Add syslog level configuration and add info logs during startup

[vtikoo]

Summary

• Syslog level can be specified either via --syslog-level command line option or SyslogLevel in the JSON configuration.
• Added info logs on mystikos kernel entry and before jumping to C runtime. These can be helpful to debug startup failures.

Signed-off-by: Vikas Tikoo vikasamar@gmail.com

[radhikaj]

Thanks @vtikoo for adding this. Can you also document your config additions here: https://github.com/deislabs/mystikos/blob/main/doc/sign-package.md (I dont know where CLI is documented)

[mikbras]

Looks great Vikas. Two things:
- See minor comments
- Might be nice to show --syslog-level option in the --help.

Thank you for doing this.

[paulcallen]

the main kernel log reporter dmesg allows you to specify which specific levels you want like this:
sudo dmesg --level=emerg,alert,crit,err,warn,notice,info,debug

You can remove err and display everything but that!

[vtikoo]

Thanks @vtikoo for adding this. Can you also document your config additions here: https://github.com/deislabs/mystikos/blob/main/doc/sign-package.md (I dont know where CLI is documented)

Thanks @radhikaj, had forgotten about updating the packaging docs. The CLI option is documented in the usage/help string.

[vtikoo]

the main kernel log reporter dmesg allows you to specify which specific levels you want like this: sudo dmesg --level=emerg,alert,crit,err,warn,notice,info,debug

Thanks for sharing this @paulcallen. Had to change warning to warn to match with these.

[mikbras]

Thank you Vikas for doing this. Looks great. I am approving but not sure if others have outstanding requetss.