Utility methods to write and read local config file (#149)

Adds rudimentary support for writing/reading a local config file.

src/cli/cli.go

@@ -41,6 +41,7 @@ func initConfig() {
 
 		// Search config in home directory with name ".corso" (without extension).
 		viper.AddConfigPath(home)
+		viper.SetConfigType("toml")
 		viper.SetConfigName(".corso")
 	}
 

src/cli/config/config.go

@@ -0,0 +1,56 @@
+package config
+
+import (
+	"github.com/alcionai/corso/pkg/repository"
+	"github.com/alcionai/corso/pkg/storage"
+	"github.com/pkg/errors"
+	"github.com/spf13/viper"
+)
+
+const (
+	// S3 config
+	ProviderTypeKey = "provider"
+	BucketNameKey   = "bucket"
+	EndpointKey     = "endpoint"
+	PrefixKey       = "prefix"
+
+	// M365 config
+	TenantIDKey = "tenantid"
+)
+
+// WriteRepoConfig currently just persists corso config to the config file
+// It does not check for conflicts or existing data.
+func WriteRepoConfig(s3Config storage.S3Config, account repository.Account) error {
+	// Rudimentary support for persisting repo config
+	// TODO: Handle conflicts, support other config types
+	viper.Set(ProviderTypeKey, storage.ProviderS3.String())
+	viper.Set(BucketNameKey, s3Config.Bucket)
+	viper.Set(EndpointKey, s3Config.Endpoint)
+	viper.Set(PrefixKey, s3Config.Prefix)
+	viper.Set(TenantIDKey, account.TenantID)
+
+	if err := viper.SafeWriteConfig(); err != nil {
+		if _, ok := err.(viper.ConfigFileAlreadyExistsError); ok {
+			return viper.GetViper().WriteConfig()
+		}
+		return err
+	}
+	return nil
+}
+
+func ReadRepoConfig() (s3Config storage.S3Config, account repository.Account, err error) {
+	if err = viper.ReadInConfig(); err != nil {
+		return s3Config, account, errors.Wrap(err, "reading config file: "+viper.ConfigFileUsed())
+	}
+
+	if providerType := viper.GetString(ProviderTypeKey); providerType != storage.ProviderS3.String() {
+		return s3Config, account, errors.New("Unsupported storage provider: " + providerType)
+	}
+
+	s3Config.Bucket = viper.GetString(BucketNameKey)
+	s3Config.Endpoint = viper.GetString(EndpointKey)
+	s3Config.Prefix = viper.GetString(PrefixKey)
+	account.TenantID = viper.GetString(TenantIDKey)
+
+	return s3Config, account, nil
+}

src/cli/repo/s3.go

@@ -5,7 +5,9 @@ import (
 
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 
+	"github.com/alcionai/corso/cli/config"
 	"github.com/alcionai/corso/cli/utils"
 	"github.com/alcionai/corso/pkg/credentials"
 	"github.com/alcionai/corso/pkg/repository"
@@ -82,6 +84,10 @@ func initS3Cmd(cmd *cobra.Command, args []string) error {
 	defer utils.CloseRepo(cmd.Context(), r)
 
 	fmt.Printf("Initialized a S3 repository within bucket %s.\n", s3Cfg.Bucket)
+
+	if err = config.WriteRepoConfig(s3Cfg, a); err != nil {
+		return errors.Wrap(err, "Failed to write repository configuration")
+	}
 	return nil
 }
 
@@ -111,6 +117,14 @@ func connectS3Cmd(cmd *cobra.Command, args []string) error {
 		len(m365.ClientSecret) > 0,
 		len(s3Cfg.SecretKey) > 0)
 
+	// TODO: Merge/Validate any local configuration here to make sure there are no conflicts
+	// For now - just reading/logging the local config here (a successful repo connect will overwrite)
+	localS3Cfg, localAccount, err := config.ReadRepoConfig()
+	if err != nil {
+		return err
+	}
+	fmt.Printf("ConfigFile - %s\n\tbucket:\t%s\n\ttenantID:\t%s\n", viper.ConfigFileUsed(), localS3Cfg.Bucket, localAccount.TenantID)
+
 	a := repository.Account{
 		TenantID:     m365.TenantID,
 		ClientID:     m365.ClientID,
@@ -128,6 +142,10 @@ func connectS3Cmd(cmd *cobra.Command, args []string) error {
 	defer utils.CloseRepo(cmd.Context(), r)
 
 	fmt.Printf("Connected to S3 bucket %s.\n", s3Cfg.Bucket)
+
+	if err = config.WriteRepoConfig(s3Cfg, a); err != nil {
+		return errors.Wrap(err, "Failed to write repository configuration")
+	}
 	return nil
 }