How to properly read parameters from the yamcs.$project.yaml configuration

[Patrick Dohmen]

Hello group,

I am struggling while trying to read the configuration of the parameters to my CommandPostProcessor.

Trying to read the following does not work:

// Load secret key from configuration

if (config.containsKey("secretKey")) {

this.secretKey = config.getString("secretKey");

} else {

// Consider loading from environment variable as a more secure alternative

this.secretKey = System.getenv("YAMCS_HMAC_SECRET_KEY");

if (this.secretKey == null) {

throw new IllegalArgumentException(

"HMAC secret key must be provided via 'secretKey' config or YAMCS_HMAC_SECRET_KEY environment variable");

}

}

The configuration is as follows:

virtualChannels:

- vcId: 0 # VCID_MANAGEMENT

service: "PACKET"

commandPostprocessorClassName: com.erminaz.MyCommandPostprocessor

#commandPostprocessorArgs:

args:

secretKey: "your-base64-secret-key"

algorithm: "HmacSHA256"

#hmacLength: 16 # Optional: truncate to 16 bytes

I've just attached to most interesting parts for readability, if you're suggesting that the mistake I am doing is somewhere else in those files I can link to a repository.

Best regards,

Patrick, DL4PD

[fabia...@spaceapplications.com]

Configuration options for a postprocessor would need to be provided with commandPostprocessorArgs (commented out in your picture)

[Patrick Dohmen]

Neither of both approaches did work, that's why I left the commented regions.

Could you give an example on how this should work?

Thanks for having a look!

[Patrick Dohmen]

Finally:

It was an indentation error in the map...

Geez...

Thanks for your efforts!

fabia...@spaceapplications.com schrieb am Montag, 12. Januar 2026 um 11:15:02 UTC+1: