Ensure default directory path to db file exists (#140)

fixes #122

README.md

@@ -113,6 +113,20 @@ For example, to disable search attribute cache to make created search attributes
 temporalite start --dynamic-config-value system.forceSearchAttributesCacheRefreshOnRead=true
 ```
 
+## Development
+
+To compile the source run:
+
+```bash
+go build -o dist/temporalite ./cmd/temporalite 
+```
+
+To run all tests:
+
+```bash
+go test ./...
+```
+
 ## Known Issues
 
 - When consuming Temporalite as a library in go mod, you may want to replace grpc-gateway with a fork to address URL escaping issue in UI. See <https://github.com/temporalio/temporalite/pull/118>

cmd/temporalite/main.go

@@ -10,6 +10,7 @@ import (
 	goLog "log"
 	"net"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/urfave/cli/v2"
@@ -168,6 +169,13 @@ func buildCLI() *cli.App {
 					return cli.Exit(fmt.Sprintf("ERROR: only one of %q or %q flags may be passed at a time", ephemeralFlag, dbPathFlag), 1)
 				}
 
+				// Make sure the default db path exists (user does not specify path explicitly)
+				if !c.IsSet(dbPathFlag) {
+					if err := os.MkdirAll(filepath.Dir(c.String(dbPathFlag)), os.ModePerm); err != nil {
+						return cli.Exit(err.Error(), 1)
+					}
+				}
+
 				switch c.String(logFormatFlag) {
 				case "json", "pretty":
 				default: