goagent

README

Go Agent

goagent provides a set of complementary instrumentation features for collecting relevant data to be processed by Hypertrace.

Getting started

Setting up Go Agent can be done with a few lines:

import "github.com/hypertrace/goagent/config"

...

func main() {
    cfg := config.Load()
    cfg.ServiceName = config.String("myservice")

    shutdown := hypertrace.Init(cfg)
    defer shutdown
}

Config values can be declared in config file, env variables or code. For further information about config check this section.

Package net/hyperhttp

HTTP server

The server instrumentation relies on the http.Handler component of the server declarations.

import (
    "net/http"

    "github.com/gorilla/mux"
    "github.com/hypertrace/goagent/instrumentation/hypertrace/net/hyperhttp"
)

func main() {
    // ...

    r := mux.NewRouter()
    r.Handle("/foo/{bar}", hyperhttp.NewHandler(
        fooHandler,
        "/foo/{bar}",
    ))

    // ...
}

Options

Filter

Filtering can be added as part of options. Multiple filters can be added and they will be run in sequence until a filter returns true (request is blocked), or all filters are run.

// ...

    r.Handle("/foo/{bar}", hyperhttp.NewHandler(
        fooHandler,
        "/foo/{bar}",
        hyperhttp.WithFilter(filter.NewMultiFilter(filter1, filter2)),
    ))

// ...

HTTP client

The client instrumentation relies on the http.Transport component of the HTTP client in Go.

import (
    "net/http"
    "github.com/hypertrace/goagent/instrumentation/hypertrace/net/hyperhttp"
)

// ...

client := http.Client{
    Transport: hyperhttp.NewTransport(
        http.DefaultTransport,
    ),
}

req, _ := http.NewRequest("GET", "http://example.com", nil)

res, err := client.Do(req)

// ...

Running HTTP examples

In terminal 1 run the client:

go run ./examples/http-client/main.go

In terminal 2 run the server:

go run ./examples/http-server/main.go

Gin-Gonic Server

Gin server instrumentation relies on adding the hypergin.Middleware middleware to the gin server.

r := gin.Default()

cfg := config.Load()
cfg.ServiceName = config.String("http-gin-server")

flusher := hypertrace.Init(cfg)
defer flusher()

r.Use(hypergin.Middleware())

To run an example gin server with the hypertrace middleware:

go run ./examples/gin-server/main.go

Then make a request to localhost:8080/ping

Package google.golang.org/hypergrpc

GRPC server

The server instrumentation relies on the grpc.UnaryServerInterceptor component of the server declarations.

server := grpc.NewServer(
    grpc.UnaryInterceptor(
        hypergrpc.UnaryServerInterceptor(),
    ),
)

Options

Filter

Filtering can be added as part of options. Multiple filters can be added and they will be run in sequence until a filter returns true (request is blocked), or all filters are run.

// ...

    grpc.UnaryInterceptor(
        hypergrpc.UnaryServerInterceptor(
            hypergrpc.WithFilter(filter.NewMultiFilter(filter1, filter2))
        ),
    ),

// ...

GRPC client

The client instrumentation relies on the http.Transport component of the HTTP client in Go.

import (
    // ...

    hypergrpc "github.com/hypertrace/goagent/instrumentation/hypertrace/google.golang.org/hypergrpc"
    "google.golang.org/grpc"
)

func main() {
    // ...
    conn, err := grpc.Dial(
        address,
        grpc.WithInsecure(),
        grpc.WithBlock(),
        grpc.WithUnaryInterceptor(
            hypergrpc.UnaryClientInterceptor(),
        ),
    )
    if err != nil {
        log.Fatalf("could not dial: %v", err)
    }
    defer conn.Close()

    client := pb.NewCustomClient(conn)

    // ...
}

Running GRPC examples

In terminal 1 run the client:

go run ./examples/grpc-client/main.go

In terminal 2 run the server:

go run ./examples/grpc-server/main.go

Other instrumentations

• database/hypersql
• github.com/gorilla/hypermux

Contributing

Running tests

Tests can be run with (requires docker)

make test

for unit tests only

make test-unit

Releasing

Run ./release.sh <version_number> (<version_number> should follow semver, e.g. 1.2.3). The script will change the hardcoded version, commit it, push a tag and prepare the hardcoded version for the next release. After that go to the releases page and draft a new release based on the new tag.

Further Reference

Read more about goagent in the 'Yet Another Go Agent' blog post.