set repository config location w.r.t corso config location (#4638)

Create repository config(s) in the same parent directory as corso config instead of creating repository config in `/tmp` directory.
Scenarios:

1. CORSO_CONFIG_DIR set to /test/directory, --config-file not provided
    - `.corso.toml` should be created at /test/directory
    - `repository.config` should be created at /test/directory
2. CORSO_CONFIG_DIR not set, --config-file provided /test/directory-2
    - `.corso.toml` should be created at /test/directory-2
    - `repository.config` should be created at /test/directory-2
3. CORSO_CONFIG_DIR not set, --config-file not provided
    - `.corso.toml` should be created at /home/user
    - `repository.config` should be created at /home/user

#### Does this PR need a docs update or release note?

- [ ] ✅ Yes, it's included
- [x] 🕐 Yes, but in a later PR
- [ ] ⛔ No

#### Type of change

<!--- Please check the type of change your PR introduces: --->
- [ ] 🌻 Feature
- [x] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup

#### Issue(s)

* #4443 

#### Test Plan

<!-- How will this be tested prior to merging.-->
- [x] 💪 Manual
- [x] ⚡ Unit test
- [x] 💚 E2E

src/cli/config/config.go

@@ -2,6 +2,8 @@ package config
 
 import (
 	"context"
+	"errors"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"slices"
@@ -73,8 +75,8 @@ func init() {
 
 // adds the persistent flag --config-file to the provided command.
 func AddConfigFlags(cmd *cobra.Command) {
-	fs := cmd.PersistentFlags()
-	fs.StringVar(
+	pf := cmd.PersistentFlags()
+	pf.StringVar(
 		&configFilePathFlag,
 		"config-file", displayDefaultFP, "config file location")
 }
@@ -86,17 +88,22 @@ func AddConfigFlags(cmd *cobra.Command) {
 // InitFunc provides a func that lazily initializes viper and
 // verifies that the configuration was able to read a file.
 func InitFunc(cmd *cobra.Command, args []string) error {
+	ctx := cmd.Context()
+
 	fp := configFilePathFlag
 	if len(fp) == 0 || fp == displayDefaultFP {
 		fp = configFilePath
 	}
 
-	err := initWithViper(GetViper(cmd.Context()), fp)
-	if err != nil {
+	vpr := GetViper(ctx)
+
+	if err := initWithViper(vpr, fp); err != nil {
 		return err
 	}
 
-	return Read(cmd.Context())
+	ctx = SetViper(ctx, vpr)
+
+	return Read(ctx)
 }
 
 // initWithViper implements InitConfig, but takes in a viper
@@ -114,26 +121,23 @@ func initWithViper(vpr *viper.Viper, configFP string) error {
 		vpr.AddConfigPath(configDir)
 		vpr.SetConfigType("toml")
 		vpr.SetConfigName(".corso")
+	} else {
+		ext := filepath.Ext(configFP)
+		if len(ext) == 0 {
+			return clues.New("config file requires an extension e.g. `toml`")
+		}
 
-		return nil
+		fileName := filepath.Base(configFP)
+		fileName = strings.TrimSuffix(fileName, ext)
+		vpr.SetConfigType(strings.TrimPrefix(ext, "."))
+		vpr.SetConfigName(fileName)
+		vpr.SetConfigFile(configFP)
+		// We also configure the path, type and filename
+		// because `vpr.SafeWriteConfig` needs these set to
+		// work correctly (it does not use the configured file)
+		vpr.AddConfigPath(filepath.Dir(configFP))
 	}
 
-	vpr.SetConfigFile(configFP)
-	// We also configure the path, type and filename
-	// because `vpr.SafeWriteConfig` needs these set to
-	// work correctly (it does not use the configured file)
-	vpr.AddConfigPath(filepath.Dir(configFP))
-
-	ext := filepath.Ext(configFP)
-	if len(ext) == 0 {
-		return clues.New("config file requires an extension e.g. `toml`")
-	}
-
-	fileName := filepath.Base(configFP)
-	fileName = strings.TrimSuffix(fileName, ext)
-	vpr.SetConfigType(strings.TrimPrefix(ext, "."))
-	vpr.SetConfigName(fileName)
-
 	return nil
 }
 
@@ -282,7 +286,10 @@ func getStorageAndAccountWithViper(
 	// possibly read the prior config from a .corso file
 	if readFromFile {
 		if err := vpr.ReadInConfig(); err != nil {
-			if _, ok := err.(viper.ConfigFileNotFoundError); !ok {
+			configNotSet := errors.As(err, &viper.ConfigFileNotFoundError{})
+			configNotFound := errors.Is(err, fs.ErrNotExist)
+
+			if !configNotSet && !configNotFound {
 				return config, clues.Wrap(err, "reading corso config file: "+vpr.ConfigFileUsed())
 			}
 

src/cli/config/storage.go

@@ -45,15 +45,17 @@ func configureStorage(
 		return store, clues.Wrap(err, "validating corso credentials")
 	}
 
+	configDir, _ := filepath.Split(vpr.ConfigFileUsed())
+
 	cCfg := storage.CommonConfig{
-		Corso: corso,
+		Corso:       corso,
+		KopiaCfgDir: configDir,
 	}
 	// the following is a hack purely for integration testing.
 	// the value is not required, and if empty, kopia will default
 	// to its routine behavior
 	if t, ok := vpr.Get("corso-testing").(bool); t && ok {
-		dir, _ := filepath.Split(vpr.ConfigFileUsed())
-		cCfg.KopiaCfgDir = dir
+		cCfg.KopiaCfgDir = configDir
 	}
 
 	// ensure required properties are present