fix: support CentOS cloud image (#606)

https://bugzilla.redhat.com/show_bug.cgi?id=1332025

report/util.go

@@ -378,7 +378,7 @@ func isCveInfoUpdated(cveID string, previous, current models.ScanResult) bool {
 		}
 	}
 	for _, cType := range cTypes {
-		if equal := prevLastModified[cType].Equal(curLastModified[cType]); !equal {
+		if !prevLastModified[cType].Equal(curLastModified[cType]) {
 			return true
 		}
 	}

scan/redhat.go

@@ -78,6 +78,28 @@ func detectRedhat(c config.ServerInfo) (itsMe bool, red osTypeInterface) {
 		}
 	}
 
+	// https://bugzilla.redhat.com/show_bug.cgi?id=1332025
+	// CentOS cloud image
+	if r := exec(c, "ls /etc/centos-release", noSudo); r.isSuccess() {
+		if r := exec(c, "cat /etc/centos-release", noSudo); r.isSuccess() {
+			re := regexp.MustCompile(`(.*) release (\d[\d\.]*)`)
+			result := re.FindStringSubmatch(strings.TrimSpace(r.Stdout))
+			if len(result) != 3 {
+				util.Log.Warn("Failed to parse CentOS version: %s", r)
+				return true, red
+			}
+
+			release := result[2]
+			switch strings.ToLower(result[1]) {
+			case "centos", "centos linux":
+				red.setDistro(config.CentOS, release)
+				return true, red
+			default:
+				util.Log.Warn("Failed to parse CentOS: %s", r)
+			}
+		}
+	}
+
 	if r := exec(c, "ls /etc/redhat-release", noSudo); r.isSuccess() {
 		// https://www.rackaid.com/blog/how-to-determine-centos-or-red-hat-version/
 		// e.g.