FROM golang:1.23-alpine AS builder
WORKDIR /app
COPY go.mod go.sum* ./
RUN go mod download
COPY main.go .
RUN go mod tidy && CGO_ENABLED=0 GOOS=linux go build -o resolver .

FROM alpine:latest
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=builder /app/resolver .
EXPOSE 2020
CMD ["./resolver"]