Improvement to TCHC's logging around TO failure (#7776)

* Adding status code for TO

* Adding improved logging for TO interaction

* Adding revised Change log.

* Fixing arg issues.

---------

Co-authored-by: Tyler Morgan <tylermorgan210@gmail.com>

CHANGELOG.md

@@ -52,6 +52,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - [#7784](https://github.com/apache/trafficcontrol/pull/7784) *Traffic Portal* Added revert certificate functionality to the ssl-keys page.
 
 ### Changed
+- [#7776](https://github.com/apache/trafficcontrol/pull/7776) *tc-health-client* Added error message while issues interacting with Traffic Ops.
 - [#7757](https://github.com/apache/trafficcontrol/pull/7757) *Traffic Router* Changed Traffic Router to point to api version 5.0 of Traffic Ops.
 - [#7732](https://github.com/apache/trafficcontrol/pull/7732) *Traffic Router* Increased negative TTL value to 900 seconds.
 - [#7761](https://github.com/apache/trafficcontrol/pull/7761) *Traffic Monitor* Use API v5 for the TM's Traffic Ops client, and use TO API v4 for TM's Traffic Ops legacy client

tc-health-client/tc-health-client.go

@@ -206,11 +206,11 @@ func reloadConfig(pi *tmagent.ParentInfo) {
 
 	if isNew {
 		if err = config.ReadCredentials(newCfg, false); err != nil {
-			log.Errorln("could not load credentials for config updates, keeping the old config")
+			log.Errorf("could not load credentials for config updates, keeping the old config: %v", err.Error())
 			return
 		}
 		if err = pi.GetTOData(newCfg); err != nil {
-			log.Errorln("could not update the list of trafficmonitors, keeping the old config")
+			log.Errorf("could not update the list of trafficmonitors, keeping the old config: %v", err.Error())
 		} else {
 			// TODO this was calling a custom copy func that wasn't copying:
 			//      MarkUpPollThreshold, TmProxyURL, CredentialFile, ParsedProxyURL

tc-health-client/tmagent/tmagent.go

@@ -663,12 +663,15 @@ func (pi *ParentInfo) GetTOData(cfg *config.Cfg) error {
 		}
 	}
 
-	srvs, _, err := toData.TOClient.GetServers(toclient.NewRequestOptions())
+	srvs, reqInf, err := toData.TOClient.GetServers(toclient.NewRequestOptions())
 	if err != nil {
 		// next time we'll login again and get a new session.
 		toData.TOClient = nil
 		pi.TOData.Set(toData)
 		return errors.New("error fetching Trafficmonitor server list: " + err.Error())
+	} else if reqInf.StatusCode >= 300 || reqInf.StatusCode < 200 {
+		// Provide logging around a potential issue
+		return fmt.Errorf("Traffic Ops returned a non 2xx status code. Expected 2xx, got %v", reqInf.StatusCode)
 	}
 
 	toData.Monitors = map[string]struct{}{}

tc-health-client/tmagent/tmhealthservice.go

@@ -108,7 +108,7 @@ func doPollAndUpdateCacheStatus(pi *ParentInfo, doTrafficOpsReq bool) {
 	if err != nil {
 		log.Errorf("poll-status %v\n", err.Error())
 		if err := pi.GetTOData(cfg); err != nil {
-			log.Errorln("update event=\"could not update the list of trafficmonitors, keeping the old config\"")
+			log.Errorf("update event=\"could not update the list of trafficmonitors, keeping the old config\": %v", err.Error())
 		} else {
 			log.Infoln("service-status service=tm-health event=\"updated TrafficMonitor statuses from TrafficOps\"")
 		}
@@ -132,7 +132,7 @@ func doPollAndUpdateCacheStatus(pi *ParentInfo, doTrafficOpsReq bool) {
 	if doTrafficOpsReq {
 		// TODO move to its own TO poller
 		if err = pi.GetTOData(cfg); err != nil {
-			log.Errorln("update event=\"could not update the list of trafficmonitors, keeping the old config\"")
+			log.Errorf("update event=\"could not update the list of trafficmonitors, keeping the old config\": %v", err.Error())
 		} else {
 			log.Infoln("service-status service=tm-health event=\"updated TrafficMonitor statuses from TrafficOps\"")
 		}