Use modified knockd to set a cooldown on port 19132 (#2003)

build/alpine/install-packages.sh

@@ -21,7 +21,7 @@ apk add --no-cache -U \
     rsync \
     nano \
     sudo \
-    knock \
     tar \
     zstd \
-    nfs-utils
+    nfs-utils \
+    libpcap

build/ol/install-packages.sh

@@ -33,6 +33,6 @@ dnf install -y ImageMagick \
   unzip \
   zstd \
   lbzip2 \
-  knock
+  libpcap
 
 bash /build/ol/install-gosu.sh

build/ubuntu/install-packages.sh

@@ -23,7 +23,7 @@ apt-get install -y \
   unzip \
   zstd \
   lbzip2 \
-  knockd \
-  nfs-common
+  nfs-common \
+  libpcap0.8
 
-apt-get clean
+apt-get clean