Ledger with remote signer - health check

Question

I have a http remote signer connected to a Ledger and it works fine. The ledger is running the baking app.

I want to check periodically that the remote signer is able to sign.

How can I do that ?

Doing curl http://<remote signer>:<port>/keys/<mykey> is not a solution as it will return no error even when the ledger is disconnected.

The command below will work fine on an address on the remote signer but fail when targeting a ledger address:

me@mymachine ~/workspace/tezos () $ ./tezos-client  sign bytes 0x02$(echo "hi there!" | xxd -ps | tr -d '\n') for remote_signer_ledger                                                                                                                                                                               
Warning:                                                                                                                                                                                                                                                                                                                      

                 This is NOT the Tezos Mainnet.                                                                                                                                                                                                                                                                               

     The node you are connecting to claims to be running on the                                                                                                                                                                                                                                                               
               Tezos Alphanet DEVELOPMENT NETWORK.                                                                                                                                                                                                                                                                            
          Do NOT use your fundraiser keys on this network.                                                                                                                                                                                                                                                                    
          Alphanet is a testing network, with free tokens.                                                                                                                                                                                                                                                                    

Error:                                                                                                                                                                                                                                                                                                                        
  Unregistred error:                                                                                                                                                                                                                                                                                                          
    { "kind": "permanent", "id": "signer.ledger",                                                                                                                                                                                                                                                                             
      "ledger-error":                                                                                                                                                                                                                                                                                                         
        "Application level error (sign): Unregistered status message" }             

I tried different magic bytes, nothing works. Presumably, 0x02 (endorsment) should work as it does not check against the high watermark.

How can I craft an endorsement signature request ?

Can I replay a valid endorsment request from the past ?

Is there any other way to verify that the ledger is connected and baking app launched ?

Answer 1

A good way to check that your ledger device is connected, the Baking App is open, and it is authorized to bake is to run the command tezos-client get ledger authorized path for <account-alias-or-ledger-uri>.