Azure Queue Storage EventSource fails to base64 decode messages containing HTML tags

[Stolz]

Describe the bug

When using Azure Queue Storage EventSource, if the queue contains a base64 encoded JSON message with HTML tags, the EventSource pod fails to base64 decode it.

Steps to reproduce the issue

1. Send to the queue a base64 encoded JSON message that contains some HTML tags

    MESSAGE="`echo '{"html":"<p>test</p>"}' | base64`"
    az storage message put --account-name "$STORAGE_ACCOUNT_NAME" --account-key "$STORAGE_ACCOUNT_KEY" --queue-name example --content="$MESSAGE"
   

2. Verify the queue message can indeed be base64 decoded

    az storage message peek --account-name "$STORAGE_ACCOUNT_NAME" --account-key "$STORAGE_ACCOUNT_KEY" --queue-name example -o tsv --query '[].{Message:content}' | base64 --decode
    {"html":"<p>test</p>"}
   

3. Create a Secret with the connection string for the Storage Account that contains the queue

    kubectl create secret generic queue-access --from-literal='connectionString=...'
   

4. Create an EventSource that listens on the Storage Account queue

apiVersion: argoproj.io/v1alpha1
kind: EventSource
metadata:
  name: example
spec:
  azureQueueStorage:
    example:
      connectionString:
        key: connectionstring
        name: queue-access
      decodeMessage: true
      jsonBody: true # Irrelevant since parsing body step is never reached

Expected behavior

The EventSource should be able to decode the base64 message and publish it to the EventBus.

Actual behavior

The EventSource pod shows this error in the logs:

{"level":"error","ts":1727263035.0298033,"logger":"argo-events.eventsource","caller":"azurequeuestorage/start.go:142","msg":"failed to base64 decode message...","eventSourceName":"example","eventSourceType":"azureQueueStorage","eventName":"example","error":"illegal base64 data at input byte 27","stacktrace":"github.com/argoproj/argo-events/eventsources/sources/azurequeuestorage.(*EventListener).processMessage\n\t/home/runner/work/argo-events/argo-events/eventsources/sources/azurequeuestorage/start.go:142\ngithub.com/argoproj/argo-events/eventsources/sources/azurequeuestorage.(*EventListener).StartListening\n\t/home/runner/work/argo-events/argo-events/eventsources/sources/azurequeuestorage/start.go:116\ngithub.com/argoproj/argo-events/eventsources.(*EventSourceAdaptor).run.func3.1\n\t/home/runner/work/argo-events/argo-events/eventsources/eventing.go:536\ngithub.com/argoproj/argo-events/common.DoWithRetry.func1\n\t/home/runner/work/argo-events/argo-events/common/retry.go:106\nk8s.io/apimachinery/pkg/util/wait.runConditionWithCrashProtection\n\t/home/runner/go/pkg/mod/k8s.io/[email protected]/pkg/util/wait/wait.go:145\nk8s.io/apimachinery/pkg/util/wait.ExponentialBackoff\n\t/home/runner/go/pkg/mod/k8s.io/[email protected]/pkg/util/wait/backoff.go:461\ngithub.com/argoproj/argo-events/common.DoWithRetry\n\t/home/runner/work/argo-events/argo-events/common/retry.go:105\ngithub.com/argoproj/argo-events/eventsources.(*EventSourceAdaptor).run.func3\n\t/home/runner/work/argo-events/argo-events/eventsources/eventing.go:535"}

Environment:

• Kubernetes Client version: 1.31.0
• Kubernetes Server version: 1.30.3
• Argo Events version: 1.9.2 (installed via Helm chart version 2.4.8)

Additional context

If the closing HTML tag is removed from the queue message everything works as expected. i.e:

MESSAGE="`echo '{"html":"<p>test<p>"}' | base64`"
az storage message put --account-name "$STORAGE_ACCOUNT_NAME" --account-key "$STORAGE_ACCOUNT_KEY" --queue-name example --content="$MESSAGE"

{"level":"info","ts":1727263167.2123094,"logger":"argo-events.eventsource","caller":"eventsources/eventing.go:591","msg":"Succeeded to publish an event","eventSourceName":"example","eventName":"example","eventSourceType":"azureQueueStorage","eventID":"31643435616434352d646433382d343862302d383061652d636630323563353838383434"}

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