Update build

Dockerfile

@@ -1,9 +1,11 @@
-FROM golang:1.16-alpine
-RUN apk add libcap git
-WORKDIR $GOPATH/src/git.k-space.ee/k-space/goredirect
+FROM golang:1.20 AS build
+WORKDIR /go/src/git.k-space.ee/k-space/goredirect
 COPY go.mod go.sum ./
 RUN go mod download
 COPY main.go .
-RUN go build -o goredirect main.go
-RUN setcap 'cap_net_bind_service=+ep' goredirect
-CMD ["./goredirect"]
+RUN go build -ldflags "-linkmode 'external' -extldflags '-static'" -o /go/server .
+
+FROM scratch
+WORKDIR /
+COPY --from=build /go/server /server
+CMD ["/server"]