try pulling in pre built binaries (#321)

cmd/otelcontribcol/Dockerfile

@@ -1,10 +1,3 @@
-FROM golang:1.20 AS build
-
-WORKDIR /src
-ADD . /src
-
-RUN cd cmd/otelcontribcol && CGO_ENABLED=0 go build -o /otelcontribcol
-
 FROM alpine:latest as prep
 RUN apk --update add ca-certificates
 
@@ -15,8 +8,11 @@ FROM scratch
 ARG USER_UID=10001
 USER ${USER_UID}
 
+ARG TARGETOS
+ARG TARGETARCH
+
 COPY --from=prep /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
-COPY --from=build /otelcontribcol /otelcontribcol
+COPY ../../bin/otelcontribcol_${TARGETOS}_${TARGETARCH} /otelcontribcol
 EXPOSE 4317 55680 55679
 ENTRYPOINT ["/otelcontribcol"]
 CMD ["--config", "/etc/otel/config.yaml"]