Orchestrion

Automatic instrumentation of Go code

Getting started

1. Install Orchestrion

go install github.com/jonbodner/orchestrion

2. Let Orchestrion scan the codebase and rewrite it

orchestrion -w ./

3. Check-in the modified code! You might need to run go get github.com/jonbodner/orchestrion and go mod tidy if it's the first time you add orchestrion to your Go project.

What it does

Orchestrion processes Go source code and automatically inserts instrumentation.

How it works

The source code package tree is scanned. For each source code file, use dave/dst to build an AST of the source code in the file.

The AST is checked for package level functions or methods that have a //dd:span comment attached to them. A function or method annotated with //dd:span must meet an additional condition in order for a span to be automatically inserted into the code. Passing trace information through a Go program requires a context to be present. In order to pass the context through the code, either the first parameter of the function or method must be of type context.Context or there must be a parameter of type *http.Request (the context can be passed via a field in *http.Request). If both conditions are met, the //dd:span comment is scanned for tags and code is inserted as the first lines of the function.

Orchestrion also supports automatic tracing of the following libraries:

• net/http
• database/sql
• google.golang.org/grpc
• Support compile-time auto-instrumentation via -toolexec

Next steps

• Support auto-instrumenting more third-party libraries