Add DeadLetterPublisher for publishing poisoned messages to a DLQ topic

[mauriceyap]

A new self-contained pulsarutils.DeadLetterPublisher which wraps a Pulsar producer, publishes a payload plus DeadLetterMetadata (original topic, subscription, attempt count, last error, message IDs) as message properties. Also adds MessageIdsToStrings, a small helper for rendering []pulsar.MessageID as strings for serialization.

(Not wired into anything yet, so
this PR is inert with respect to running behaviour — pure new capability, reviewable purely on its own correctness - producer options, timeout handling, error wrapping).

[greptile-apps]

Greptile Summary

Adds a reusable Pulsar dead-letter publishing capability.

• Introduces DeadLetterPublisher with configurable compression and send timeout.
• Encodes original-message context as Pulsar message properties.
• Adds a helper for rendering Pulsar message IDs as strings.
• Documents the shared pulsarutils package and its publishers.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains within the scope of the available previous review threads.

Important Files Changed

Filename	Overview
internal/common/pulsarutils/dlq_publisher.go	Adds the dead-letter metadata model and a self-contained asynchronous Pulsar publisher with timeout and close handling.
internal/common/pulsarutils/dlq.go	Adds a helper that converts Pulsar message IDs to their string representations.
internal/common/pulsarutils/doc.go	Adds package documentation covering Pulsar construction and publishing helpers.

Sequence Diagram

sequenceDiagram
    participant Caller
    participant DLP as DeadLetterPublisher
    participant Producer as Pulsar Producer
    participant DLQ as Dead-letter Topic
    Caller->>DLP: Publish(ctx, payload, metadata)
    DLP->>DLP: Create timeout context
    DLP->>DLP: Convert metadata to properties
    DLP->>Producer: SendAsync(payload, properties)
    Producer->>DLQ: Publish message
    Producer-->>DLP: Completion callback
    DLP-->>Caller: Success or wrapped error

Loading

_{Reviews (5): Last reviewed commit: "Add DeadLetterPublisher for publishing p..." | Re-trigger Greptile}

[datadog-armadaproject]

⚠️ Warnings

🚦 1 Pipeline job failed

CI | All jobs succeeded     

Useful? React with 👍 / 👎

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: c6a844a | Docs | Datadog PR Page | Give us feedback!}

[mergify]

Tick the box to add this pull request to the merge queue (same as @mergifyio queue).

• Queue this pull request