Move to non-root container

Author: alex1989hu

build/Dockerfile

@@ -9,6 +9,9 @@ COPY collector ./collector
 COPY client ./client
 RUN GO111MODULE=on CGO_ENABLED=0 GOOS=linux go build -mod=vendor -a -installsuffix cgo -ldflags "-X main.version=${VERSION} -X main.gitCommit=${GIT_COMMIT}" -o exporter .
 
-FROM alpine:3.11
+FROM gcr.io/distroless/static:latest
 COPY --from=builder /go/src/github.com/nginxinc/nginx-prometheus-exporter/exporter /usr/bin/
+
+USER 1001:1001
+
 ENTRYPOINT [ "/usr/bin/exporter" ]