From 0fbddf1cd735a29282415aa0dae370bad9af5462 Mon Sep 17 00:00:00 2001
From: Vadim Rutkovsky <vrutkovs@redhat.com>
Date: Wed, 5 Feb 2020 21:38:00 +0100
Subject: [PATCH] GCP: add a script and a service which ensure GCP routes are
 set correctly

This would ensure bootstrap node reports as healthy to GCP LBs
---
 .../gcp/files/usr/local/bin/gcp-routes.sh     | 91 +++++++++++++++++++
 .../systemd/units/gcp-routes.service          | 16 ++++
 2 files changed, 107 insertions(+)
 create mode 100644 data/data/bootstrap/gcp/files/usr/local/bin/gcp-routes.sh
 create mode 100644 data/data/bootstrap/systemd/units/gcp-routes.service

diff --git a/data/data/bootstrap/gcp/files/usr/local/bin/gcp-routes.sh b/data/data/bootstrap/gcp/files/usr/local/bin/gcp-routes.sh
new file mode 100644
index 00000000000..3567ce4850a
--- /dev/null
+++ b/data/data/bootstrap/gcp/files/usr/local/bin/gcp-routes.sh
@@ -0,0 +1,91 @@
+#!/bin/bash
+
+declare -A routes
+curler() {
+  curl --silent -L -H "Metadata-Flavor: Google" "http://metadata.google.internal/computeMetadata/v1/instance/${1}"
+}
+
+get_ifname() {
+  sysfs_path="/sys/class/net"
+  for dev in $(find ${sysfs_path} -maxdepth 1  -mindepth 1);
+  do
+      local mac=$(<${dev}/address);
+      local name="$(basename ${dev})"
+      if [ "${mac}" == "${1}" ];
+      then
+          echo "${name}"
+          return;
+      fi
+  done
+}
+
+set_routes() {
+  local dev="${1}"
+  read -a dev_routes <<< "${routes[$dev]}"
+  for cur_route in $(ip route show dev ${dev} table local proto 66 | awk '{print$2}');
+  do
+      if [[ ! "${dev_routes[@]}" =~ "${cur_route}" ]];
+      then
+          echo "Removing stale forwarded IP ${cur_route}/32"
+          ip route del ${cur_route}/32 dev ${dev} table local proto 66
+      fi
+  done
+  for route in ${dev_routes[@]}
+  do
+      ip route replace to local ${route} dev $dev proto 66
+  done
+  unset dev_routes
+}
+
+del_routes() {
+  local dev="${1}"
+  read -a dev_routes <<< "${routes[$dev]}"
+  for cur_route in $(ip route show dev ${dev} table local proto 66 | awk '{print$2}');
+  do
+      if [[ "${dev_routes[@]}" =~ "${cur_route}" ]];
+      then
+          echo "Removing forwarded IP ${cur_route}/32"
+          ip route del ${cur_route}/32 dev ${dev} table local proto 66
+      fi
+  done
+  unset dev_routes
+}
+
+run() {
+  net_path="network-interfaces/"
+  for vif in $(curler ${net_path}); do
+      hw_addr=$(curler "${net_path}${vif}mac")
+      fwip_path="${net_path}${vif}forwarded-ips/"
+      dev_name="$(get_ifname ${hw_addr})"
+      for level in $(curler ${fwip_path})
+      do
+          for fwip in $(curler ${fwip_path}${level})
+          do
+              echo "Processing route for NIC ${vif}${hw_addr} as ${dev_name} for ${fwip}"
+              routes[$dev_name]+="${fwip} "
+          done
+      done
+      $"${1}" ${dev_name}
+
+      routes[$dev_name]=""
+      unset hw_addr
+      unset fwip_path
+      unset dev_name
+  done
+}
+
+case "$1" in
+  start)
+    while :; do
+      run set_routes
+      sleep 30
+    done
+    ;;
+  cleanup)
+    run del_routes
+    ;;
+  *)
+    echo $"Usage: $0 {start|cleanup}"
+    exit 1
+
+esac
diff --git a/data/data/bootstrap/systemd/units/gcp-routes.service b/data/data/bootstrap/systemd/units/gcp-routes.service
new file mode 100644
index 00000000000..75e7ddb5e28
--- /dev/null
+++ b/data/data/bootstrap/systemd/units/gcp-routes.service
@@ -0,0 +1,16 @@
+[Unit]
+Description=Update GCP routes for forwarded IPs.
+ConditionKernelCommandLine=|ignition.platform.id=gce
+ConditionKernelCommandLine=|ignition.platform.id=gcp
+After=network.target
+
+[Service]
+Type=simple
+ExecStart=/bin/bash /usr/local/bin/gcp-routes.sh start
+ExecStopPost=/bin/bash /usr/local/bin/gcp-routes.sh cleanup
+User=root
+RestartSec=30
+Restart=always
+
+[Install]
+WantedBy=multi-user.target