fix(docker): normalize container CPU usage

.github/pull_request_template.md

@@ -4,14 +4,14 @@
   <h3>Homarr</h3>
 </div>
 
-**Thank you for your contribution. Please ensure that your pull request meets the following requirements:**
+**Thank you for your contribution. Please ensure that your pull request meets the following pull request:**
 
-- [ ] Relevant checks pass without warnings or errors
-- [ ] Pull request targets the intended base branch (`dev` by default; `release/v2` for v2 release work)
+- [ ] Builds without warnings or errors (`pnpm build`, autofix with `pnpm format:fix`)
+- [ ] Pull request targets `dev` branch
 - [ ] Commits follow the [conventional commits guideline](https://www.conventionalcommits.org/en/v1.0.0/)
-- [ ] No shorthand variable names are used (for example, `x`, `y`, `i`, or abbreviations)
-- [ ] User-facing changes include matching documentation updates under `apps/docs`
-- [ ] When using AI, no temporary files are checked in and the code style follows the rest of the project
+- [ ] No shorthand variable names are used (eg. `x`, `y`, `i` or any abbrevation)
+- [ ] Documentation is up to date. Create a pull request [here](https://github.com/homarr-labs/documentation/).
+- [ ] When using AI; No temp files are checked in, the code style follows the rest of the project
 
 **When contributing a new integration or widget:**
 

packages/request-handler/src/docker.ts

@@ -481,13 +481,14 @@ export function calculateCpuUsage(stats: ContainerStats): number {
     return 0;
   }
 
-  const numberOfCpus = stats.cpu_stats.online_cpus;
-  const usage = stats.cpu_stats.system_cpu_usage;
-  if (!usage || usage === 0) {
+  const cpuDelta = stats.cpu_stats.cpu_usage.total_usage - (stats.precpu_stats?.cpu_usage?.total_usage ?? 0);
+  const systemDelta = (stats.cpu_stats.system_cpu_usage ?? 0) - (stats.precpu_stats?.system_cpu_usage ?? 0);
+
+  if (systemDelta <= 0 || cpuDelta < 0) {
     return 0;
   }
 
-  return (stats.cpu_stats.cpu_usage.total_usage / usage) * numberOfCpus * 100;
+  return (cpuDelta / systemDelta) * 100;
 }
 
 export function calculateMemoryUsage(stats: ContainerStats): number {

packages/request-handler/src/test/docker.spec.ts

@@ -72,16 +72,16 @@ describe("calculateCpuUsage", () => {
     const stats = createStats({
       cpu_stats: { online_cpus: 4, cpu_usage: { total_usage: 2000 }, system_cpu_usage: 10000 },
     });
-    // (2000 / 10000) * 4 * 100 = 80
-    expect(calculateCpuUsage(stats)).toBe(80);
+    // (2000 / 10000) * 100 = 20
+    expect(calculateCpuUsage(stats)).toBe(20);
   });
 
   test("should handle fractional CPU usage", () => {
     const stats = createStats({
       cpu_stats: { online_cpus: 2, cpu_usage: { total_usage: 500 }, system_cpu_usage: 100000 },
     });
-    // (500 / 100000) * 2 * 100 = 1
-    expect(calculateCpuUsage(stats)).toBe(1);
+    // (500 / 100000) * 100 = 0.5
+    expect(calculateCpuUsage(stats)).toBe(0.5);
   });
 });