Bug 1837122: templates: add etc-networkmanager-dispatcher.d-90-long-hostname.yaml

templates/common/_base/files/etc-networkmanager-dispatcher.d-90-long-hostname.yaml

@@ -0,0 +1,40 @@
+filesystem: "root"
+mode: 0755
+path: "/etc/NetworkManager/dispatcher.d/90-long-hostname"
+contents:
+  inline: |
+    #!/bin/bash
+    #
+    # On Google Compute Platform (GCP) the hostname may be too long (>63 chars).
+    # During firstboot the hostname is set in the initramfs before NetworkManager
+    # runs; on reboot affect nodes use 'localhost'. This hook is a simple work
+    # around: if the host name is longer than 63 characters, then the hostname
+    # is truncated at the _first_ dot.
+    #
+    # Additionally, this hook does not break DNS or cluster DNS resolution,
+    # since NetworkManager sets the appropriate /etc/resolv.conf settings.
+
+    IF=$1
+    STATUS=$2
+
+    log() { logger --tag "network-manager/$(basename $0)" "${@}"; }
+
+    # capture all eligible hostnames
+    if [[ ! "$(/bin/hostname)" =~ (localhost|localhost.local) ]]; then
+        log "hostname is already set"
+        exit 0
+    fi
+
+    if [[ ! "$STATUS" =~ (up|hostname|dhcp4-change|dhcp6-change) ]]; then
+        exit 0
+    fi
+
+    default_host="${DHCP4_HOST_NAME:-$DHCP6_HOST_NAME}"
+    # truncate the hostname to the first dot and than 64 characters.
+    host=$(echo ${default_host} | cut -f1 -d'.' | cut -c -63)
+
+    if [ "${#default_host}" -gt 63 ]; then
+        log "discovered hostname is longer than than 63 characters"
+        log "truncating ${default_host} => ${host}"
+        /bin/hostnamectl --transient set-hostname "${host}"
+    fi