Revert to busybox nc for metricsproxy

nmap-ncat is causing issues in metricsproxy with globalnet:

Ncat: Version 7.92 ( https://nmap.org/ncat )
Ncat: Listening on :::8081
Ncat: Listening on 0.0.0.0:8081
Ncat: Connection from 10.129.0.19.
Ncat: Connection from 10.129.0.19:45064.
Ncat: assertion failed: count <= INT_MAX QUITTING.

It's not clear how to fix that, so this installs busybox and reverts
to busybox nc instead. To avoid having too many changes in nettest,
nmap-ncat is preserved for other uses.

Signed-off-by: Stephen Kitt <[email protected]>

Author: skitt

package/Dockerfile.nettest

@@ -9,7 +9,7 @@ COPY scripts/shared/dnf_install /
 
 RUN /dnf_install -a ${TARGETPLATFORM} -v ${FEDORA_VERSION} -r /output/nettest \
     glibc bash glibc-minimal-langpack coreutils-single libcurl-minimal \
-    bind-utils curl-minimal iperf3 iproute iputils netperf nmap-ncat tcpdump
+    bind-utils busybox curl-minimal iperf3 iproute iputils netperf nmap-ncat tcpdump
 
 FROM scratch
 ARG TARGETPLATFORM

scripts/nettest/metricsproxy

@@ -1,4 +1,4 @@
 #!/bin/sh
 
 # Arguments: source-port target-IP target-port
-exec /usr/bin/ncat -v -lk -p "$1" -c "/usr/bin/ncat $2 $3"
+exec /usr/sbin/busybox nc -v -lk -p "$1" -e /usr/sbin/busybox nc "$2" "$3"