config graphs to show

README.md

@@ -36,7 +36,7 @@ The executable application files are installed under
 separate.
 
 Edit `/opt/cheap_system_monitor/monitor.conf` to choose network interfaces,
-mountpoints, and the graph directory. For example, use
+mountpoints, graphs, and the graph directory. For example, use
 `mountpoints = /, /boot/firmware, /mnt/data` to monitor two additional disks;
 every configured path must be mounted and accessible.
 Restarting is unnecessary after configuration changes—the next timer runs use
@@ -44,6 +44,18 @@ the new values. If the RRD has already been created, do not change the order of
 mountpoints unless you intentionally want the historical graph labels to refer
 to different disks.
 
+Use the `graphs` setting to choose which graphs are generated and shown, and
+to set their dashboard order. Available names are `load`, `cpu`, `thermal`,
+`trouble`, `network`, `disk`, `storage-health`, and `uptime`. For a virtual
+machine where temperature is not meaningful, for example:
+
+```ini
+graphs = load, cpu, trouble, network, disk, storage-health, uptime
+```
+
+Omitting a graph does not disable collection of its underlying metrics. This
+keeps the RRD schema consistent if the graph is enabled later.
+
 The generated PNG files and four responsive, auto-refreshing dashboard pages
 are placed in `/var/www/html/system-monitor` by default. `index.html` shows
 the last 3 hours and links to the 1-day, 2-week, and 1-year pages.

cheap-system-monitor.conf.example

@@ -11,3 +11,8 @@ interfaces = auto
 
 # CPU percentages are measured over this interval each minute.
 cpu_sample_seconds = 1.0
+
+# Graphs to generate and show, in dashboard order. Available names:
+# load, cpu, thermal, trouble, network, disk, storage-health, uptime
+# For example, omit "thermal" on a virtual machine.
+graphs = load, cpu, thermal, trouble, network, disk, storage-health, uptime

generate_graphs.py

@@ -13,6 +13,10 @@ import subprocess
 PERIODS = {"3hours": "3h", "1day": "1d", "2weeks": "2w", "1year": "1y"}
 COLORS = ["#2563EB", "#DC2626", "#16A34A", "#9333EA"]
 LOAD_COLORS = ["#FACC15", "#F59E0B", "#DC2626"]  # bottom to top
+DEFAULT_GRAPHS = (
+    "load", "cpu", "thermal", "trouble", "network", "disk",
+    "storage-health", "uptime",
+)
 
 
 def graph(output: Path, rrd: Path, start: str, title: str, unit: str,
@@ -107,7 +111,7 @@ def main() -> None:
     mounts = [item.strip() for item in config["mountpoints"].split(",") if item.strip()]
     if not mounts or mounts[0] != "/":
         mounts.insert(0, "/")
-    definitions = [
+    all_definitions = [
         ("load", "Processor load", "load", [("load15", "15 minutes", "AVERAGE"), ("load5", "5 minutes", "AVERAGE"), ("load1", "1 minute", "AVERAGE")], False, True, False, False, False, False),
         ("cpu", "CPU usage", "%", [("cpu_user", "user", "AVERAGE"), ("cpu_system", "system", "AVERAGE"), ("cpu_nice", "nice", "AVERAGE"), ("io_wait", "I/O wait", "AVERAGE")], False, True, False, False, False, False),
         ("thermal", "CPU temperature and throttling", "°C", [("temperature", "temperature", "AVERAGE"), ("throttled", "throttled", "MAX")], False, False, False, False, True, False),
@@ -117,6 +121,23 @@ def main() -> None:
         ("storage-health", "Storage operational health", "0–10", [(f"health_{'root' if i == 0 else i}", mount, "MIN") for i, mount in enumerate(mounts)], False, False, False, False, False, False),
         ("uptime", "System uptime", "days", [("uptime", "uptime", "AVERAGE")], False, False, False, False, False, False),
     ]
+    configured_graphs = [
+        item.strip()
+        for item in config.get("graphs", ",".join(DEFAULT_GRAPHS)).split(",")
+        if item.strip()
+    ]
+    if not configured_graphs:
+        raise SystemExit("At least one graph must be configured in 'graphs'")
+    definitions_by_name = {definition[0]: definition for definition in all_definitions}
+    unknown = [name for name in configured_graphs if name not in definitions_by_name]
+    if unknown:
+        available = ", ".join(DEFAULT_GRAPHS)
+        raise SystemExit(
+            f"Unknown graph name(s): {', '.join(unknown)}. Available: {available}"
+        )
+    if len(configured_graphs) != len(set(configured_graphs)):
+        raise SystemExit("Graph names in 'graphs' must not be repeated")
+    definitions = [definitions_by_name[name] for name in configured_graphs]
     for period_name, start in PERIODS.items():
         for filename, title, unit, series, logarithmic, stacked, disk_memory, network_mixed, thermal_mixed, trouble_mixed in definitions:
             graph(output_dir / f"{filename}-{period_name}.png", rrd, start,