Create packages client/internal/ retry and lhttp.

client/internal/common/json.go

Index: client/internal/common/json.go
diff --git a/client/internal/common/json.go b/client/internal/common/json.go
index e1907febe02e97e482fb97e81496708d9b6aa5c6..25819886a472fb5cb3f2a7ccd7e4c18b2f917dc7 100644
--- a/client/internal/common/json.go
+++ b/client/internal/common/json.go
@@ -5,71 +5,11 @@
 package common
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
-	"net/http"
 	"os"
-	"strings"
 )
 
-const jsonContentType = "application/json; charset=utf-8"
-
-// GetJSON does a simple HTTP GET on a JSON endpoint.
-//
-// Returns the status code and the error, if any.
-func GetJSON(c *http.Client, url string, out interface{}) (int, error) {
-	if c == nil {
-		c = http.DefaultClient
-	}
-	resp, err := c.Get(url)
-	if err != nil {
-		return 0, fmt.Errorf("couldn't resolve %s: %s", url, err)
-	}
-	return decodeJSONResponse(resp, url, out)
-}
-
-// PostJSON does a HTTP POST on a JSON endpoint.
-//
-// Returns the status code and the error, if any.
-func PostJSON(c *http.Client, url string, in, out interface{}) (int, error) {
-	if c == nil {
-		c = http.DefaultClient
-	}
-	if in == nil {
-		in = map[string]string{}
-	}
-	encoded, err := json.Marshal(in)
-	if err != nil {
-		return 0, nil
-	}
-	resp, err := c.Post(url, jsonContentType, bytes.NewBuffer(encoded))
-	if err != nil {
-		return 0, fmt.Errorf("couldn't resolve %s: %s", url, err)
-	}
-	return decodeJSONResponse(resp, url, out)
-}
-
-func decodeJSONResponse(resp *http.Response, url string, out interface{}) (int, error) {
-	defer resp.Body.Close()
-	if out == nil {
-		// The client doesn't care about the response. Still ensure the response is
-		// valid json.
-		out = &map[string]interface{}{}
-	}
-	if err := json.NewDecoder(resp.Body).Decode(out); err != nil {
-		return resp.StatusCode, fmt.Errorf("bad response %s: %s", url, err)
-	}
-	ct := strings.ToLower(resp.Header.Get("Content-Type"))
-	if ct != jsonContentType {
-		return resp.StatusCode, fmt.Errorf("unexpected Content-Type, expected \"%s\", got \"%s\"", jsonContentType, ct)
-	}
-	if resp.StatusCode >= 400 {
-		return resp.StatusCode, fmt.Errorf("http status %d", resp.StatusCode)
-	}
-	return resp.StatusCode, nil
-}
-
 // ReadJSONFile reads a file and decode it as JSON.
 func ReadJSONFile(filePath string, object interface{}) error {
 	f, err := os.Open(filePath)