Remove SSH host keys after installing the custom version of sshd

build_debian.sh

@@ -407,7 +407,8 @@ sudo sed -i 's/LOAD_KEXEC=true/LOAD_KEXEC=false/' $FILESYSTEM_ROOT/etc/default/k
 ## Remove sshd host keys, and will regenerate on first sshd start
 sudo rm -f $FILESYSTEM_ROOT/etc/ssh/ssh_host_*_key*
 sudo cp files/sshd/host-ssh-keygen.sh $FILESYSTEM_ROOT/usr/local/bin/
-sudo cp -f files/sshd/sshd.service $FILESYSTEM_ROOT/lib/systemd/system/ssh.service
+sudo mkdir $FILESYSTEM_ROOT/etc/systemd/system/ssh.service.d
+sudo cp files/sshd/override.conf $FILESYSTEM_ROOT/etc/systemd/system/ssh.service.d/override.conf
 # Config sshd
 # 1. Set 'UseDNS' to 'no'
 # 2. Configure sshd to close all SSH connetions after 15 minutes of inactivity

files/build_templates/sonic_debian_extension.j2

@@ -329,6 +329,11 @@ sudo LANG=C DEBIAN_FRONTEND=noninteractive chroot $FILESYSTEM_ROOT apt-get -y in
 # Install custom-built openssh sshd
 sudo dpkg --root=$FILESYSTEM_ROOT -i $debs_path/openssh-server_*.deb
 
+# Remove sshd host keys, and will regenerate on first sshd start. This needs to be
+# done again here because our custom version of sshd is being installed, which
+# will regenerate the sshd host keys.
+sudo rm -f $FILESYSTEM_ROOT/etc/ssh/ssh_host_*_key*
+
 {% if sonic_asic_platform == 'broadcom' %}
 # Install custom-built flashrom
 sudo dpkg --root=$FILESYSTEM_ROOT -i $debs_path/flashrom_*.deb

files/sshd/override.conf

@@ -0,0 +1,4 @@
+[Service]
+ExecStartPre=
+ExecStartPre=/usr/local/bin/host-ssh-keygen.sh
+ExecStartPre=/usr/sbin/sshd -t