keeper: validate id against postgres repl slot name rules.

cmd/keeper/keeper.go

@@ -72,7 +72,7 @@ type config struct {
 var cfg config
 
 func init() {
-	cmdKeeper.PersistentFlags().StringVar(&cfg.id, "id", "", "keeper id (must be unique in the cluster)")
+	cmdKeeper.PersistentFlags().StringVar(&cfg.id, "id", "", "keeper id (must be unique in the cluster and can contain only lower-case letters, numbers and the underscore character). If not provided a random id will be generated.")
 	cmdKeeper.PersistentFlags().StringVar(&cfg.etcdEndpoints, "etcd-endpoints", common.DefaultEtcdEndpoints, "a comma-delimited list of etcd endpoints")
 	cmdKeeper.PersistentFlags().StringVar(&cfg.dataDir, "data-dir", "", "data directory")
 	cmdKeeper.PersistentFlags().StringVar(&cfg.clusterName, "cluster-name", "", "cluster name")
@@ -701,6 +701,11 @@ func keeper(cmd *cobra.Command, args []string) {
 		log.Fatalf("cannot take exclusive lock on data dir %q: %v", cfg.dataDir, err)
 	}
 
+	if cfg.id != "" {
+		if !pg.IsValidReplSlotName(cfg.id) {
+			log.Fatalf("keeper id %q not valid. It can contain only lower-case letters, numbers and the underscore character", cfg.id)
+		}
+	}
 	id, err := getIDFromFile(cfg)
 	if err != nil {
 		log.Fatalf("error: %v", err)
@@ -716,11 +721,11 @@ func keeper(cmd *cobra.Command, args []string) {
 				u := uuid.NewV4()
 				id = fmt.Sprintf("%x", u[:4])
 			}
+			log.Infof("generated id: %s", id)
 		}
 		if err := saveIDToFile(cfg, id); err != nil {
 			log.Fatalf("error: %v", err)
 		}
-		log.Infof("generated id: %s", id)
 	}
 
 	log.Infof("id: %s", id)

pkg/postgresql/utils.go

@@ -30,6 +30,10 @@ import (
 	"github.com/sorintlab/stolon/Godeps/_workspace/src/golang.org/x/net/context"
 )
 
+var (
+	ValidReplSlotName = regexp.MustCompile("^[a-z0-9_]+$")
+)
+
 func Exec(ctx context.Context, db *sql.DB, query string, args ...interface{}) (sql.Result, error) {
 	ch := make(chan struct {
 		res sql.Result
@@ -249,3 +253,7 @@ func GetTimelinesHistory(ctx context.Context, timeline uint64, replConnString st
 	}
 	return nil, fmt.Errorf("query returned 0 rows")
 }
+
+func IsValidReplSlotName(name string) bool {
+	return ValidReplSlotName.MatchString(name)
+}

pkg/postgresql/utils_test.go

@@ -66,3 +66,26 @@ func TestParseTimeLineHistory(t *testing.T) {
 	}
 
 }
+
+func TestValidReplSlotName(t *testing.T) {
+	tests := []struct {
+		name  string
+		valid bool
+	}{
+		{"aaaaaaaa", true},
+		{"a12345aa", true},
+		{"_a1_2345aa_", true},
+		{"", false},
+		{"a-aaaaaaa", false},
+		{"_a1_-2345aa_", false},
+		{"ABC123", false},
+		{"$123", false},
+	}
+
+	for i, tt := range tests {
+		valid := IsValidReplSlotName(tt.name)
+		if valid != tt.valid {
+			t.Errorf("%d: replication slot name %q got valid: %t but wanted valid: %t", i, tt.name, valid, tt.valid)
+		}
+	}
+}