Add credentials find command (#92)

Implement a command to give users information about which credentials would be used by the cloud-cli in the current folder

Author: Paolo Calao

README.md

@@ -55,6 +55,12 @@ Credentials file is supported in two different format: json and yaml. Use the `-
 
 It is also possible to specify credentials directly in `ARDUINO_CLOUD_CLIENT` and `ARDUINO_CLOUD_SECRET` environment variables. Credentials specified in environment variables have higher priority than the ones specified in credentials files.
 
+#### Find credentials
+
+To have information about which credentials would be used in the current folder you can use the following command:
+
+`$ arduino-cloud-cli credentials find`
+
 ## Device provisioning
 
 When provisioning a device, you can optionally specify the port to which the device is connected to and its fqbn. If they are not given, then the first device found will be provisioned.

cli/credentials/credentials.go

@@ -29,6 +29,7 @@ func NewCommand() *cobra.Command {
 	}
 
 	credentialsCommand.AddCommand(initInitCommand())
+	credentialsCommand.AddCommand(initFindCommand())
 
 	return credentialsCommand
 }

cli/credentials/find.go

@@ -0,0 +1,51 @@
+// This file is part of arduino-cloud-cli.
+//
+// Copyright (C) 2021 ARDUINO SA (http://www.arduino.cc/)
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package credentials
+
+import (
+	"os"
+
+	"github.com/arduino/arduino-cli/cli/errorcodes"
+	"github.com/arduino/arduino-cli/cli/feedback"
+	"github.com/arduino/arduino-cloud-cli/internal/config"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+)
+
+func initFindCommand() *cobra.Command {
+	findCommand := &cobra.Command{
+		Use:   "find",
+		Short: "Find the credentials that would be used in your current directory",
+		Long:  "Find the credentials to access Arduino IoT Cloud that would be used in your current directory",
+		Run:   runFindCommand,
+	}
+
+	return findCommand
+}
+
+func runFindCommand(cmd *cobra.Command, args []string) {
+	logrus.Info("Looking for credentials")
+
+	src, err := config.FindCredentials()
+	if err != nil {
+		feedback.Errorf("Error during credentials find: %v", err)
+		os.Exit(errorcodes.ErrGeneric)
+	}
+
+	feedback.Printf("Using credentials in: %s", src)
+}

internal/config/config.go

@@ -24,42 +24,40 @@ import (
 	"github.com/spf13/viper"
 )
 
-// searchConfigDir looks for a configuration file in different directories in the following order:
+// searchConfigFile looks for a configuration file in different directories in the following order:
 // current working directory, parents of the current working directory, arduino15 default directory.
-// Returns a nil string if no config file has been found, without raising errors.
+// Returns empty string and false if no config file has been found, without raising errors.
 // Returns an error if any problem is encountered during the file research which prevents
 // to understand whether a config file exists or not.
-func searchConfigDir(confname string) (*string, error) {
+func searchConfigFile(confname string) (dir string, found bool, err error) {
 	// Search in current directory and its parents.
 	cwd, err := paths.Getwd()
 	if err != nil {
-		return nil, err
+		return "", false, err
 	}
 	// Don't let bad naming mislead you, cwd.Parents()[0] is cwd itself so
 	// we look in the current directory first and then on its parents.
 	for _, path := range cwd.Parents() {
 		logrus.Infof("Looking for %s in %s", confname, path)
 		if file, found := configFileInDir(confname, path); found {
 			logrus.Infof("Found %s at %s", confname, file)
-			p := path.String()
-			return &p, nil
+			return file.String(), true, nil
 		}
 	}
 
 	// Search in arduino's default data directory.
 	arduino15, err := arduino.DataDir()
 	if err != nil {
-		return nil, err
+		return "", false, err
 	}
 	logrus.Infof("Looking for %s in %s", confname, arduino15)
 	if file, found := configFileInDir(confname, arduino15); found {
 		logrus.Infof("%s found at %s", confname, file)
-		p := arduino15.String()
-		return &p, nil
+		return file.String(), true, nil
 	}
 
 	// Didn't find config file in the current directory, its parents or in arduino15"
-	return nil, nil
+	return "", false, nil
 }
 
 // configFileInDir looks for a configuration file in the passed directory.

internal/config/credentials.go

@@ -19,7 +19,9 @@ package config
 
 import (
 	"fmt"
+	"strings"
 
+	"github.com/arduino/go-paths-helper"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/viper"
 )
@@ -38,8 +40,8 @@ const (
 	CredentialsFilename = "arduino-cloud-credentials"
 )
 
-// SetDefaultCredentials sets the default credentials values.
-func SetDefaultCredentials(settings *viper.Viper) {
+// SetEmptyCredentials sets the default credentials values to empty strings.
+func SetEmptyCredentials(settings *viper.Viper) {
 	// Client ID
 	settings.SetDefault("client", "")
 	// Secret
@@ -77,89 +79,110 @@ func (c *Credentials) IsEmpty() bool {
 	return len(c.Client) == 0 && len(c.Secret) == 0
 }
 
-// RetrieveCredentials looks for credentials in
+// FindCredentials looks for credentials in
 // environment variables or in credentials file.
-// Returns error if no credentials are found.
-func RetrieveCredentials() (*Credentials, error) {
+// Returns the source of found credentials (env or filepath).
+// Returns an error if credentials are not found
+// specifying paths where the credentials are searched.
+func FindCredentials() (source string, err error) {
 	// Credentials extracted from environment has highest priority
 	logrus.Info("Looking for credentials in environment variables")
 	c, err := fromEnv()
 	if err != nil {
-		return nil, fmt.Errorf("reading credentials from environment variables: %w", err)
+		return "", fmt.Errorf("looking for credentials in environment variables: %w", err)
 	}
-	// Return credentials only if found
-	if c != nil {
-		logrus.Info("Credentials found in environment variables")
-		return c, nil
+	if !c.IsEmpty() {
+		logrus.Infof("Credentials found in environment variables with prefix '%s'", EnvPrefix)
+		return "environment variables", nil
 	}
 
 	logrus.Info("Looking for credentials in file system")
-	c, err = fromFile()
+	path, found, err := searchConfigFile(CredentialsFilename)
 	if err != nil {
-		return nil, fmt.Errorf("reading credentials from file: %w", err)
+		return "", fmt.Errorf("looking for credentials files: %w", err)
 	}
-	if c != nil {
-		return c, nil
+	if found {
+		return path, nil
 	}
 
-	return nil, fmt.Errorf(
+	return "", fmt.Errorf(
 		"credentials have not been found neither in environment variables " +
 			"nor in the current directory, its parents or in arduino15",
 	)
 }
 
-// fromFile looks for a credentials file.
-// If a credentials file is not found, it returns nil credentials without raising errors.
-// If invalid credentials file is found, it returns an error.
-func fromFile() (*Credentials, error) {
-	// Looks for a credentials file
-	configDir, err := searchConfigDir(CredentialsFilename)
+// RetrieveCredentials retrieves credentials from
+// environment variables or credentials file.
+// Returns error if credentials are not found or
+// if found credentials are invalid.
+func RetrieveCredentials() (cred *Credentials, err error) {
+	// Credentials extracted from environment has highest priority
+	logrus.Info("Looking for credentials in environment variables")
+	cred, err = fromEnv()
+	if err != nil {
+		return nil, fmt.Errorf("reading credentials from environment variables: %w", err)
+	}
+	// Returns credentials if found in env
+	if !cred.IsEmpty() {
+		// Returns error if credentials are found but are not valid
+		if err := cred.Validate(); err != nil {
+			return nil, fmt.Errorf(
+				"credentials retrieved from environment variables with prefix '%s' are not valid: %w", EnvPrefix, err,
+			)
+		}
+		logrus.Infof("Credentials found in environment variables with prefix '%s'", EnvPrefix)
+		return cred, nil
+	}
+
+	logrus.Info("Looking for credentials in file system")
+	filepath, found, err := searchConfigFile(CredentialsFilename)
 	if err != nil {
 		return nil, fmt.Errorf("can't get credentials directory: %w", err)
 	}
-	// Return nil credentials if no config file is found
-	if configDir == nil {
-		return nil, nil
+	// Returns credentials if found in a file
+	if found {
+		if cred, err = fromFile(filepath); err != nil {
+			return nil, fmt.Errorf("reading credentials from file %s: %w", filepath, err)
+		}
+		// Returns error if credentials are found but are not valid
+		if err := cred.Validate(); err != nil {
+			return nil, fmt.Errorf(
+				"credentials retrieved from file %s are not valid: %w", filepath, err,
+			)
+		}
+		return cred, nil
 	}
 
+	return nil, fmt.Errorf(
+		"credentials have not been found neither in environment variables " +
+			"nor in the current directory, its parents or in arduino15",
+	)
+}
+
+// fromFile retrieves credentials from a credentials file.
+// Returns error if credentials are not found or cannot be fetched.
+func fromFile(filepath string) (*Credentials, error) {
 	v := viper.New()
-	v.SetConfigName(CredentialsFilename)
-	v.AddConfigPath(*configDir)
-	err = v.ReadInConfig()
+	v.SetConfigFile(filepath)
+	v.SetConfigType(strings.TrimLeft(paths.New(filepath).Ext(), "."))
+	err := v.ReadInConfig()
 	if err != nil {
-		err = fmt.Errorf(
-			"credentials file found at %s but cannot read its content: %w",
-			*configDir,
-			err,
-		)
-		return nil, err
+		return nil, fmt.Errorf("cannot read credentials file: %w", err)
 	}
 
 	cred := &Credentials{}
 	err = v.Unmarshal(cred)
 	if err != nil {
-		return nil, fmt.Errorf(
-			"credentials file found at %s but cannot unmarshal it: %w",
-			*configDir,
-			err,
-		)
-	}
-	if err = cred.Validate(); err != nil {
-		return nil, fmt.Errorf(
-			"credentials file found at %s but is not valid: %w",
-			*configDir,
-			err,
-		)
+		return nil, fmt.Errorf("cannot unmarshal credentials file: %w", err)
 	}
 	return cred, nil
 }
 
-// fromEnv looks for credentials in environment variables.
-// If credentials are not found, it returns nil credentials without raising errors.
-// If invalid credentials are found, it returns an error.
+// fromEnv retrieves credentials from environment variables.
+// Returns empty credentials if not found.
 func fromEnv() (*Credentials, error) {
 	v := viper.New()
-	SetDefaultCredentials(v)
+	SetEmptyCredentials(v)
 	v.SetEnvPrefix(EnvPrefix)
 	v.AutomaticEnv()
 
@@ -168,17 +191,5 @@ func fromEnv() (*Credentials, error) {
 	if err != nil {
 		return nil, fmt.Errorf("cannot unmarshal credentials from environment variables: %w", err)
 	}
-
-	if cred.IsEmpty() {
-		return nil, nil
-	}
-
-	if err = cred.Validate(); err != nil {
-		return nil, fmt.Errorf(
-			"credentials retrieved from environment variables with prefix '%s' are not valid: %w",
-			EnvPrefix,
-			err,
-		)
-	}
 	return cred, nil
 }