Add ability to retrieve runtime configuration from DB

When we create a Libpod database, we store a number of runtime
configuration fields in it. If we can retrieve those, we can use
them to configure the runtime to match the DB instead of inbuilt
defaults, helping to ensure that we don't error in cases where
our compiled-in defaults changed.

Signed-off-by: Matthew Heon <mheon@redhat.com>

1 files changed, 24 insertions, 19 deletions

diff --git a/libpod/boltdb_state_internal.go b/libpod/boltdb_state_internal.go
index cc7d106cc..8b7c3ae60 100644
--- a/libpod/boltdb_state_internal.go
+++ b/libpod/boltdb_state_internal.go
@@ -30,6 +30,13 @@ const (
 	containersName   = "containers"
 	podIDName        = "pod-id"
 	namespaceName    = "namespace"
+
+	staticDirName   = "static-dir"
+	tmpDirName      = "tmp-dir"
+	runRootName     = "run-root"
+	graphRootName   = "graph-root"
+	graphDriverName = "graph-driver-name"
+	osName          = "os"
 )
 
 var (
@@ -49,21 +56,19 @@ var (
 	containersBkt   = []byte(containersName)
 	podIDKey        = []byte(podIDName)
 	namespaceKey    = []byte(namespaceName)
+
+	staticDirKey   = []byte(staticDirName)
+	tmpDirKey      = []byte(tmpDirName)
+	runRootKey     = []byte(runRootName)
+	graphRootKey   = []byte(graphRootName)
+	graphDriverKey = []byte(graphDriverName)
+	osKey          = []byte(osName)
 )
 
 // Check if the configuration of the database is compatible with the
 // configuration of the runtime opening it
 // If there is no runtime configuration loaded, load our own
 func checkRuntimeConfig(db *bolt.DB, rt *Runtime) error {
-	var (
-		staticDir       = []byte("static-dir")
-		tmpDir          = []byte("tmp-dir")
-		runRoot         = []byte("run-root")
-		graphRoot       = []byte("graph-root")
-		graphDriverName = []byte("graph-driver-name")
-		osKey           = []byte("os")
-	)
-
 	err := db.Update(func(tx *bolt.Tx) error {
 		configBkt, err := getRuntimeConfigBucket(tx)
 		if err != nil {
@@ -74,31 +79,31 @@ func checkRuntimeConfig(db *bolt.DB, rt *Runtime) error {
 			return err
 		}
 
-		if err := validateDBAgainstConfig(configBkt, "static dir",
-			rt.config.StaticDir, staticDir, ""); err != nil {
+		if err := validateDBAgainstConfig(configBkt, "libpod root directory",
+			rt.config.StaticDir, staticDirKey, ""); err != nil {
 			return err
 		}
 
-		if err := validateDBAgainstConfig(configBkt, "tmp dir",
-			rt.config.TmpDir, tmpDir, ""); err != nil {
+		if err := validateDBAgainstConfig(configBkt, "libpod temporary files directory",
+			rt.config.TmpDir, tmpDirKey, ""); err != nil {
 			return err
 		}
 
-		if err := validateDBAgainstConfig(configBkt, "run root",
-			rt.config.StorageConfig.RunRoot, runRoot,
+		if err := validateDBAgainstConfig(configBkt, "storage temporary directory",
+			rt.config.StorageConfig.RunRoot, runRootKey,
 			storage.DefaultStoreOptions.RunRoot); err != nil {
 			return err
 		}
 
-		if err := validateDBAgainstConfig(configBkt, "graph root",
-			rt.config.StorageConfig.GraphRoot, graphRoot,
+		if err := validateDBAgainstConfig(configBkt, "storage graph root directory",
+			rt.config.StorageConfig.GraphRoot, graphRootKey,
 			storage.DefaultStoreOptions.GraphRoot); err != nil {
 			return err
 		}
 
-		return validateDBAgainstConfig(configBkt, "graph driver name",
+		return validateDBAgainstConfig(configBkt, "storage graph driver",
 			rt.config.StorageConfig.GraphDriverName,
-			graphDriverName,
+			graphDriverKey,
 			storage.DefaultStoreOptions.GraphDriverName)
 	})