Set hostname for mesh install

src/freedombone

   if grep -Fxq "set_your_domain_name" $COMPLETION_FILE; then
       return
   fi
+
+  echo "$DEFAULT_DOMAIN_NAME" > /etc/hostname
+  hostname $DEFAULT_DOMAIN_NAME
+
   if [[ $SYSTEM_TYPE == "$VARIANT_MESH" ]]; then
       return
   fi
 
-  echo "$DEFAULT_DOMAIN_NAME" > /etc/hostname
-  hostname $DEFAULT_DOMAIN_NAME
   if grep -q "127.0.1.1" /etc/hosts; then
       sed -i "s/127.0.1.1.*/127.0.1.1       $DEFAULT_DOMAIN_NAME/g" /etc/hosts
   else
   sed -i "s/#net.ipv4.conf.all.rp_filter=1/net.ipv4.conf.all.rp_filter=1/g" /etc/sysctl.conf
   sed -i "s/#net.ipv4.ip_forward=1/net.ipv4.ip_forward=0/g" /etc/sysctl.conf
   sed -i "s/#net.ipv6.conf.all.forwarding=1/net.ipv6.conf.all.forwarding=0/g" /etc/sysctl.conf
-  echo '# ignore pings' >> /etc/sysctl.conf
-  echo 'net.ipv4.icmp_echo_ignore_all = 1' >> /etc/sysctl.conf
-  echo 'net.ipv6.icmp_echo_ignore_all = 1' >> /etc/sysctl.conf
-  echo '# disable ipv6' >> /etc/sysctl.conf
-  echo 'net.ipv6.conf.all.disable_ipv6 = 1' >> /etc/sysctl.conf
-  echo 'net.ipv4.tcp_synack_retries = 2' >> /etc/sysctl.conf
-  echo 'net.ipv4.tcp_syn_retries = 1' >> /etc/sysctl.conf
-  echo '# keepalive' >> /etc/sysctl.conf
-  echo 'net.ipv4.tcp_keepalive_probes = 9' >> /etc/sysctl.conf
-  echo 'net.ipv4.tcp_keepalive_intvl = 75' >> /etc/sysctl.conf
-  echo 'net.ipv4.tcp_keepalive_time = 7200' >> /etc/sysctl.conf
+  if ! grep -q "ignore pings" /etc/sysctl.conf; then
+      echo '# ignore pings' >> /etc/sysctl.conf
+      echo 'net.ipv4.icmp_echo_ignore_all = 1' >> /etc/sysctl.conf
+      echo 'net.ipv6.icmp_echo_ignore_all = 1' >> /etc/sysctl.conf
+  fi
+  if ! grep -q "disable ipv6" /etc/sysctl.conf; then
+      echo '# disable ipv6' >> /etc/sysctl.conf
+      echo 'net.ipv6.conf.all.disable_ipv6 = 1' >> /etc/sysctl.conf
+  fi
+  if ! grep -q "net.ipv4.tcp_synack_retries" /etc/sysctl.conf; then
+      echo 'net.ipv4.tcp_synack_retries = 2' >> /etc/sysctl.conf
+      echo 'net.ipv4.tcp_syn_retries = 1' >> /etc/sysctl.conf
+  fi
+  if ! grep -q "keepalive" /etc/sysctl.conf; then
+      echo '# keepalive' >> /etc/sysctl.conf
+      echo 'net.ipv4.tcp_keepalive_probes = 9' >> /etc/sysctl.conf
+      echo 'net.ipv4.tcp_keepalive_intvl = 75' >> /etc/sysctl.conf
+      echo 'net.ipv4.tcp_keepalive_time = 7200' >> /etc/sysctl.conf
+  fi
   echo 'configure_internet_protocol' >> $COMPLETION_FILE
 }