Add version flag (#12)

Dockerfile

@@ -1,10 +1,14 @@
 FROM golang:1.23-bookworm AS go
 WORKDIR /src
+ARG VERSION=DEV
 ADD go.mod go.sum /src/
 RUN go mod download
 ADD . /src
 RUN mkdir -p /workspace
-RUN go build -o /src/jimmy github.com/silas/jimmy
+RUN go build \
+  -ldflags="-X 'github.com/silas/jimmy/internal/constants.Version=${VERSION}'" \
+  -o /src/jimmy \
+  github.com/silas/jimmy
 
 FROM gcr.io/distroless/base-debian12
 COPY --from=go /workspace /src/jimmy /

README.md

@@ -23,4 +23,5 @@ Flags:
   -h, --help              help for jimmy
   -i, --instance string   set Spanner instance ID
   -p, --project string    set Google project ID
+  -v, --version           version for jimmy
 ```

internal/cmd/cmd.go

@@ -19,6 +19,7 @@ func New() *cobra.Command {
 
 	cmd := &cobra.Command{
 		Use:           constants.AppName,
+		Version:       constants.Version,
 		SilenceUsage:  false,
 		SilenceErrors: true,
 	}

internal/constants/build.go

@@ -0,0 +1,5 @@
+package constants
+
+var (
+	Version = "DEV"
+)