initiala health.go

1 files changed, 70 insertions, 0 deletions

diff --git a/health.go b/health.go
new file mode 100644
index 0000000..39685b1
--- /dev/null
+++ b/health.go
@@ -0,0 +1,70 @@
+package main
+
+import "strings"
+
+type alertSeverity int
+
+const (
+	ok alertSeverity = iota
+	warning
+	critical
+	unknown
+)
+
+func (s alertSeverity) String() string {
+	switch s {
+	case ok:
+		return "OK"
+	case warning:
+		return "WARNING"
+	case critical:
+		return "CRITICAL"
+	case unknown:
+		return "UNKNOWN"
+	default:
+		panic("encountered an unknown alertSeverity")
+	}
+}
+
+type alert struct {
+	text     string
+	severity alertSeverity
+}
+
+type healthStatus struct {
+	alerts map[string]alert
+}
+
+func newHealthStatus() healthStatus {
+	return healthStatus{
+		alerts: make(map[string]alert),
+	}
+}
+
+func (hs healthStatus) String() string {
+	var (
+		alertsBySeverity [4][]string
+		sb               strings.Builder
+	)
+
+	for _, alert := range hs.alerts {
+		alertsBySeverity[alert.severity] = append(alertsBySeverity[alert.severity], alert.text)
+	}
+
+	possible := [4]alertSeverity{ok, warning, critical, unknown}
+	for _, severity := range possible {
+		if len(alertsBySeverity[severity]) == 0 {
+			continue
+		}
+		for _, alert := range alertsBySeverity[severity] {
+			sb.WriteString(alert)
+			sb.WriteString("\n")
+		}
+	}
+
+	result := sb.String()
+	if result == "" {
+		return "OK: all is fine"
+	}
+	return result
+}