GetStore modifications, Create GetLocalStorageConfig and SaveLocalSto…

…rageConfig

If passing either just a runroot or both a runroot and a graphroot
GetStore() was returning when finding a match for JUST the graph root,
overriding the runroot and using a different location than specified

Also create two new helper functions which add the ability to retrieve and overwrite
the toml config in the user's storage.conf file

Signed-off-by: cdoern <cdoern@redhat.com>

store.go

@@ -647,17 +647,23 @@ func GetStore(options types.StoreOptions) (Store, error) {
 	storesLock.Lock()
 	defer storesLock.Unlock()
 
+	// return if BOTH run and graph root are matched, otherwise our run-root can be overriden if the graph is found first
 	for _, s := range stores {
-		if s.graphRoot == options.GraphRoot && (options.GraphDriverName == "" || s.graphDriverName == options.GraphDriverName) {
+		if (s.graphRoot == options.GraphRoot) && (s.runRoot == options.RunRoot) && (options.GraphDriverName == "" || s.graphDriverName == options.GraphDriverName) {
 			return s, nil
 		}
 	}
 
-	if options.GraphRoot == "" {
-		return nil, errors.Wrap(ErrIncompleteOptions, "no storage root specified")
-	}
-	if options.RunRoot == "" {
-		return nil, errors.Wrap(ErrIncompleteOptions, "no storage runroot specified")
+	// if passed a run-root or graph-root alone, the other should be defaulted only error if we have neither.
+	switch {
+	case options.RunRoot != "" && options.GraphRoot != "":
+		break
+	case options.GraphRoot == "" && options.RunRoot != "":
+		options.GraphRoot = types.Options().GraphRoot
+	case options.RunRoot == "" && options.GraphRoot != "":
+		options.RunRoot = types.Options().RunRoot
+	default:
+		return nil, errors.Wrap(ErrIncompleteOptions, "no storage runroot or graphroot specified")
 	}
 
 	if err := os.MkdirAll(options.RunRoot, 0700); err != nil {

types/options.go

@@ -13,6 +13,7 @@ import (
 	"github.com/containers/storage/drivers/overlay"
 	cfg "github.com/containers/storage/pkg/config"
 	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/unshare"
 	"github.com/sirupsen/logrus"
 )
 
@@ -424,3 +425,40 @@ func ReloadConfigurationFile(configFile string, storeOptions *StoreOptions) {
 func Options() StoreOptions {
 	return defaultStoreOptions
 }
+
+// SaveLocalStorageConfig overwrites the tomlConfig in storage.conf with the given conf
+func SaveLocalStorageConfig(conf tomlConfig) error {
+	configFile, err := DefaultConfigFile(unshare.IsRootless())
+	if err != nil {
+		return err
+	}
+	if _, err := os.Stat(configFile); err == nil {
+		err = os.Remove(configFile)
+		if err != nil {
+			return err
+		}
+	}
+	f, err := os.Open(configFile)
+	if err != nil {
+		return err
+	}
+
+	return toml.NewEncoder(f).Encode(conf)
+}
+
+// GetLocalStorageConfig is used to retreive the storage.conf toml in order to overwrite it
+func GetLocalStorageConfig() (*tomlConfig, error) {
+	config := new(tomlConfig)
+
+	configFile, err := DefaultConfigFile(unshare.IsRootless())
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = toml.DecodeFile(configFile, &config)
+	if err != nil {
+		return nil, err
+	}
+
+	return config, nil
+}