From 46f3c8e0e925cc2be527adc66c8934265b716205 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Samin?= <francois.samin@corp.ovh.com>
Date: Fri, 4 Aug 2023 10:56:27 +0200
Subject: [PATCH] feat: yaml binding (#96)

---
 go.mod         |  1 +
 go.sum         |  2 ++
 tonic/tonic.go | 43 +++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/go.mod b/go.mod
index dfc5976..e92cfbe 100644
--- a/go.mod
+++ b/go.mod
@@ -16,6 +16,7 @@ require (
 	github.com/pires/go-proxyproto v0.6.0
 	github.com/poy/onpar v1.1.2 // indirect
 	github.com/ziutek/mymysql v1.5.4 // indirect
+	sigs.k8s.io/yaml v1.3.0
 )
 
 go 1.13
diff --git a/go.sum b/go.sum
index b11291e..0707411 100644
--- a/go.sum
+++ b/go.sum
@@ -274,3 +274,5 @@ gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 launchpad.net/gocheck v0.0.0-20140225173054-000000000087/go.mod h1:hj7XX3B/0A+80Vse0e+BUHsHMTEhd0O4cpUHr/e/BUM=
 launchpad.net/xmlpath v0.0.0-20130614043138-000000000004/go.mod h1:vqyExLOM3qBx7mvYRkoxjSCF945s0mbe7YynlKYXtsA=
+sigs.k8s.io/yaml v1.3.0 h1:a2VclLzOGrwOHDiV8EfBGhvjHvP46CtW5j6POvhYGGo=
+sigs.k8s.io/yaml v1.3.0/go.mod h1:GeOyir5tyXNByN85N/dRIT9es5UQNerPYEKK56eTBm8=
diff --git a/tonic/tonic.go b/tonic/tonic.go
index 8bc9290..ce30e18 100644
--- a/tonic/tonic.go
+++ b/tonic/tonic.go
@@ -1,6 +1,7 @@
 package tonic
 
 import (
+	"bytes"
 	"encoding"
 	"errors"
 	"fmt"
@@ -15,6 +16,7 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/gin-gonic/gin/binding"
 	validator "github.com/go-playground/validator/v10"
+	"sigs.k8s.io/yaml" // sigs.k8s.io/yaml is the alternative to the unmaintained lib github.com/ghodss/yaml. cf https://github.com/ghodss/yaml/issues/80
 )
 
 // DefaultMaxBodyBytes is the maximum allowed size of a request body in bytes.
@@ -96,8 +98,15 @@ func DefaultBindingHookMaxBodyBytes(maxBodyBytes int64) BindHook {
 		if c.Request.ContentLength == 0 || c.Request.Method == http.MethodGet {
 			return nil
 		}
-		if err := c.ShouldBindWith(i, binding.JSON); err != nil && err != io.EOF {
-			return fmt.Errorf("error parsing request body: %s", err.Error())
+		switch c.Request.Header.Get("Content-Type") {
+		case "text/x-yaml", "text/yaml", "text/yml", "application/x-yaml", "application/x-yml", "application/yaml", "application/yml":
+			if err := c.ShouldBindWith(i, yamlBinding{}); err != nil && err != io.EOF {
+				return fmt.Errorf("error parsing request body: %s", err.Error())
+			}
+		default:
+			if err := c.ShouldBindWith(i, binding.JSON); err != nil && err != io.EOF {
+				return fmt.Errorf("error parsing request body: %s", err.Error())
+			}
 		}
 		return nil
 	}
@@ -443,3 +452,33 @@ func bindStringValue(s string, v reflect.Value) error {
 	}
 	return nil
 }
+
+// yamlBinding is an implementation of gin's binding.Binding
+// we don't use official gin's yamlBinding because we prefer to use github.com/ghodss/yaml
+type yamlBinding struct{}
+
+func (yamlBinding) Name() string {
+	return "yaml"
+}
+
+func (yamlBinding) Bind(req *http.Request, obj interface{}) error {
+	return decodeYAML(req.Body, obj)
+}
+
+func (yamlBinding) BindBody(body []byte, obj interface{}) error {
+	return decodeYAML(bytes.NewReader(body), obj)
+}
+
+func decodeYAML(r io.Reader, obj interface{}) error {
+	btes, err := io.ReadAll(r)
+	if err != nil {
+		return err
+	}
+	if err := yaml.Unmarshal(btes, &obj); err != nil {
+		return err
+	}
+	if binding.Validator == nil {
+		return nil
+	}
+	return binding.Validator.ValidateStruct(obj)
+}