builder: error out when no valid modules are specified

diff --git a/builder-support/dockerfiles/Dockerfile.target.sdist b/builder-support/dockerfiles/Dockerfile.target.sdist
index 81760329a7471d1853a7acd6e66cfe700a20e52f..57c09725c3e262858c36fbd0220dda780a757a0b 100644 (file)
--- a/builder-support/dockerfiles/Dockerfile.target.sdist
+++ b/builder-support/dockerfiles/Dockerfile.target.sdist
@@ -13,6 +13,10 @@
 FROM alpine:3.6 as sdist
 ARG BUILDER_CACHE_BUSTER=
 
+@IF [ -z "$M_all$M_authoritative$M_recursor$M_dnsdist"]
+RUN echo "no valid modules specified!" ; exit 1
+@ENDIF
+
 @IF [ ! -z "$M_authoritative$M_all" ]
 COPY --from=pdns-authoritative /sdist/ /sdist/
 @ENDIF