Merge pull request 'fix: use numeric UID for USER directive (DL3066)' (#21) from fix/hadolint-DL3066-numeric-uid into master

Reviewed-on: #21

Dockerfile

@@ -3,7 +3,7 @@ LABEL maintainer="Cabillot Julien <dockerimages@cabillot.eu>"
 
 # hadolint ignore=DL3018
 RUN apk add --no-cache iperf3 && \
-    adduser -D iperf
+    adduser -D -u 1000 iperf
 
 ## Add Tini
 ENV "TINI_VERSION" "v0.16.1"
@@ -11,7 +11,7 @@ ENV "TINI_VERSION" "v0.16.1"
 #RUN chmod +x "/tini"
 #ENTRYPOINT ["/tini", "--"]
 
-USER "iperf"
+USER 1000
 
 # hadolint ignore=DL4004
 ENTRYPOINT [ "/usr/bin/iperf3" ]