Best way to Autoupdate is.
add a update.txt file in your steamcmd folder.
Code:
@ShutdownOnFailedCommand 0
@NoPromptForPassword 0
login anonymous
force_install_dir /home/gs/csgoserver
app_update 740
quit
add to your server run.sh
Code:
-autoupdate -steam_dir /home/steamcmd -steamcmd_script /home/steamcmd/update.txt
it updates at every srcds update and check on each start/restart.