Prepared statements prevent the use of connection multiplexing software
such as PGBouncer. Even when PGBouncer is configured for [session mode][1]
there's a possibility that a connection to PostgreSQL can be re-used by
different clients. This leads to errors when clients use session based
features (like prepared statements).
This change removes prepared statements from the PostgreSQL physical
backend. This will allow vault to successfully work in infrastructures
that employ the use of PGBouncer or other connection multiplexing
software.
[1]: https://pgbouncer.github.io/config.html#poolmode
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
}
]
```
