About Metrics, Logging and Tracing with Flamingo

1. Flamingo in Production

2. Contents
• Compilation / CI
• Deployment Artifacts
• Metrics
• Tracing
• Logging

3. Compilation / CI
• Go: standalone Binary, no external dependencies
• GOOS=linux
• GOARCH=amd64
• CGO_ENABLED=0
• CI:
• go test -race -vet=all ./...

4. Running Flamingo
• Behind a Load Balancer
• Nginx
• Kubernetes Ingress
• New: Caddy builtin
• Auto TLS (Letsencrypt)
• config/Caddyfile support

5. Deployment Artifacts
• Bundle:
• Config Files
• (Templates)
• Artifact:
• Docker
• Tarball/Zipball

6. example/dist/Dockerfile
# Builder
FROM golang:alpine AS builder
RUN apk update && apk add --no-cache ca-certificates tzdata git
&& update-ca-certificates
COPY . /app
RUN cd /app && CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o app .
# Final image
FROM scratch
# add timezone data and ssl root certificates
COPY --from=builder /usr/share/zoneinfo /usr/share/zoneinfo
COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
# add artifacts
#ADD config /config
# add binary
COPY --from=builder /app/app /app
ENTRYPOINT ["/app"]
CMD ["serve"]

7. Running/Operating
Flamingo

8. Logging
• inject flamingo.Logger
• Based on Uber's ZAP logger
• JSON
• colors
• tags

9. OpenCensus

10. OpenCensus
• Metrics
• Served on a different port (13210 via systemendpoint
module)
• Tracing
• Pushed to Jaeger/Zipkin

11. Metrics• Time Series
• Prometheus

12. Tracing
• Opencensus
• Trace: Operation spanning multiple applications
• Span: Isolated operation, can have multiple children
• Trace Propagation:
• B3-Header
• W3 Trace Context

13. Tracing
• Exporter
• Jaeger
• Zipkin
• (Stackdriver)
• (AWS XRay)

14. Hands On

15. Hands On
• Checkout ...
• make jaeger
• go run . serve

16. Add a metric
var measure = stats.Int64("mymeasure", "my measure",
stats.UnitMilliseconds)
func init() {
view.SetReportingPeriod(100 * time.Millisecond)
opencensus.View(
"mymetric",
measure,
view.Distribution(1, 10, 100, 250, 500),
)
}

17. Collect a metric
stats.Record(ctx, measure.M(int64(n)))

18. Add a trace
ctx, span := trace.StartSpan(ctx, "my/span")
defer span.End()

19. Log information
type controller struct {
logger flamingo.Logger
}
func (c *controller) Inject(logger flamingo.Logger) {
c.logger = logger
}
func (c *controller) action(ctx context.Context, req *web.Request) web.Result {
c.logger.WithField("duration", n).Info("sleeping")
}