Support healthcheck with relative URL

traditional one with relative url always returns 404 (unhealthy).
Now we can use ${GITLAB_RELATIVE_URL_ROOT} variable to set healcheck URL
after moving script generation to runtime,

assets/build/install.sh

@@ -423,17 +423,6 @@ programs=sshd,nginx,mail_room,cron
 priority=20
 EOF
 
-# configure healthcheck script
-## https://docs.gitlab.com/ee/user/admin_area/monitoring/health_check.html
-cat > /usr/local/sbin/healthcheck <<EOF
-#!/bin/bash
-url=http://localhost/-/liveness
-options=( '--insecure' '--location' '--silent' )
-curl "\${options[@]}" \$url
-[[ "\$(curl \${options[@]} -o /dev/null -I -w '%{http_code}' \$url)" == "200" ]]
-EOF
-chmod +x /usr/local/sbin/healthcheck
-
 # purge build dependencies and cleanup apt
 DEBIAN_FRONTEND=noninteractive apt-get purge -y --auto-remove ${BUILD_DEPENDENCIES}
 rm -rf /var/lib/apt/lists/*

assets/runtime/functions

@@ -1523,6 +1523,19 @@ update_ssh_listen_port() {
   sed -i "s|#Port 22|Port ${GITLAB_SSH_LISTEN_PORT}|g" /etc/ssh/sshd_config
 }
 
+generate_healthcheck_script() {
+  # configure healthcheck script
+  ## https://docs.gitlab.com/ee/user/admin_area/monitoring/health_check.html
+cat > /usr/local/sbin/healthcheck <<EOF
+#!/bin/bash
+url=http://localhost${GITLAB_RELATIVE_URL_ROOT}/-/liveness
+options=( '--insecure' '--location' '--silent' )
+curl "\${options[@]}" \$url
+[[ "\$(curl \${options[@]} -o /dev/null -I -w '%{http_code}' \$url)" == "200" ]]
+EOF
+  chmod +x /usr/local/sbin/healthcheck
+}
+
 initialize_system() {
   map_uidgid
   initialize_logdir
@@ -1665,6 +1678,7 @@ configure_gitlab() {
   gitlab_configure_registry
   gitlab_configure_pages
   gitlab_configure_sentry
+  generate_healthcheck_script
 
   # remove stale gitlab.socket
   rm -rf ${GITLAB_INSTALL_DIR}/tmp/sockets/gitlab.socket