What is the tails-server-base-url? and how should it be configured?

Question

I have installed the indy-sdk in my system and started the ledger network (It is running). After that I setup the aries-cloudagent and ran the agent (as a steward) using the aca-py command.

Now, with the help of this agent, I have published the schema on the ledger, but when I am trying to send a credential definition on the ledger.. It is giving me the error :- 400: tails_server_base_url not configured..

Can anyone explain what is it and how can it be resolved?

Answer 1

This error is because your credential has support_revocation flag set to true.

If your credential don't need revocation support you can set this flag to false and the credential_definition will work.

If you need revocation support you should update your aries version to 0.5.6 and configure a tail file for revocation.

Answer 2

In case your goal is to have revocation enabled.

If you check on the Ledger, the Credential Definition is published anyway on the ledger even though the 400 tails_server_base_url not configured error.

The Correct way to define a revocable credential:

Set the --tails-server-base-url parameter on the "aca-py start" the agent will create and publish the revocation registry automatically when sending the Credential Definition with revocation_support=true

To spin-up the tails-server look at: https://github.com/hyperledger/aries-cloudagent-python/blob/main/docs/GettingStartedAriesDev/CredentialRevocation.md

• with ngrok: --tails-server-base-url http://[random].ngrok.io
• without ngrok, directly on docker: --tails-server-base-url http://172.17.01:6543

clone the repo: https://github.com/bcgov/indy-tails-server

./manage start

and then put the ngrok URL in the --tails-server-base-url parameter.

For more information: https://ldej.nl/post/becoming-a-hyperledger-aries-developer-part-6-revocation/ Theory on Tails files: https://github.com/hyperledger/indy-hipe/tree/master/text/0011-cred-revocation