Loki integration

integration/loki ships server-side events to Grafana Loki via the Loki push API (protobuf + snappy compression). Useful for retaining a high-volume, queryable log of every event flowing through your collect endpoint.

Features

• Protobuf + snappy wire format — the efficient path Loki supports.
• Channel-based batching — events are queued and shipped in batches.
• Exponential backoff retry on transport errors.
• Lifecycle service — start/stop hooks for graceful shutdown (Service.Start / Service.Close).

Wire it as a service

import (
	"github.com/foomo/sesamy-go/integration/loki"
)

l, _ := zap.NewProduction()

lk := loki.New(l, loki.WithEndpoint("https://logs.example.com/loki/api/v1/push"))
svc := loki.NewService(lk)

// In your lifecycle manager:
go func() { _ = svc.Start(ctx) }()
defer svc.Close(ctx)

Plug into Collect

Wrap a Loki push in a middleware so every inbound event lands in Loki:

import (
	lokimw "github.com/foomo/sesamy-go/integration/loki"
)

collect.New(l,
	collect.WithTagging("https://sgtm.example.com"),
	collect.WithMPv2HTTPMiddlewares(
		lokimw.Middleware(lk), // see integration/loki/middleware.go
		mpv2http.MiddlewareLogger,
	),
)

Labels and lines

Each event becomes a Loki line with metadata labels (event name, measurement ID, client ID where available). The line format is defined in integration/loki/line.go and can be customized by replacing the line builder.

Operational notes

• Backpressure: the channel has a bounded buffer; if Loki is unreachable for too long, oldest events are dropped to keep the producer non-blocking. Tune the buffer size to your retention tolerance.
• Compression: snappy is mandatory for the Loki protobuf endpoint; do not disable it.
• Multi-tenancy: pass X-Scope-OrgID via a custom HTTP client / request options if your Loki is multi-tenant.