If the local Consul agent is not available while attempting to step down from active or up to active, retry once a second. Allow for concurrent changes to the state with a single registration updater. Fix standby initialization.
Vault will now register itself with Consul. The active node can be found using `active.vault.service.consul`. All standby vaults are available via `standby.vault.service.consul`. All unsealed vaults are considered healthy and available via `vault.service.consul`. Change in status and registration is event driven and should happen at the speed of a write to Consul (~network RTT + ~1x fsync(2)).
Healthy/active:
```
curl -X GET 'http://127.0.0.1:8500/v1/health/service/vault?pretty' && echo;
[
{
"Node": {
"Node": "vm1",
"Address": "127.0.0.1",
"TaggedAddresses": {
"wan": "127.0.0.1"
},
"CreateIndex": 3,
"ModifyIndex": 20
},
"Service": {
"ID": "vault:127.0.0.1:8200",
"Service": "vault",
"Tags": [
"active"
],
"Address": "127.0.0.1",
"Port": 8200,
"EnableTagOverride": false,
"CreateIndex": 17,
"ModifyIndex": 20
},
"Checks": [
{
"Node": "vm1",
"CheckID": "serfHealth",
"Name": "Serf Health Status",
"Status": "passing",
"Notes": "",
"Output": "Agent alive and reachable",
"ServiceID": "",
"ServiceName": "",
"CreateIndex": 3,
"ModifyIndex": 3
},
{
"Node": "vm1",
"CheckID": "vault-sealed-check",
"Name": "Vault Sealed Status",
"Status": "passing",
"Notes": "Vault service is healthy when Vault is in an unsealed status and can become an active Vault server",
"Output": "",
"ServiceID": "vault:127.0.0.1:8200",
"ServiceName": "vault",
"CreateIndex": 19,
"ModifyIndex": 19
}
]
}
]
```
Healthy/standby:
```
[snip]
"Service": {
"ID": "vault:127.0.0.2:8200",
"Service": "vault",
"Tags": [
"standby"
],
"Address": "127.0.0.2",
"Port": 8200,
"EnableTagOverride": false,
"CreateIndex": 17,
"ModifyIndex": 20
},
"Checks": [
{
"Node": "vm2",
"CheckID": "serfHealth",
"Name": "Serf Health Status",
"Status": "passing",
"Notes": "",
"Output": "Agent alive and reachable",
"ServiceID": "",
"ServiceName": "",
"CreateIndex": 3,
"ModifyIndex": 3
},
{
"Node": "vm2",
"CheckID": "vault-sealed-check",
"Name": "Vault Sealed Status",
"Status": "passing",
"Notes": "Vault service is healthy when Vault is in an unsealed status and can become an active Vault server",
"Output": "",
"ServiceID": "vault:127.0.0.2:8200",
"ServiceName": "vault",
"CreateIndex": 19,
"ModifyIndex": 19
}
]
}
]
```
Sealed:
```
"Checks": [
{
"Node": "vm2",
"CheckID": "serfHealth",
"Name": "Serf Health Status",
"Status": "passing",
"Notes": "",
"Output": "Agent alive and reachable",
"ServiceID": "",
"ServiceName": "",
"CreateIndex": 3,
"ModifyIndex": 3
},
{
"Node": "vm2",
"CheckID": "vault-sealed-check",
"Name": "Vault Sealed Status",
"Status": "critical",
"Notes": "Vault service is healthy when Vault is in an unsealed status and can become an active Vault server",
"Output": "Vault Sealed",
"ServiceID": "vault:127.0.0.2:8200",
"ServiceName": "vault",
"CreateIndex": 19,
"ModifyIndex": 38
}
]
```
