Recap: Automatically Instrument Your Go Source Code with Orchestrion

https://mercari.connpass.com/event/299331/

Transcript

1. 1 Recap: Automatically Instrument Your Go Source Code with Orchestrion mercari.go #24 - GopherCon 2023 Recap Shunta Komatsu
2. 2 About me • Shunta Komatsu • Backend Engineer at Merpay ◦ Developing the payment platform • Joined Merpay in April 2022
3. 3 What kind of presentation? https://www.gophercon.com/agenda/session/1160499
4. 4 What kind of presentation? Introduction of a tool “Orchestrion” developed by Datadog • The tool generates Datadog APM traces in Go code • More of code instrumentation rather than code generation • https://github.com/DataDog/orchestrion
5. 5 What is traces? • Traces show the flow of data within and between the components • A trace has one or more span(s) • Span is a section of interesting activity in your program ◦ receiving an HTTP request, calling in database, etc. https://www.datadoghq.com/product/apm/
6. 6 • Just adding some code How to gather data?
7. 7 • You need to set up all traces • You have to make sure you properly close your traces and spans When you add handlers
8. 8 Motivations behind orchestrion • Go doesn’t do magic ◦ Java provides “annotation” ◦ Python provides “decorator” • Instead, Go is simple and easy to parse the AST • Orchestrion generates code to add traces and spans https://docs.datadoghq.com/tracing/trace_collection/custom_instrumentation/python/ https://docs.datadoghq.com/tracing/trace_collection/custom_instrumentation/java/
9. 9 Demo of Orchestrion 1. Prepare the initial code 2. Run orchestrion -w .
10. 10 What does generated code do? • Launch the tracer • Stop the tracer as defer • Embed metadata package: github.com/orchestrion/instrument
11. 11 What does generated code do? package: github.com/orchestrion/instrument package: gopkg.in/DataDog/dd-trace-go.v1/contrib/net/http package: gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer
12. 12 (Appendix) What Is dd-trace-go.v1/contrib package? • https://github.com/DataDog/dd-trace-go/tree/main/contrib • A package to make tracer easier to use in various web frameworks, SQL frameworks, etc. ◦ gin-gonic/gin ◦ go-chi/chi ◦ labstack/echo ◦ net/http ◦ …
13. 13 Flexible usage • Orchestrion provides the –rm option ◦ You can revert to what it was before Orchestrion adde code • Any span tags can be set with dd:span magic comment
14. 14 How it works • Orchestrion scans each source code with the dave/dst package to get AST ◦ The standard go/ast package doesn’t attach comments to nodes
15. 15 Impressions of this session • Orchestrion is easy to use and reversible to change, and you’ll be able to try it out in no time • However, it still lacks functionality and would be especially difficult to apply to large repositories and microservices ◦ Ignore is not supported ◦ OpenTelemetry is not supported • The gopkg.in/DataDog/dd-trace-go.v1 package already has orchestrionConfig in the tracer.config struct, so the feature will be enhanced in the future
16. 16 Summary • Orchestrion installs the trace with just one line of command ◦ You don’t have to worry about forgetting to add spans • However, it may be better not to use it until more flexibility is brought to the functionality
17. 17 The Go gopher was designed by Renee French Thanks for your attention!