Merge branch 'feature/multistage-build-9.20' into 'v9.20'

Multistage build 9.20

See merge request isc-projects/bind9-docker!1

Dockerfile

@@ -7,8 +7,8 @@ ENV LC_ALL=C.UTF-8
 ARG UID=53
 ARG GID=53
 
-ARG BIND9_VERSION=9.18.35
-ARG BIND9_CHECKSUM=1bf332a8c056d92b87ffde518747f0b7ffd3e48be7ecaa43fa37fca131c52020
+ARG BIND9_VERSION=9.21.6
+ARG BIND9_CHECKSUM=ff9722bdb353df442ca95444148aa23e3d16153e4576d2bdaa008fa7f37e019c
 
 RUN apk --no-cache update
 RUN apk --no-cache upgrade
@@ -53,7 +53,9 @@ RUN apk --no-cache add \
         procps \
 	protobuf-c \
         protobuf-c-dev \
-        tzdata
+        tzdata \
+        userspace-rcu \
+        userspace-rcu-dev
 
 RUN mkdir -p /usr/src
 ADD https://downloads.isc.org/isc/bind9/${BIND9_VERSION}/bind-${BIND9_VERSION}.tar.xz /usr/src
@@ -94,7 +96,8 @@ RUN apk --no-cache add \
         nghttp2-libs \
         procps \
         protobuf-c \
-        tzdata
+        tzdata \
+        userspace-rcu
 
 # Copy binaries from previous stage
 COPY --from=builder /dist/ /