Fix API stuck in updating state after API has crashed (#1691)

Author: RobertLucian

pkg/workloads/cortex/serve/init/bootloader.sh

@@ -95,7 +95,10 @@ create_s6_service() {
     # https://skarnet.org/software/s6/s6-svscanctl.html
     # http://skarnet.org/software/s6/s6-svc.html
     # http://skarnet.org/software/s6/servicedir.html
+
+    # good pages to read about execline
     # http://www.troubleshooters.com/linux/execline.htm
+    # https://danyspin97.org/blog/getting-started-with-execline-scripting/
 
     service_name=$1
     cmd=$2
@@ -110,7 +113,7 @@ create_s6_service() {
 
     dest_script="$dest_dir/finish"
     echo "#!/usr/bin/execlineb -S0" > $dest_script
-    echo "ifelse { s6-test \${1} -ne 0 } { s6-svscanctl -t /var/run/s6/services }" >> $dest_script
+    echo "ifelse { s6-test \${1} -ne 0 } { foreground { redirfd -w 1 /var/run/s6/env-stage3/S6_STAGE2_EXITED s6-echo -n -- \${1} } s6-svscanctl -t /var/run/s6/services }" >> $dest_script
     echo "s6-svc -O /var/run/s6/services/$service_name" >> $dest_script
     chmod +x $dest_script
 }