package google import ( "encoding/json" "fmt" "log" "net/http" "os" "code.google.com/p/goauth2/oauth" "code.google.com/p/goauth2/oauth/jwt" "code.google.com/p/google-api-go-client/compute/v1" ) const clientScopes string = "https://www.googleapis.com/auth/compute" // Config is the configuration structure used to instantiate the Google // provider. type Config struct { AccountFile string ClientSecretsFile string Project string Region string clientCompute *compute.Service } func (c *Config) loadAndValidate() error { var account accountFile var secrets clientSecretsFile if err := loadJSON(&account, c.AccountFile); err != nil { return fmt.Errorf( "Error loading account file '%s': %s", c.AccountFile, err) } if err := loadJSON(&secrets, c.ClientSecretsFile); err != nil { return fmt.Errorf( "Error loading client secrets file '%s': %s", c.ClientSecretsFile, err) } // Get the token for use in our requests log.Printf("[INFO] Requesting Google token...") log.Printf("[INFO] -- Email: %s", account.ClientEmail) log.Printf("[INFO] -- Scopes: %s", clientScopes) log.Printf("[INFO] -- Private Key Length: %d", len(account.PrivateKey)) log.Printf("[INFO] -- Token URL: %s", secrets.Web.TokenURI) jwtTok := jwt.NewToken( account.ClientEmail, clientScopes, []byte(account.PrivateKey)) jwtTok.ClaimSet.Aud = secrets.Web.TokenURI token, err := jwtTok.Assert(new(http.Client)) if err != nil { return fmt.Errorf("Error retrieving auth token: %s", err) } // Instantiate the transport to communicate to Google transport := &oauth.Transport{ Config: &oauth.Config{ ClientId: account.ClientId, Scope: clientScopes, TokenURL: secrets.Web.TokenURI, AuthURL: secrets.Web.AuthURI, }, Token: token, } log.Printf("[INFO] Instantiating GCE client...") c.clientCompute, err = compute.New(transport.Client()) if err != nil { return err } return nil } // accountFile represents the structure of the account file JSON file. type accountFile struct { PrivateKeyId string `json:"private_key_id"` PrivateKey string `json:"private_key"` ClientEmail string `json:"client_email"` ClientId string `json:"client_id"` } // clientSecretsFile represents the structure of the client secrets JSON file. type clientSecretsFile struct { Web struct { AuthURI string `json:"auth_uri"` ClientEmail string `json:"client_email"` ClientId string `json:"client_id"` TokenURI string `json:"token_uri"` } } func loadJSON(result interface{}, path string) error { f, err := os.Open(path) if err != nil { return err } defer f.Close() dec := json.NewDecoder(f) return dec.Decode(result) }