cmd: Allows reading database from env in migrate sql

cmd/cli/handler_migrate.go

@@ -36,6 +36,7 @@ import (
 	"github.com/ory/hydra/pkg"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 )
 
 type MigrateHandler struct {
@@ -78,12 +79,24 @@ func (h *MigrateHandler) connectToSql(dsn string) (*sqlx.DB, error) {
 }
 
 func (h *MigrateHandler) MigrateSQL(cmd *cobra.Command, args []string) {
-	if len(args) == 0 {
-		fmt.Println(cmd.UsageString())
-		return
+	var dburl string
+	if readFromEnv, _ := cmd.Flags().GetBool("read-from-env"); readFromEnv {
+		if len(viper.GetString("DATABASE_URL")) == 0 {
+			fmt.Println(cmd.UsageString())
+			fmt.Println("")
+			fmt.Println("When using flag -e, environment variable DATABASE_URL must be set")
+			return
+		}
+		dburl = viper.GetString("DATABASE_URL")
+	} else {
+		if len(args) != 1 {
+			fmt.Println(cmd.UsageString())
+			return
+		}
+		dburl = args[0]
 	}
 
-	db, err := h.connectToSql(args[0])
+	db, err := h.connectToSql(dburl)
 	if err != nil {
 		fmt.Printf("An error occurred while connecting to SQL: %s", err)
 		os.Exit(1)

cmd/migrate_sql.go

@@ -32,6 +32,10 @@ upgrading Hydra 0.7.0 to 0.8.0 requires running this command.
 It is recommended to run this command close to the SQL instance (e.g. same subnet) instead of over the public internet.
 This decreases risk of failure and decreases time required.
 
+You can read in the database URL using the -e flag, for example:
+	export DATABASE_URL=...
+	hydra migrate sql -e
+
 ### WARNING ###
 
 Before running this command on an existing database, create a back up!
@@ -41,4 +45,6 @@ Before running this command on an existing database, create a back up!
 
 func init() {
 	migrateCmd.AddCommand(migrateSqlCmd)
+
+	migrateSqlCmd.Flags().BoolP("read-from-env", "e", false, "If set, reads the database URL from the environment variable DATABASE_URL.")
 }

docker-compose.yml

@@ -20,8 +20,11 @@ services:
       dockerfile: Dockerfile
     links:
       - postgresd:postgresd
+    environment:
+#      - LOG_LEVEL=debug
+      - DATABASE_URL=postgres://hydra:secret@postgresd:5432/hydra?sslmode=disable
     command:
-      migrate sql postgres://hydra:secret@postgresd:5432/hydra?sslmode=disable
+      migrate sql -e
     restart: on-failure
 
   hydra: