#!/bin/bash
# Spawn a k6 load swarm against a target.
# Usage: ./scripts/loadtest.sh <target-url> [pods] [vus-per-pod] [duration]
# Example: ./scripts/loadtest.sh https://staging.example.com 20 50 5m
#   -> 20 pods x 50 virtual users = 1000 concurrent requests, 5 minutes
set -euo pipefail

TARGET=${1:?usage: loadtest.sh <target-url> [pods] [vus-per-pod] [duration]}
PODS=${2:-20}
VUS=${3:-20}
DURATION=${4:-60s}
NAME="loadtest-$(date +%s)"

kubectl -n loadtest apply -f - <<EOF
apiVersion: batch/v1
kind: Job
metadata:
  name: $NAME
spec:
  parallelism: $PODS
  completions: $PODS
  ttlSecondsAfterFinished: 300
  template:
    spec:
      restartPolicy: Never
      containers:
        - name: k6
          image: grafana/k6:1.4.0
          command: ["k6", "run", "/scripts/test.js"]
          env:
            - {name: TARGET_URL, value: "$TARGET"}
            - {name: VUS, value: "$VUS"}
            - {name: DURATION, value: "$DURATION"}
          resources:
            requests: {cpu: 100m, memory: 128Mi}
            limits: {memory: 256Mi}
          volumeMounts:
            - {name: scripts, mountPath: /scripts}
      volumes:
        - name: scripts
          configMap: {name: k6-script}
EOF

echo "Swarm '$NAME' launched: $PODS pods x $VUS vus for $DURATION against $TARGET"
echo "Watch:  kubectl -n loadtest get pods -w"
echo "Logs:   kubectl -n loadtest logs -f job/$NAME --all-pods=true --tail=5"
echo "Stop:   kubectl -n loadtest delete job $NAME"