FROM golang:1.21 as build

# Set destination for COPY
WORKDIR /app

# Download Go modules
COPY go.mod go.sum ./
RUN go mod download

# Copy the source code. Note the slash at the end, as explained in
# https://docs.docker.com/engine/reference/builder/#copy
COPY . ./

# Build
RUN CGO_ENABLED=0 GOOS=linux go build -o /listy

FROM alpine

COPY --from=build /listy /listy

# Optional:
# To bind to a TCP port, runtime parameters must be supplied to the docker command.
# But we can document in the Dockerfile what ports
# the application is going to listen on by default.
# https://docs.docker.com/engine/reference/builder/#expose
EXPOSE 5001

# Run
CMD ["/listy"]