FusionAuth Go Client

Go Client Library

The Go client library allows you to integrate FusionAuth with your Go application.

Source Code:

• https://github.com/FusionAuth/go-client

go mod init example.com/test/fusionauth
go mod tidy

package main

import (
    "net/http"
    "net/url"
    "time"
    "fmt"

    "github.com/FusionAuth/go-client/pkg/fusionauth"
)

const host = "http://localhost:9011"

var apiKey = "YOUR_API_KEY"

var httpClient = &http.Client{
	Timeout: time.Second * 10,
}

var baseURL, _ = url.Parse(host)

// Construct a new FusionAuth Client
var client = fusionauth.NewClient(httpClient, baseURL, apiKey)

func main() {
    response, errors, err := client.RetrieveUserByEmail("user@example.com")
    if err != nil {
        // err is a transport layer error (connection failed, etc)
        fmt.Println(err)
        return
    }
    if errors != nil {
        // err is a FusionAuth response error (user couldn't be found, etc)
        fmt.Println(response.StatusCode)
        return
    }
    fmt.Println(response.User.Email)
    fmt.Println(response.User.FirstName)
    fmt.Println(response.User.LastName)
}

go build

./fusionauth

PATCH requests

PATCH requests are handled differently than you might expect. PATCH operations allow you to modify only parts of an object in FusionAuth.

In client libraries with static typing, such as this one for Go, there are no strongly typed objects set as part of a PATCH request. Instead, a hash, dictionary or map object is used. Ensure that you are using multi level dictionaries that create JSON with nested keys, otherwise the PATCH request will fail. This allows use of key value pairs to build a PATCH request.

For example, if you want to change only the name of an application using PATCH, you would want the JSON that is sent across the wire to look like this:

{
  "application": {
     "name": "hooli-bought-us"
   }
}

If you built a typed application request object and then serialized it, it would contain empty arrays or other default values. This would modify the object you were changing in ways you didn’t expect. This would likely cause the system behave in ways you don’t want.

By requiring you to build nested key value pairs, the JSON serialization works correctly. This is essentially a limitation of the current implementation in Go and FusionAuth PATCH support.

For this behavior to work correctly with typed objects, FusionAuth would need to ensure the domain object had no default values, and then instruct the serializer to omit empty objects, empty arrays and other values from the resulting JSON. This would ensure that the PATCH was performed correctly with no unwanted side effects.

Once support for RFC 7396 lands in FusionAuth, there may be some additional options for configuring a JSON serializer to allow use of typed domain objects for PATCH.

An alternative that allows you to use typed objects immediately is to perform a retrieve operation, modify the object in memory, and then execute an update operation. These are functionally equivalent to a single PATCH operation.