# Iris

> Instrument Iris Go applications with the Last9 Go Agent for automatic HTTP request tracing and metrics

Source: https://last9.io/docs/integrations/frameworks/go/iris/

Use the Last9 Go Agent to instrument your Iris application with automatic tracing and metrics. The agent implements the OTel propagation API for Iris natively — full OTel compliance with minimal code changes.

## Prerequisites

- Go 1.22 or higher
- Iris v12 (`github.com/kataras/iris/v12`)
- Last9 account with OTLP credentials

## Installation

1. **Install the Last9 Go Agent**

   ```bash
   go get github.com/last9/go-agent
   ```

2. **Set Environment Variables**

   ```bash
   export OTEL_SERVICE_NAME="your-iris-service"
   export OTEL_EXPORTER_OTLP_ENDPOINT="$last9_otlp_endpoint"
   export OTEL_EXPORTER_OTLP_HEADERS="Authorization=$last9_otlp_auth_header"
   export OTEL_TRACES_SAMPLER="always_on"
   export OTEL_RESOURCE_ATTRIBUTES="deployment.environment=production"
   ```

3. **Instrument your application**

**New application**

   Replace `iris.New()` with `irisagent.New()` — it returns an `*iris.Application` with the tracing middleware already attached:

   ```go
   package main

   import (
       "log"

       "github.com/kataras/iris/v12"
       agent "github.com/last9/go-agent"
       irisagent "github.com/last9/go-agent/instrumentation/iris"
   )

   func main() {
       if err := agent.Start(); err != nil {
           log.Fatalf("failed to start agent: %v", err)
       }
       defer agent.Shutdown()

       app := irisagent.New() // drop-in for iris.New()

       app.Get("/users", getUsers)
       app.Get("/users/{id}", getUser)

       app.Listen(":8080")
   }
   ```

**Existing application**

   Add the middleware to your existing Iris application:

   ```go
   package main

   import (
       "log"

       "github.com/kataras/iris/v12"
       agent "github.com/last9/go-agent"
       irisagent "github.com/last9/go-agent/instrumentation/iris"
   )

   func main() {
       if err := agent.Start(); err != nil {
           log.Fatalf("failed to start agent: %v", err)
       }
       defer agent.Shutdown()

       app := iris.New()
       app.Use(irisagent.Middleware())

       app.Get("/users", getUsers)
       app.Listen(":8080")
   }
   ```

## Database Instrumentation

Use the agent's database integration for automatic SQL query tracing. Supported drivers: PostgreSQL, MySQL, SQLite.

```go
import (
    "log"

    "github.com/last9/go-agent/integrations/database"
)

var db *sql.DB

func init() {
    var err error
    db, err = database.Open(database.Config{
        DriverName:   "postgres",
        DSN:          "postgres://user:pass@localhost/mydb",
        DatabaseName: "mydb",
    })
    if err != nil {
        log.Fatal(err)
    }
}

// Pass ctx.Request().Context() to propagate the trace
func getUser(ctx iris.Context) {
    rows, err := db.QueryContext(ctx.Request().Context(), "SELECT id, name FROM users WHERE id = $1", ctx.Params().Get("id"))
    // ...
}
```

## Redis Instrumentation

```go
import redisagent "github.com/last9/go-agent/integrations/redis"

// Drop-in replacement for redis.NewClient()
rdb := redisagent.NewClient(&redis.Options{
    Addr: "localhost:6379",
})

func getFromCache(ctx iris.Context) {
    val, err := rdb.Get(ctx.Request().Context(), "key").Result()
    // ...
}
```

## HTTP Client Instrumentation

For outgoing requests with automatic `traceparent` propagation:

```go
import httpagent "github.com/last9/go-agent/integrations/http"

client := httpagent.NewClient(&http.Client{})

func callUpstream(ctx iris.Context) {
    req, _ := http.NewRequestWithContext(ctx.Request().Context(), "GET", "https://api.example.com/data", nil)
    resp, err := client.Do(req)
    // ...
}
```

## What Gets Traced Automatically

| Signal  | What's captured                                                    |
| ------- | ------------------------------------------------------------------ |
| Traces  | Every HTTP request: method, route pattern, status code, latency    |
| Traces  | Database queries: SQL statement, db system, server address/port    |
| Traces  | Redis commands: command name, key                                  |
| Traces  | Outbound HTTP: method, URL, status code                            |
| Metrics | Runtime: memory, GC pause, goroutine count                         |
| Metrics | HTTP: request duration, request/response sizes, active connections |
| Metrics | Database: connection pool usage, idle, wait time                   |

## View Traces and Metrics

After running your application, navigate to [Trace Explorer](https://app.last9.io/traces) and [Metrics Explorer](https://app.last9.io/metrics) in Last9 to view your telemetry data.

---

## Troubleshooting

Please get in touch with us on [Discord](https://discord.com/invite/Q3p2EEucx9) or [Email](mailto:support@last9.io) if you have any questions.