play: Add basic Dockerfile for isolated Playground

play/Dockerfile

@@ -0,0 +1,17 @@
+FROM golang:1.13 AS builder
+WORKDIR /mnt
+
+COPY play/go.mod play/go.sum play/play.go /mnt/
+RUN go build -o play play.go
+
+FROM debian:stable-slim
+WORKDIR /play
+
+COPY --from=builder /mnt/play .
+COPY grawkit .
+COPY play/static static
+
+USER nobody
+EXPOSE 8080
+
+CMD ["/play/play", "-script-path", "grawkit", "-listen-address", ":8080"]