Throw error if EH credential env vars aren't present

pkg/target/eventhub.go

@@ -11,6 +11,7 @@ package target
 import (
 	"context"
 	"fmt"
+	"os"
 	"time"
 
 	eventhub "github.com/Azure/azure-event-hubs-go/v3"
@@ -50,6 +51,12 @@ type EventHubTarget struct {
 // NewEventHubTarget creates a new client for writing messages to Azure EventHub
 func NewEventHubTarget(cfg *EventHubConfig) (*EventHubTarget, error) {
 
+	keyName, keyNamePresent := os.LookupEnv("EVENTHUB_KEY_NAME")
+	keyValue, keyValuePresent := os.LookupEnv("EVENTHUB_KEY_VALUE")
+	if !(keyNamePresent && keyValuePresent) {
+		return nil, errors.Errorf("Error initialising EventHub client: Env vars %s and %s are required for authentication.", keyName, keyValue)
+	}
+
 	hub, err := eventhub.NewHubWithNamespaceNameAndEnvironment(cfg.EventHubNamespace, cfg.EventHubName)
 
 	return &EventHubTarget{