utils: split generation and writing of storage.conf

split the generation for the default storage.conf and when we write it
if not existing for a rootless user.

This is necessary because during the startup we might be overriding
the default configuration through --storage-driver and --storage-opt,
that would not be written down to the storage.conf file we generated.

Closes: https://github.com/containers/libpod/issues/2659

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

2 files changed, 46 insertions, 35 deletions

diff --git a/libpod/runtime.go b/libpod/runtime.go
index f7ca6b135..b3b75d791 100644
--- a/libpod/runtime.go
+++ b/libpod/runtime.go
@@ -505,17 +505,27 @@ func newRuntimeFromConfig(userConfigPath string, options ...RuntimeOption) (runt
 			return nil, errors.Wrapf(err, "error configuring runtime")
 		}
 	}
-	if !foundConfig && rootlessConfigPath != "" {
-		os.MkdirAll(filepath.Dir(rootlessConfigPath), 0755)
-		file, err := os.OpenFile(rootlessConfigPath, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0666)
-		if err != nil && !os.IsExist(err) {
-			return nil, errors.Wrapf(err, "cannot open file %s", rootlessConfigPath)
+	if rootlessConfigPath != "" {
+		// storage.conf
+		storageConfFile := util.StorageConfigFile()
+		if _, err := os.Stat(storageConfFile); os.IsNotExist(err) {
+			if err := util.WriteStorageConfigFile(&runtime.config.StorageConfig, storageConfFile); err != nil {
+				return nil, errors.Wrapf(err, "cannot write config file %s", storageConfFile)
+			}
 		}
-		if err == nil {
-			defer file.Close()
-			enc := toml.NewEncoder(file)
-			if err := enc.Encode(runtime.config); err != nil {
-				os.Remove(rootlessConfigPath)
+
+		if !foundConfig {
+			os.MkdirAll(filepath.Dir(rootlessConfigPath), 0755)
+			file, err := os.OpenFile(rootlessConfigPath, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0666)
+			if err != nil && !os.IsExist(err) {
+				return nil, errors.Wrapf(err, "cannot open file %s", rootlessConfigPath)
+			}
+			if err == nil {
+				defer file.Close()
+				enc := toml.NewEncoder(file)
+				if err := enc.Encode(runtime.config); err != nil {
+					os.Remove(rootlessConfigPath)
+				}
 			}
 		}
 	}
diff --git a/pkg/util/utils.go b/pkg/util/utils.go
index 8562afab1..a408ad34b 100644
--- a/pkg/util/utils.go
+++ b/pkg/util/utils.go
@@ -311,36 +311,37 @@ func GetDefaultStoreOptions() (storage.StoreOptions, error) {
 		storageOpts = storage.StoreOptions{}
 		storage.ReloadConfigurationFile(storageConf, &storageOpts)
 	}
-
-	if rootless.IsRootless() {
-		if os.IsNotExist(err) {
-			os.MkdirAll(filepath.Dir(storageConf), 0755)
-			file, err := os.OpenFile(storageConf, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0666)
-			if err != nil {
-				return storageOpts, errors.Wrapf(err, "cannot open %s", storageConf)
-			}
-
-			tomlConfiguration := getTomlStorage(&storageOpts)
-			defer file.Close()
-			enc := toml.NewEncoder(file)
-			if err := enc.Encode(tomlConfiguration); err != nil {
-				os.Remove(storageConf)
-			}
-		} else if err == nil {
-			// If the file did not specify a graphroot or runroot,
-			// set sane defaults so we don't try and use root-owned
-			// directories
-			if storageOpts.RunRoot == "" {
-				storageOpts.RunRoot = defaultRootlessRunRoot
-			}
-			if storageOpts.GraphRoot == "" {
-				storageOpts.GraphRoot = defaultRootlessGraphRoot
-			}
+	if rootless.IsRootless() && err == nil {
+		// If the file did not specify a graphroot or runroot,
+		// set sane defaults so we don't try and use root-owned
+		// directories
+		if storageOpts.RunRoot == "" {
+			storageOpts.RunRoot = defaultRootlessRunRoot
+		}
+		if storageOpts.GraphRoot == "" {
+			storageOpts.GraphRoot = defaultRootlessGraphRoot
 		}
 	}
 	return storageOpts, nil
 }
 
+// WriteStorageConfigFile writes the configuration to a file
+func WriteStorageConfigFile(storageOpts *storage.StoreOptions, storageConf string) error {
+	os.MkdirAll(filepath.Dir(storageConf), 0755)
+	file, err := os.OpenFile(storageConf, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0666)
+	if err != nil {
+		return errors.Wrapf(err, "cannot open %s", storageConf)
+	}
+	tomlConfiguration := getTomlStorage(storageOpts)
+	defer file.Close()
+	enc := toml.NewEncoder(file)
+	if err := enc.Encode(tomlConfiguration); err != nil {
+		os.Remove(storageConf)
+		return err
+	}
+	return nil
+}
+
 // StorageConfigFile returns the path to the storage config file used
 func StorageConfigFile() string {
 	if rootless.IsRootless() {