEOUT": "30s",
            "ENABLE_FEATURE_X": "true",
            "INSTANCE_ID": "test-instance-12345"
        }
    }'

Response:

{
  "message": "Job 'test-job-run-1234567890' triggered successfully",
  "job": "test-job-run-1234567890",
  "namespace": "default"
}

2. GET /job

This endpoint fetches the status of a triggered Kubernetes job.

• Method: GET
• URL: /job
• Request params (job, namespace):

Request Parameters

job?job=test-job-run-1735642406-9319&namespace=default

Response:

"job":"test-run-1735745566-9081","status":"succeeded"

---

Triggering a Job via Web Request

You can trigger a job using a simple HTTP request within a Kubernetes cluster. Below are examples in Python, Go, and cURL using an internal Kubernetes service.

Python Example

import requests

# Replace with your internal service name and namespace
url = "http://job-service.default.svc.cluster.local:8080/job"

# Request body containing job details and environment variables
data = {
    "jobName": "test-job",
    "namespace": "default",
    "envVars": {
        "AWS_REGION": "us-west-2",
        "S3_BUCKET": "my-data-bucket",
        "DATABASE_URL": "postgres://user:password@db:5432/app",
        "REDIS_HOST": "redis-service",
        "LOG_LEVEL": "debug",
        "SERVICE_NAME": "test-service",
        "MAX_RETRIES": "5",
        "TIMEOUT": "30s",
        "ENABLE_FEATURE_X": "true",
        "INSTANCE_ID": "test-instance-12345"
    }
}

headers = {"Content-Type": "application/json"}

response = requests.post(url, json=data, headers=headers)

if response.status_code == 200:
    print("Job triggered successfully:", response.json())
else:
    print("Failed to trigger job:", response.text)

---

Go Example

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "net/http"
)

func main() {
    url := "http://job-service.default.svc.cluster.local:8080/job"

    // Request body containing job details and environment variables
    data := map[string]interface{}{
        "jobName":   "test-job",
        "namespace": "default",
        "envVars": map[string]string{
            "AWS_REGION": "us-west-2",
            "S3_BUCKET":  "my-data-bucket",
            "DATABASE_URL": "postgres://user:password@db:5432/app",
            "REDIS_HOST": "redis-service",
            "LOG_LEVEL": "debug",
            "SERVICE_NAME": "test-service",
            "MAX_RETRIES": "5",
            "TIMEOUT": "30s",
            "ENABLE_FEATURE_X": "true",
            "INSTANCE_ID": "test-instance-12345",
        },
    }

    jsonData, err := json.Marshal(data)
    if err != nil {
        fmt.Println("Error marshalling JSON:", err)
        return
    }

    req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
    if err != nil {
        fmt.Println("Error creating request:", err)
        return
    }

    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        fmt.Println("Error sending request:", err)
        return
    }
    defer resp.Body.Close()

    if resp.StatusCode == http.StatusOK {
        fmt.Println("Job triggered successfully!")
    } else {
        fmt.Printf("Failed to trigger job: %d\n", resp.StatusCode)
    }
}

cURL Example

curl -X POST "http://job-service.default.svc.cluster.local:8080/job" \
     -H "Content-Type: application/json" \
     -d '{
        "jobName": "test-job",
        "namespace": "default",
        "envVars": {
            "AWS_REGION": "us-west-2",
            "S3_BUCKET": "my-data-bucket",
            "DATABASE_URL": "postgres://user:password@db:5432/app",
            "REDIS_HOST": "redis-service",
            "LOG_LEVEL": "debug",
            "SERVICE_NAME": "test-service",
            "MAX_RETRIES": "5",
            "TIMEOUT": "30s",
            "ENABLE_FEATURE_X": "true",
            "INSTANCE_ID": "test-instance-12345"
        }
    }'

Response:

{
  "job": "test-job-run-1234567890",
  "status": "running"
}

---

These examples demonstrate how to send a POST request to trigger a job within a Kubernetes cluster using an internal service (job-service.default.svc.cluster.local). Ensure that your service name, namespace, and port match your actual deployment.