update Dockerfile to use Go 1.24 and Alpine 3.21

- `slog` package requires Go 1.18+
- fix `AS` casing
- fix `CMD` syntax

Author: panz3r

Dockerfile

@@ -1,12 +1,13 @@
-FROM golang:1.18.2-alpine3.16 as builder
+FROM golang:1.24-alpine3.21 AS builder
 
 WORKDIR /code/
 
 ADD src/ .
 
 RUN go build -o dist/ -ldflags "-s -w"
 
-FROM alpine:3.16
+FROM alpine:3.21
+
 WORKDIR /code/
 
 COPY docker-entrypoint.sh /bin/
@@ -15,4 +16,4 @@ ENTRYPOINT ["/bin/docker-entrypoint.sh"]
 COPY --from=builder /code/dist/go-http-server /bin/
 RUN chmod +x /bin/go-http-server
 
-CMD "/bin/go-http-server"
+CMD ["/bin/go-http-server"]