add custom pre/post startup nodeinit script

Allows customization of nodeinit scripts to adapt node configuration before cilium is starting to allow eg. systemd configuration changes and reload of networkd.
This customization also allows a possibility to add hotfixes if node VMs needs fixed due to updates.

Signed-off-by: Markus Blaschke <mblaschke82@gmail.com>

Documentation/spelling_wordlist.txt

@@ -823,6 +823,7 @@ prepend
 prepended
 prepulls
 prerequirement
+prestop
 printf
 priori
 priorityClassName

install/kubernetes/cilium/files/nodeinit/prestop.bash

@@ -4,6 +4,8 @@ set -o errexit
 set -o pipefail
 set -o nounset
 
+{{ .Values.nodeinit.prestop.preScript }}
+
 if stat /tmp/node-deinit.cilium.io > /dev/null 2>&1; then
   exit 0
 fi
@@ -53,4 +55,6 @@ if iptables -w -t nat -L IP-MASQ > /dev/null; then
 fi
 {{- end }}
 
+{{ .Values.nodeinit.prestop.postScript }}
+
 echo "Node de-initialization complete"

install/kubernetes/cilium/files/nodeinit/startup.bash

@@ -14,6 +14,8 @@ echo "Addressing:"
 ip -4 a
 ip -6 a
 
+{{ .Values.nodeinit.startup.preScript }}
+
 {{- if .Values.nodeinit.removeCbrBridge }}
 if ip link show cbr0; then
   echo "Detected cbr0 bridge. Deleting interface..."
@@ -199,4 +201,7 @@ fi
 {{- if .Values.nodeinit.revertReconfigureKubelet }}
 rm -f /tmp/node-deinit.cilium.io
 {{- end }}
+
+{{ .Values.nodeinit.startup.postScript }}
+
 echo "Node initialization complete"

install/kubernetes/cilium/values.yaml.tmpl

@@ -2176,6 +2176,15 @@ nodeinit:
   # -- bootstrapFile is the location of the file where the bootstrap timestamp is
   # written by the node-init DaemonSet
   bootstrapFile: "/tmp/cilium-bootstrap.d/cilium-bootstrap-time"
+
+  # -- startup offers way to customize startup nodeinit script (pre and post position)
+  startup:
+   preScript: ""
+   postScript: ""
+  # -- prestop offers way to customize prestop nodeinit script (pre and post position)
+  prestop:
+   preScript: ""
+   postScript: ""
 
 preflight:
   # -- Enable Cilium pre-flight resources (required for upgrade)