Remove ca-certificates, add EXPOSE to Dockerfile

Dockerfile

@@ -1,5 +1,4 @@
 FROM golang:alpine AS builder
-RUN apk add -U --no-cache ca-certificates && update-ca-certificates
 
 ENV GO111MODULE=on\
     CGO_ENABLED=0\
@@ -17,11 +16,11 @@ RUN go build -o main .
 WORKDIR /dist
 RUN cp /build/main .
 FROM scratch
-COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 COPY --from=builder /dist/main .
 
 COPY --from=builder /usr/local/go/lib/time/zoneinfo.zip /
 ENV ZONEINFO=/zoneinfo.zip
 ENV TZ=Asia/Seoul
 
+EXPOSE 4317
 ENTRYPOINT [ "./main", "run" ]