docs/plans/cert-monitoring.md

@@ -0,0 +1,72 @@
+# Certificate Monitoring Plan
+
+## Summary
+
+This document describes the removal of labmon certificate monitoring and outlines future needs for certificate monitoring in the homelab.
+
+## What Was Removed
+
+### labmon Service
+
+The `labmon` service was a custom Go application that provided:
+
+1. **StepMonitor**: Monitoring for step-ca (Smallstep CA) certificate provisioning and health
+2. **TLSConnectionMonitor**: Periodic TLS connection checks to verify certificate validity and expiration
+
+The service exposed Prometheus metrics at `:9969` including:
+- `labmon_tlsconmon_certificate_seconds_left` - Time until certificate expiration
+- `labmon_tlsconmon_certificate_check_error` - Whether the TLS check failed
+- `labmon_stepmon_certificate_seconds_left` - Step-CA internal certificate expiration
+
+### Affected Files
+
+- `hosts/monitoring01/configuration.nix` - Removed labmon configuration block
+- `services/monitoring/prometheus.nix` - Removed labmon scrape target
+- `services/monitoring/rules.yml` - Removed `certificate_rules` alert group
+- `services/monitoring/alloy.nix` - Deleted (was only used for labmon profiling)
+- `services/monitoring/default.nix` - Removed alloy.nix import
+
+### Removed Alerts
+
+- `certificate_expiring_soon` - Warned when any monitored TLS cert had < 24h validity
+- `step_ca_serving_cert_expiring` - Critical alert for step-ca's own serving certificate
+- `certificate_check_error` - Warned when TLS connection check failed
+- `step_ca_certificate_expiring` - Critical alert for step-ca issued certificates
+
+## Why It Was Removed
+
+1. **step-ca decommissioned**: The primary monitoring target (step-ca) is no longer in use
+2. **Outdated codebase**: labmon was a custom tool that required maintenance
+3. **Limited value**: With ACME auto-renewal, certificates should renew automatically
+
+## Current State
+
+ACME certificates are now issued by OpenBao PKI at `vault.home.2rjus.net:8200`. The ACME protocol handles automatic renewal, and certificates are typically renewed well before expiration.
+
+## Future Needs
+
+While ACME handles renewal automatically, we should consider monitoring for:
+
+1. **ACME renewal failures**: Alert when a certificate fails to renew
+   - Could monitor ACME client logs (via Loki queries)
+   - Could check certificate file modification times
+
+2. **Certificate expiration as backup**: Even with auto-renewal, a last-resort alert for certificates approaching expiration would catch renewal failures
+
+3. **Certificate transparency**: Monitor for unexpected certificate issuance
+
+### Potential Solutions
+
+1. **Prometheus blackbox_exporter**: Can probe TLS endpoints and export certificate expiration metrics
+   - `probe_ssl_earliest_cert_expiry` metric
+   - Already a standard tool, well-maintained
+
+2. **Custom Loki alerting**: Query ACME service logs for renewal failures
+   - Works with existing infrastructure
+   - No additional services needed
+
+3. **Node-exporter textfile collector**: Script that checks local certificate files and writes expiration metrics
+
+## Status
+
+**Not yet implemented.** This document serves as a placeholder for future work on certificate monitoring.

hosts/monitoring01/configuration.nix

@@ -100,61 +100,6 @@
     ];
   };
 
-  labmon = {
-    enable = true;
-
-    settings = {
-      ListenAddr = ":9969";
-      Profiling = true;
-      StepMonitors = [
-        {
-          Enabled = true;
-          BaseURL = "https://ca.home.2rjus.net";
-          RootID = "3381bda8015a86b9a3cd1851439d1091890a79005e0f1f7c4301fe4bccc29d80";
-        }
-      ];
-
-      TLSConnectionMonitors = [
-        {
-          Enabled = true;
-          Address = "ca.home.2rjus.net:443";
-          Verify = true;
-          Duration = "12h";
-        }
-        {
-          Enabled = true;
-          Address = "jelly.home.2rjus.net:443";
-          Verify = true;
-          Duration = "12h";
-        }
-        {
-          Enabled = true;
-          Address = "grafana.home.2rjus.net:443";
-          Verify = true;
-          Duration = "12h";
-        }
-        {
-          Enabled = true;
-          Address = "prometheus.home.2rjus.net:443";
-          Verify = true;
-          Duration = "12h";
-        }
-        {
-          Enabled = true;
-          Address = "alertmanager.home.2rjus.net:443";
-          Verify = true;
-          Duration = "12h";
-        }
-        {
-          Enabled = true;
-          Address = "pyroscope.home.2rjus.net:443";
-          Verify = true;
-          Duration = "12h";
-        }
-      ];
-    };
-  };
-
   # Open ports in the firewall.
   # networking.firewall.allowedTCPPorts = [ ... ];
   # networking.firewall.allowedUDPPorts = [ ... ];

services/http-proxy/proxy.nix

@@ -5,7 +5,7 @@
     package = pkgs.unstable.caddy;
     configFile = pkgs.writeText "Caddyfile" ''
       {
-        acme_ca https://ca.home.2rjus.net/acme/acme/directory
+        acme_ca https://vault.home.2rjus.net:8200/v1/pki_int/acme/directory
 
         metrics {
           per_host

services/monitoring/alloy.nix

@@ -1,41 +0,0 @@
-{ ... }:
-{
-  services.alloy = {
-    enable = true;
-  };
-
-  environment.etc."alloy/config.alloy" = {
-    enable = true;
-    mode = "0644";
-    text = ''
-      pyroscope.write "local_pyroscope" {
-        endpoint {
-          url = "http://localhost:4040"
-        }
-      }
-
-      pyroscope.scrape "labmon" {
-        targets    = [{"__address__" = "localhost:9969", "service_name" = "labmon"}]
-        forward_to = [pyroscope.write.local_pyroscope.receiver]
-
-        profiling_config {
-          profile.process_cpu {
-            enabled = true
-          }
-          profile.memory {
-            enabled = true
-          }
-          profile.mutex {
-            enabled = true
-          }
-          profile.block {
-            enabled = true
-          }
-          profile.goroutine {
-            enabled = true
-          }
-        }
-      }
-    '';
-  };
-}

services/monitoring/default.nix

@@ -7,7 +7,6 @@
     ./pve.nix
     ./alerttonotify.nix
     ./pyroscope.nix
-    ./alloy.nix
     ./tempo.nix
   ];
 }

services/monitoring/prometheus.nix

@@ -178,14 +178,6 @@ in
           }
         ];
       }
-      {
-        job_name = "labmon";
-        static_configs = [
-          {
-            targets = [ "monitoring01.home.2rjus.net:9969" ];
-          }
-        ];
-      }
       # TODO: nix-cache_caddy can't be auto-generated because the cert is issued
       # for nix-cache.home.2rjus.net (service CNAME), not nix-cache01 (hostname).
       # Consider adding a target override to homelab.monitoring.scrapeTargets.

services/monitoring/rules.yml

@@ -338,40 +338,6 @@ groups:
         annotations:
           summary: "Pyroscope service not running on {{ $labels.instance }}"
           description: "Pyroscope service not running on {{ $labels.instance }}"
-  - name: certificate_rules
-    rules:
-      - alert: certificate_expiring_soon
-        expr: labmon_tlsconmon_certificate_seconds_left{address!="ca.home.2rjus.net:443"} < 86400
-        for: 5m
-        labels:
-          severity: warning
-        annotations:
-          summary: "TLS certificate expiring soon for {{ $labels.instance }}"
-          description: "TLS certificate for {{ $labels.address }} is expiring within 24 hours."
-      - alert: step_ca_serving_cert_expiring
-        expr: labmon_tlsconmon_certificate_seconds_left{address="ca.home.2rjus.net:443"} < 3600
-        for: 5m
-        labels:
-          severity: critical
-        annotations:
-          summary: "Step-CA serving certificate expiring"
-          description: "The step-ca serving certificate (24h auto-renewed) has less than 1 hour of validity left. Renewal may have failed."
-      - alert: certificate_check_error
-        expr: labmon_tlsconmon_certificate_check_error == 1
-        for: 5m
-        labels:
-          severity: warning
-        annotations:
-          summary: "Error checking certificate for {{ $labels.address }}"
-          description: "Certificate check is failing for {{ $labels.address }} on {{ $labels.instance }}."
-      - alert: step_ca_certificate_expiring
-        expr: labmon_stepmon_certificate_seconds_left < 3600
-        for: 5m
-        labels:
-          severity: critical
-        annotations:
-          summary: "Step-CA certificate expiring for {{ $labels.instance }}"
-          description: "Step-CA certificate is expiring within 1 hour on {{ $labels.instance }}."
   - name: proxmox_rules
     rules:
       - alert: pve_node_down

services/nix-cache/proxy.nix

@@ -5,7 +5,7 @@
     package = pkgs.unstable.caddy;
     configFile = pkgs.writeText "Caddyfile" ''
       {
-        acme_ca https://ca.home.2rjus.net/acme/acme/directory
+        acme_ca https://vault.home.2rjus.net:8200/v1/pki_int/acme/directory
         metrics
       }
 

system/acme.nix

@@ -3,7 +3,7 @@
   security.acme = {
     acceptTerms = true;
     defaults = {
-      server = "https://ca.home.2rjus.net/acme/acme/directory";
+      server = "https://vault.home.2rjus.net:8200/v1/pki_int/acme/directory";
       email = "root@home.2rjus.net";
       dnsPropagationCheck = false;
     };