Snippet of the NewAuthorizerFromFile function from the Azure GoLang SDK

NewAuthorizerFromFile.go

// NewAuthorizerFromFile creates an Authorizer configured from a configuration file.
func NewAuthorizerFromFile(baseURI string) (autorest.Authorizer, error) {
	fileLocation := os.Getenv("AZURE_AUTH_LOCATION")
	if fileLocation == "" {
		return nil, errors.New("auth file not found. Environment variable AZURE_AUTH_LOCATION is not set")
	}

	contents, err := ioutil.ReadFile(fileLocation)
	if err != nil {
		return nil, err
	}

	// Auth file might be encoded
	decoded, err := decode(contents)
	if err != nil {
		return nil, err
	}

	file := file{}
	err = json.Unmarshal(decoded, &file)
	if err != nil {
		return nil, err
	}

	resource, err := getResourceForToken(file, baseURI)
	if err != nil {
		return nil, err
	}

	config, err := adal.NewOAuthConfig(file.ActiveDirectoryEndpoint, file.TenantID)
	if err != nil {
		return nil, err
	}

	spToken, err := adal.NewServicePrincipalToken(*config, file.ClientID, file.ClientSecret, resource)
	if err != nil {
		return nil, err
	}

	return autorest.NewBearerAuthorizer(spToken), nil
}