Whenever an upsert/deletion of a config entry happens, within the open
state store transaction we speculatively test compile all discovery
chains that may be affected by the pending modification to verify that
the write would not create an erroneous scenario (such as splitting
traffic to a subset that did not exist).
If a single discovery chain evaluation references two config entries
with the same kind and name in different namespaces then sometimes the
upsert/deletion would be falsely rejected. It does not appear as though
this bug would've let invalid writes through to the state store so the
correction does not require a cleanup phase.
This commit refactors the state store usage code to track unique service
name changes on transaction commit. This means we only need to lookup
usage entries when reading the information, as opposed to iterating over
a large number of service indices.
- Take into account a service instance's name being changed
- Do not iterate through entire list of service instances, we only care
about whether there is 0, 1, or more than 1.
We add a WriteTxn interface for use in updating the usage memdb table,
with the forward-looking prospect of incrementally converting other
functions to accept interfaces.
As well, we use the ReadTxn in new usage code, and as a side effect
convert a couple of existing functions to use that interface as well.
Using the newly provided state store methods, we periodically emit usage
metrics from the servers.
We decided to emit these metrics from all servers, not just the leader,
because that means we do not have to care about leader election flapping
causing metrics turbulence, and it seems reasonable for each server to
emit its own view of the state, even if they should always converge
rapidly.
And into token.Store. This change isolates any awareness of token
persistence in a single place.
It is a small step in allowing Agent.New to accept its dependencies.
This test was only passing because t.Parallel was causing every subtest to run with the last value in the iteration,
which sets a value for all tokens. The test started to fail once t.Parallel was removed, but the same failure could
have been produced by adding 'tt := tt' to the t.Run() func.
These tests run in under 10ms, so there is no reason to use t.Parallel.
This will apply cache throttling parameters are properly applied:
* cache.EntryFetchMaxBurst
* cache.EntryFetchRate
When values are updated, a log is displayed in info.
This might be better handled by allowing configuration for the InMemSink interval and retail, and disabling
the global. For now this is a smaller change to remove the goroutine leak caused by tests because go-metrics
does not provide any way of shutting down the global goroutine.
With this change, Agent.New() accepts many of the dependencies instead
of creating them in New. Accepting fully constructed dependencies from
a constructor makes the type easier to test, and easier to change.
There are still a number of dependencies created in Start() which can
be addressed in a follow up.
During gossip encryption key rotation it would be nice to be able to see if all nodes are using the same key. This PR adds another field to the json response from `GET v1/operator/keyring` which lists the primary keys in use per dc. That way an operator can tell when a key was successfully setup as primary key.
Based on https://github.com/hashicorp/serf/pull/611 to add primary key to list keyring output:
```json
[
{
"WAN": true,
"Datacenter": "dc2",
"Segment": "",
"Keys": {
"0OuM4oC3Os18OblWiBbZUaHA7Hk+tNs/6nhNYtaNduM=": 6,
"SINm887hKTzmMWeBNKTJReaTLX3mBEJKriDyt88Ad+g=": 6
},
"PrimaryKeys": {
"SINm887hKTzmMWeBNKTJReaTLX3mBEJKriDyt88Ad+g=": 6
},
"NumNodes": 6
},
{
"WAN": false,
"Datacenter": "dc2",
"Segment": "",
"Keys": {
"0OuM4oC3Os18OblWiBbZUaHA7Hk+tNs/6nhNYtaNduM=": 8,
"SINm887hKTzmMWeBNKTJReaTLX3mBEJKriDyt88Ad+g=": 8
},
"PrimaryKeys": {
"SINm887hKTzmMWeBNKTJReaTLX3mBEJKriDyt88Ad+g=": 8
},
"NumNodes": 8
},
{
"WAN": false,
"Datacenter": "dc1",
"Segment": "",
"Keys": {
"0OuM4oC3Os18OblWiBbZUaHA7Hk+tNs/6nhNYtaNduM=": 3,
"SINm887hKTzmMWeBNKTJReaTLX3mBEJKriDyt88Ad+g=": 8
},
"PrimaryKeys": {
"SINm887hKTzmMWeBNKTJReaTLX3mBEJKriDyt88Ad+g=": 8
},
"NumNodes": 8
}
]
```
I intentionally did not change the CLI output because I didn't find a good way of displaying this information. There are a couple of options that we could implement later:
* add a flag to show the primary keys
* add a flag to show json output
Fixes#3393.
Previsouly it was done in Agent.Start, which is much later then it needs to be.
The new 'dns' package was required, because otherwise there would be an
import cycle. In the future we should move more of the dns server into
the dns package.
