fchandler2go

A Go library that adapts Alibaba Cloud Function Compute (FC) HTTP handlers to work with the Gin web framework. This allows you to write your handlers once in the FC style and use them in both FC environments and regular Gin web applications.

Installation

go get github.com/danvei233/fchandler2go

Features

• Convert Gin HTTP requests to Alibaba Cloud Function Compute HTTP trigger events
• Convert FC HTTP responses back to Gin responses
• Support for various input and output types
• Automatic validation of handler function signatures
• Support for base64 encoded request/response bodies

Usage

Basic Example

package main

import (
    "github.com/aliyun/fc-runtime-go-sdk/events"
    "github.com/danvei233/fchandler2go"
    "github.com/gin-gonic/gin"
    "net/http"
)

func main() {
    router := gin.Default()

    // Register your FC-style handler with Gin
    router.Any("/*all", handler2gin.T(HandleRequest))

    router.Run(":8080")
}

// FC-style handler function
func HandleRequest(event events.HTTPTriggerEvent) (*events.HTTPTriggerResponse, error) {
    // Process the event

    // Return a response
    return &events.HTTPTriggerResponse{
        StatusCode: http.StatusOK,
        Headers: map[string]string{
            "Content-Type": "application/json",
        },
        Body: `{"message": "Hello, World!"}`,
        IsBase64Encoded: false,
    }, nil
}

Advanced Example with Context

package main

import (
    "context"
    "github.com/aliyun/fc-runtime-go-sdk/events"
    "github.com/danvei233/fchandler2go"
    "github.com/gin-gonic/gin"
    "net/http"
)

func main() {
    router := gin.Default()

    // Register your FC-style handler with Gin
    router.Any("/api/*path", handler2gin.T(HandleRequestWithContext))

    router.Run(":8080")
}

// FC-style handler function with context
func HandleRequestWithContext(ctx context.Context, event events.HTTPTriggerEvent) (*events.HTTPTriggerResponse, error) {
    // Use context if needed

    // Process the event

    // Return a response
    return &events.HTTPTriggerResponse{
        StatusCode: http.StatusOK,
        Headers: map[string]string{
            "Content-Type": "application/json",
        },
        Body: `{"message": "Hello with context!"}`,
        IsBase64Encoded: false,
    }, nil
}

Configuration Options

package main

import (
	"github.com/aliyun/fc-runtime-go-sdk/events"
	"github.com/danvei233/fchandler2go"
	"github.com/danvei233/fchandler2go/AliyunWebFC/config"
	"github.com/gin-gonic/gin"
)

func main() {
	router := gin.Default()

	// Configure the handler with options
	cfg := config.Config{
		Output: config.Output{
			RequestIDFromMock: true,
		},
	}

	router.Any("/*all", handler2gin.T(HandleRequest, cfg))

	router.Run(":8080")
}

func HandleRequest(event events.HTTPTriggerEvent) (*events.HTTPTriggerResponse, error) {
	// Handler implementation
	// ...
}

Calling Process

The following diagram illustrates the calling process when using fchandler2go:

sequenceDiagram
    participant Client
    participant Gin as Gin Router
    participant T as handler2gin.T
    participant Reflector as Reflector
    participant ConvertRequest as ConvertRequest
    participant Handler as Your FC Handler
    participant Recall as Recall

    Client->>Gin: HTTP Request
    Gin->>T: Call handler function
    T->>Reflector: NewReflector(handler)
    Reflector-->>T: Reflector instance
    T->>Reflector: CheckValid()
    Reflector-->>T: Validation result

    T->>ConvertRequest: ConvertRequest(ginContext, config)
    ConvertRequest-->>T: events.HTTPTriggerEvent

    T->>Reflector: Invoke(ctx, event)
    Reflector->>Handler: Call with appropriate args
    Handler-->>Reflector: Return response and error
    Reflector-->>T: Return response and error

    T->>Recall: Recall(ginContext, response, config)
    Recall->>Gin: Write response to Gin context
    Gin-->>Client: HTTP Response

Loading

Supported Handler Signatures

The library supports the following handler function signatures:

1. func(events.HTTPTriggerEvent) (*events.HTTPTriggerResponse, error)
2. func(context.Context, events.HTTPTriggerEvent) (*events.HTTPTriggerResponse, error)
3. func() (*events.HTTPTriggerResponse, error)
4. func(context.Context) (*events.HTTPTriggerResponse, error)

License

[License information]