chore: convert agent stats to use a table (#6374)

* chore: convert workspace agent stats from json to table

* chore: convert agent stats to use a table

Backwards compatibility becomes hard when all agent stats are in a JSON blob.
We also want to query this table for new agents that are failing health checks
so we can display it in the UI.

* Fix migration using default values

codersdk/agentsdk/agentsdk.go

@@ -397,7 +397,7 @@ func (c *Client) ReportStats(ctx context.Context, log slog.Logger, statsChan <-c
 	}
 
 	// Send an empty stat to get the interval.
-	postStat(&Stats{ConnsByProto: map[string]int64{}})
+	postStat(&Stats{ConnectionsByProto: map[string]int64{}})
 
 	go func() {
 		defer close(exited)
@@ -426,10 +426,10 @@ func (c *Client) ReportStats(ctx context.Context, log slog.Logger, statsChan <-c
 // Stats records the Agent's network connection statistics for use in
 // user-facing metrics and debugging.
 type Stats struct {
-	// ConnsByProto is a count of connections by protocol.
-	ConnsByProto map[string]int64 `json:"conns_by_proto"`
-	// NumConns is the number of connections received by an agent.
-	NumConns int64 `json:"num_comms"`
+	// ConnectionsByProto is a count of connections by protocol.
+	ConnectionsByProto map[string]int64 `json:"conns_by_proto"`
+	// ConnectionCount is the number of connections received by an agent.
+	ConnectionCount int64 `json:"num_comms"`
 	// RxPackets is the number of received packets.
 	RxPackets int64 `json:"rx_packets"`
 	// RxBytes is the number of received bytes.

codersdk/workspaceagents_test.go

@@ -79,7 +79,7 @@ func TestAgentReportStats(t *testing.T) {
 	chanLen := 3
 	statCh := make(chan *agentsdk.Stats, chanLen)
 	for i := 0; i < chanLen; i++ {
-		statCh <- &agentsdk.Stats{ConnsByProto: map[string]int64{}}
+		statCh <- &agentsdk.Stats{ConnectionsByProto: map[string]int64{}}
 	}
 
 	ctx := context.Background()