added ability to login/register to the docker registry, via the docker login command

auth/auth.go

@@ -0,0 +1,136 @@
+package auth
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"strings"
+)
+
+// Where we store the config file
+const CONFIGFILE = "/var/lib/docker/.dockercfg"
+
+// the registry server we want to login against
+const REGISTRY_SERVER = "http://registry.docker.io"
+
+type AuthConfig struct {
+	Username string `json:"username"`
+	Password string `json:"password"`
+	Email    string `json:"email"`
+}
+
+// create a base64 encoded auth string to store in config
+func EncodeAuth(authConfig AuthConfig) string {
+	authStr := authConfig.Username + ":" + authConfig.Password
+	msg := []byte(authStr)
+	encoded := make([]byte, base64.StdEncoding.EncodedLen(len(msg)))
+	base64.StdEncoding.Encode(encoded, msg)
+	return string(encoded)
+}
+
+// decode the auth string
+func DecodeAuth(authStr string) (AuthConfig, error) {
+	decLen := base64.StdEncoding.DecodedLen(len(authStr))
+	decoded := make([]byte, decLen)
+	authByte := []byte(authStr)
+	n, err := base64.StdEncoding.Decode(decoded, authByte)
+	if err != nil {
+		return AuthConfig{}, err
+	}
+	if n > decLen {
+		return AuthConfig{}, errors.New("something went wrong decoding auth config")
+	}
+	arr := strings.Split(string(decoded), ":")
+	password := strings.Trim(arr[1], "\x00")
+	return AuthConfig{Username: arr[0], Password: password}, nil
+
+}
+
+// load up the auth config information and return values
+func LoadConfig() (AuthConfig, error) {
+	if _, err := os.Stat(CONFIGFILE); err == nil {
+		b, err := ioutil.ReadFile(CONFIGFILE)
+		if err != nil {
+			return AuthConfig{}, err
+		}
+		arr := strings.Split(string(b), "\n")
+		orig_auth := strings.Split(arr[0], " = ")
+		orig_email := strings.Split(arr[1], " = ")
+		authConfig, err := DecodeAuth(orig_auth[1])
+		if err != nil {
+			return AuthConfig{}, err
+		}
+		authConfig.Email = orig_email[1]
+		return authConfig, nil
+	} else {
+		return AuthConfig{}, nil
+	}
+	return AuthConfig{}, nil
+}
+
+// save the auth config
+func saveConfig(authStr string, email string) error {
+	lines := "auth = " + authStr + "\n" + "email = " + email + "\n"
+	b := []byte(lines)
+	err := ioutil.WriteFile(CONFIGFILE, b, 0600)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// try to register/login to the registry server
+func Login(authConfig AuthConfig) (string, error) {
+	storeConfig := false
+	reqStatusCode := 0
+	var status string
+	var reqBody []byte
+	jsonBody, _ := json.Marshal(authConfig)
+	b := strings.NewReader(string(jsonBody))
+	req1, err := http.Post(REGISTRY_SERVER+"/v1/users", "application/json; charset=utf-8", b)
+	if err == nil {
+		body, _ := ioutil.ReadAll(req1.Body)
+		reqStatusCode = req1.StatusCode
+		reqBody = body
+		req1.Body.Close()
+	} else {
+		return "", err
+	}
+	if reqStatusCode == 201 {
+		status = "Account Created\n"
+		storeConfig = true
+	} else if reqStatusCode == 400 {
+		if string(reqBody) == "Username or email already exist" {
+			client := &http.Client{}
+			req, err := http.NewRequest("GET", REGISTRY_SERVER+"/v1/users", nil)
+			req.SetBasicAuth(authConfig.Username, authConfig.Password)
+			resp, err := client.Do(req)
+			if err != nil {
+				return "", err
+			}
+			defer resp.Body.Close()
+			body, err := ioutil.ReadAll(resp.Body)
+			if err != nil {
+				return "", err
+			}
+			if resp.StatusCode == 200 {
+				status = "Login Succeeded\n"
+				storeConfig = true
+			} else {
+				storeConfig = false
+				status = fmt.Sprintf("Error: %s\n", body)
+			}
+		} else {
+			status = fmt.Sprintf("Error: %s\n", reqBody)
+		}
+	}
+	if storeConfig {
+		authStr := EncodeAuth(authConfig)
+		saveConfig(authStr, authConfig.Email)
+	}
+	return status, nil
+}