:chore: implemented transport file to make the OSC API Connection

builder/osc/common/transport.go

@@ -0,0 +1,60 @@
+package common
+
+import (
+	"io/ioutil"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws/credentials"
+	v4 "github.com/aws/aws-sdk-go/aws/signer/v4"
+)
+
+// Transport is used to sing the user for each request
+type Transport struct {
+	transport http.RoundTripper
+	signer    *v4.Signer
+	region    string
+}
+
+func (t *Transport) sign(req *http.Request, body []byte) error {
+	reader := strings.NewReader(string(body))
+	timestamp := time.Now()
+	_, err := t.signer.Sign(req, reader, "osc", t.region, timestamp)
+	return err
+}
+
+// RoundTrip is implemented according with the interface RoundTrip to sing for each request
+func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
+	//Get the body
+	getBody := req.GetBody
+	copyBody, err := getBody()
+	if err != nil {
+		return nil, err
+	}
+
+	body, err := ioutil.ReadAll(copyBody)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := t.sign(req, body); err != nil {
+		return nil, err
+	}
+
+	resp, err := t.transport.RoundTrip(req)
+	if err != nil {
+		return resp, err
+	}
+
+	return resp, nil
+}
+
+// NewTransport returns the transport signing with the given credentials
+func NewTransport(accessKey, accessSecret, region string, t http.RoundTripper) *Transport {
+	s := &v4.Signer{
+		Credentials: credentials.NewStaticCredentials(accessKey,
+			accessSecret, ""),
+	}
+	return &Transport{t, s, region}
+}