sending err back to fetch to trigger backoff retry

[aswanidutt]

issue: When a rotating secret that has rotation_period but ttl=0, it should not be treated as a rotating secret. Instead, it should wait and retry exponentially using default retry_config

What Changed:

• Modified leaseCheckWait() to return (time.Duration, error) instead of just time.Duration
• Added error for TTL=0 detection
• When a rotating secret returns ttl=0, the error propagates to trigger the existing retry mechanism
• Updated VaultReadQuery and VaultWriteQuery to handle and propagate the error
• Added comprehensive test coverage for TTL=0 scenarios

Fixes: VAULT-38829-https://hashicorp.atlassian.net/browse/VAULT-38829?

before this change: checking to rotate every second

tested by adding custom retry config in agent.hcl

vault {
  address = "http://127.0.0.1:8200"
  
  retry {
    attempts = 0          # Number of retry attempts (0 = unlimited)
  }
}
auto_auth {
  method "token_file" {
    min_backoff = "250ms"    # Minimum backoff time between retries
    max_backoff = "3m"       # Maximum backoff time between retries
    config = {
      token_file_path = "./auto-auth"
    }
  }
}

after the code change : Exponential backoff: 250ms,500ms,1s,2s, 4s, 8s, 16s, 32s, 64s, the max is 5m

[tvoran]

This is looking pretty good to me, just some minor suggestions in the test.

[tvoran]

I'm curious why the .Seconds() was dropped here? That seems to have forced a lot of changes unrelated to the goal of this PR that I'm not sure are necessary?

At this point I'd say either set this back to .Seconds(), or apply the suggestions I made to the rest of TestVaultRenewDuration():

• sending err back to fetch to trigger backoff retry #2136 (comment)
• sending err back to fetch to trigger backoff retry #2136 (comment)

[aswanidutt]

.Seconds() dropped because now the leaseCheckWait is returning multiple values not just duration but also error. updated with your suggestions to the rest of TestVaultRenewDuration():

[tvoran]

Minor suggestion in the test, but otherwise 👍

[tvoran]

It's probably still a good idea to check the value of err whenever leaseCheckWait() is called, just to be safe.

[Manishakumari-hc]

LGTM