redis

BabelQueue Redis transport (Go)

A Redis-backed babelqueue.Transport for the BabelQueue Go runtime, using the reliable-queue pattern (RPUSH to produce, BLMOVE head → per-queue processing list to reserve, LREM to ack). Built on go-redis.

go get github.com/babelqueue/babelqueue-go/redis

import (
    babelqueue "github.com/babelqueue/babelqueue-go"
    "github.com/babelqueue/babelqueue-go/redis"
)

tr, err := redis.New("redis://localhost:6379/0")
if err != nil { panic(err) }
defer tr.Close()

app := babelqueue.NewApp(tr, babelqueue.WithDefaultQueue("orders"))
app.Handle("urn:babel:orders:created", func(ctx context.Context, env babelqueue.Envelope) error {
    // handle env.Data ...
    return nil
})
app.Publish(ctx, "urn:babel:orders:created", map[string]any{"order_id": 1042})
app.Consume(ctx)

Bring your own client with redis.NewWithClient(client) (custom pool / TLS / auth). The BabelQueue core stays zero-dependency; this module is the only place go-redis is pulled in.

Out-of-band headers (traceparent, ADR-0028)

The transport implements the optional babelqueue.HeaderPublisher capability, so out-of-band transport headers — e.g. a W3C traceparent for cross-hop span linkage — ride beside the frozen wire envelope, never inside it. Redis stores only the raw list value (the LREM ack handle is that value), so there is no native per-message metadata channel; the transport instead owns a small JSON frame, distinct from the wire envelope:

{"__bq_frame":1,"headers":{"traceparent":"00-…-01"},"body":"<raw wire envelope>"}

• Publish stores the bare envelope byte-for-byte (no frame).
• PublishWithHeaders writes a frame only when the header map is non-empty; with no usable headers it degrades to a byte-identical bare Publish.
• Pop detects frame-vs-bare by the reserved __bq_frame sentinel (the frozen envelope never carries it). A frame is unwrapped — Body is the raw envelope, Headers carries the frame's headers; the Handle stays the stored frame, so the reliable-queue RPUSH/BLMOVE/LREM semantics are untouched. A bare value (an older or non-otel publisher, or a cross-version queue) consumes exactly as before: Headers is nil and the handle is the bare value.

Full spec: babelqueue.com · MIT © Muhammet Şafak