What purpose does each of the Greengrass V2 config files have?

1

Hi,

I see there are multiple files under the /greengrass/v2/config folder on my GG Core device (see screenshot below), please can someone confirm what the purpose of each of these is?

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cgddrd
asked 9 months ago275 views
1 Answer
2
Accepted Answer

Hello,

Files ending with ~ are backup files which show the last state of the file before the current state. These are sometimes used if the primary file is detected to be corrupted in order to attempt an automatic recovery.

  1. bootstrap.tlog - initial configuration which should only be written one time and will contain minimal information, just enough to try and connect to AWS IoT Core in case the primary configuration file (config.tlog) is misisng or corrupted.
  2. config.tlog - the primary configuration file, the source of truth for everything Greengrass does on the device
  3. config.yaml - Greengrass did not create this file, you must have put it there during the install, perhaps following the 'manual provisioning' steps.
  4. effectiveConfig.yaml - A human-readable dump of the config.tlog file which is written by Greengrass on startup and shutdown; it will not show the current config state.

Cheers,

Michael

AWS
EXPERT
answered 9 months ago
AWS
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reviewed 9 months ago
profile pictureAWS
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reviewed 9 months ago
  • Thanks Michael, this is super helpful and you're correct to say config.yaml is one we created as part of manual provisioning yes (I should have made this clear so apologies for that).

    A couple of quick follow up questions if that's ok?

    1. So it's actually config.tlog that the Nucleus actually reads from to acquire it's settings when starting up yes?

    2. If effectiveConfig.yaml is just a human-readable dump of config.tlog (and not actually read/used by GG itself) why would you need a backup version?

    1. Yes, that's the ultimate source of truth.
    2. We don't need a backup, but we're just using the same code which creates a backup when writing all of these files.

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