1 files changed, 123 insertions, 0 deletions
diff --git a/server/prometheus.js b/server/prometheus.js
new file mode 100644
index 0000000..f26125d
--- /dev/null
+++ b/server/prometheus.js
@@ -0,0 +1,123 @@
+const PrometheusClient = require("prom-client");
+const { log } = require("../src/util");
+
+const commonLabels = [
+    "monitor_name",
+    "monitor_type",
+    "monitor_url",
+    "monitor_hostname",
+    "monitor_port",
+];
+
+const monitorCertDaysRemaining = new PrometheusClient.Gauge({
+    name: "monitor_cert_days_remaining",
+    help: "The number of days remaining until the certificate expires",
+    labelNames: commonLabels
+});
+
+const monitorCertIsValid = new PrometheusClient.Gauge({
+    name: "monitor_cert_is_valid",
+    help: "Is the certificate still valid? (1 = Yes, 0= No)",
+    labelNames: commonLabels
+});
+const monitorResponseTime = new PrometheusClient.Gauge({
+    name: "monitor_response_time",
+    help: "Monitor Response Time (ms)",
+    labelNames: commonLabels
+});
+
+const monitorStatus = new PrometheusClient.Gauge({
+    name: "monitor_status",
+    help: "Monitor Status (1 = UP, 0= DOWN, 2= PENDING, 3= MAINTENANCE)",
+    labelNames: commonLabels
+});
+
+class Prometheus {
+    monitorLabelValues = {};
+
+    /**
+     * @param {object} monitor Monitor object to monitor
+     */
+    constructor(monitor) {
+        this.monitorLabelValues = {
+            monitor_name: monitor.name,
+            monitor_type: monitor.type,
+            monitor_url: monitor.url,
+            monitor_hostname: monitor.hostname,
+            monitor_port: monitor.port
+        };
+    }
+
+    /**
+     * Update the metrics page
+     * @param {object} heartbeat Heartbeat details
+     * @param {object} tlsInfo TLS details
+     * @returns {void}
+     */
+    update(heartbeat, tlsInfo) {
+
+        if (typeof tlsInfo !== "undefined") {
+            try {
+                let isValid;
+                if (tlsInfo.valid === true) {
+                    isValid = 1;
+                } else {
+                    isValid = 0;
+                }
+                monitorCertIsValid.set(this.monitorLabelValues, isValid);
+            } catch (e) {
+                log.error("prometheus", "Caught error");
+                log.error("prometheus", e);
+            }
+
+            try {
+                if (tlsInfo.certInfo != null) {
+                    monitorCertDaysRemaining.set(this.monitorLabelValues, tlsInfo.certInfo.daysRemaining);
+                }
+            } catch (e) {
+                log.error("prometheus", "Caught error");
+                log.error("prometheus", e);
+            }
+        }
+
+        if (heartbeat) {
+            try {
+                monitorStatus.set(this.monitorLabelValues, heartbeat.status);
+            } catch (e) {
+                log.error("prometheus", "Caught error");
+                log.error("prometheus", e);
+            }
+
+            try {
+                if (typeof heartbeat.ping === "number") {
+                    monitorResponseTime.set(this.monitorLabelValues, heartbeat.ping);
+                } else {
+                    // Is it good?
+                    monitorResponseTime.set(this.monitorLabelValues, -1);
+                }
+            } catch (e) {
+                log.error("prometheus", "Caught error");
+                log.error("prometheus", e);
+            }
+        }
+    }
+
+    /**
+     * Remove monitor from prometheus
+     * @returns {void}
+     */
+    remove() {
+        try {
+            monitorCertDaysRemaining.remove(this.monitorLabelValues);
+            monitorCertIsValid.remove(this.monitorLabelValues);
+            monitorResponseTime.remove(this.monitorLabelValues);
+            monitorStatus.remove(this.monitorLabelValues);
+        } catch (e) {
+            console.error(e);
+        }
+    }
+}
+
+module.exports = {
+    Prometheus
+};