This patch removes duplicate internal copies of constants in the structs
package which are also defined in the api package. The api.KVOp type
with all its values for the TXN endpoint and the api.HealthXXX constants
are now used throughout the codebase.
This resulted in some circular dependencies in the testutil package
which have been resolved by copying code and constants and moving the
WaitForLeader function into a separate testrpc package.
This patch provides additional attribute to the notification mock in
order to protect an access to the internal maps from multiple
go-routines. This is required to prevent panic errors caused by
inconsistent map state.
This experiment was brought about because of variable naming
confusion where name and checkIDs were interchanged. Gave CheckID
an Qualified Type Name and chased downstream changes.
Adds the ability to simply check whether a TCP socket accepts
connections to determine if it is healthy. This is a light-weight -
though less comprehensive than scripting - method of checking network
service health.
The check parameter `tcp` should be set to the `address:port`
combination for the service to be tested. Supports both IPv6 and IPv4,
in the case of a hostname that resolves to both, connections will be
attempted via both protocol versions, with the first successful
connection returning a successful check result.
Example check:
```json
{
"check": {
"id": "ssh",
"name": "SSH (TCP)",
"tcp": "example.com:22",
"interval": "10s"
}
}
```
Apparently the execution of `TestCheckTTL` could sometime take > 10ms
causing it to fail. This commit will eliminate the race condition for
most modern hardware.
