feat: add a metric to let cosmos consumer chains see their last valset update

[fastfadingviolets]

PR(Pull Request) Overview

Added a metric to expose the last block height at which a consumer chain received a validator set update. This allows validators to ensure that relay channels are still up and that the ccv module is working as expected. I couldn't find an uptime_test.go so I didn't add a test, but let me know where it should go and I'll add it.

Changes

• Major feature addition or modification
• Bug fix
• Code improvement
• Documentation update

Related Issue

Description of Changes

Added code to fetch the block height when a consumer chain last received a validator set update. Exposed a prometheus metric with the block time. Also added a commented-out example alert rule in uptime.yaml that'll alert when it's been > 5000 blocks since the last valset update. This can be indicative of relayer issues, and should be investigated in all cases.

Testing Method

1. Try the following config.yaml:

chains: 
  - display_name: 'gaia-1'
    chain_id: cosmoshub-4
    tracking_addresses: []
    nodes:
      - rpc: 'https://cosmos-rpc.stakeandrelax.net/'
        api: 'https://cosmos-api.stakeandrelax.net/'
        grpc: 'cosmos-grpc.stakeandrelax.net:15090'
  - display_name: 'neutron'
    chain_id: neutron-1
    tracking_addresses: []
    nodes:
      - rpc: 'https://rpc.neutron.quokkastake.io/'
        api: 'https://api.neutron.quokkastake.io/'
        grpc: 'rpc.neutron.quokkastake.io:9090'
    provider_nodes:
      - rpc: 'https://cosmos-rpc.stakeandrelax.net/'
        api: 'https://cosmos-api.stakeandrelax.net/'
        grpc: 'cosmos-grpc.stakeandrelax.net:15090'

2. cvms will now expose a metric called cvms_uptime_last_ccv_update that should give you the block height at last CCV update for Neutron mainnet.
3. You may then query it as max by(chain_id) (cvms_block_height) - on(chain_id) cvms_uptime_last_ccv_update and it looks like this:
   

Additional Information

[jeongseup]

Thank you for contributing @fastfadingviolets I'll review this PR for a few days. our team is developing babylon and axelar amplifier packages. Please understand us

[fastfadingviolets]

Thank you for contributing @fastfadingviolets I'll review this PR for a few days. our team is developing babylon and axelar amplifier packages. Please understand us

No worries @jeongseup totally get it, please take your time!