From 537adab9211c172275067c011a39ccc68819df00 Mon Sep 17 00:00:00 2001
From: August Felso <77752049+amfelso@users.noreply.github.com>
Date: Fri, 6 Mar 2026 05:59:15 -0500
Subject: [PATCH 1/9] Attach proc directory

---
 helm/pi-agent/templates/daemonset.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/helm/pi-agent/templates/daemonset.yaml b/helm/pi-agent/templates/daemonset.yaml
index 2eeabf1..332381f 100644
--- a/helm/pi-agent/templates/daemonset.yaml
+++ b/helm/pi-agent/templates/daemonset.yaml
@@ -22,6 +22,9 @@ spec:
           - name: sysfs
             mountPath: /host/sys
             readOnly: true
+          - name: procfs
+            mountPath: /host/proc
+            readOnly: true
       tolerations:
       # Run on all nodes including control plane
       - operator: Exists
@@ -29,3 +32,6 @@ spec:
       - name: sysfs
         hostPath:
           path: /sys
+      - name: procfs
+        hostPath:
+          path: /proc

From 60a6e167330f35210319e7484ca6e4698423c843 Mon Sep 17 00:00:00 2001
From: August Felso <77752049+amfelso@users.noreply.github.com>
Date: Fri, 6 Mar 2026 06:18:28 -0500
Subject: [PATCH 2/9] Add temperature metric

---
 app/collectors/temperature.go          | 38 ++++++++++++++++++++++++++
 app/main.go                            | 13 +++++----
 helm/pi-agent/templates/daemonset.yaml |  3 ++
 3 files changed, 48 insertions(+), 6 deletions(-)
 create mode 100644 app/collectors/temperature.go

diff --git a/app/collectors/temperature.go b/app/collectors/temperature.go
new file mode 100644
index 0000000..e797a07
--- /dev/null
+++ b/app/collectors/temperature.go
@@ -0,0 +1,38 @@
+package collectors
+
+import (
+	"log"
+	"os"
+	"strconv"
+	"strings"
+)
+
+type Temperature struct{
+	fileName string
+}
+
+func NewTemperature(path string) *Temperature {
+	return &Temperature{fileName: path}
+}
+ 
+func (t *Temperature)Name() string {
+    return "temp_f"
+}
+
+func (t *Temperature)Collect() (float64, error) {
+	// Open the file
+	file, err := os.ReadFile(t.fileName)
+	if err != nil {
+		log.Printf("Error reading file: %s", err)
+		return 0.0, err 
+	}
+	
+	tempC, err := strconv.ParseInt(strings.TrimSpace(string(file)), 10, 64)
+	if err != nil {
+		return 0.0, err
+	}
+
+	// Calculate Fahrenheit
+	tempF := ((float64(tempC) / 1000.0) * (9.0 / 5.0)) + 32.0
+	return tempF, nil
+}
\ No newline at end of file
diff --git a/app/main.go b/app/main.go
index d52e1b7..e363b98 100644
--- a/app/main.go
+++ b/app/main.go
@@ -9,16 +9,17 @@ import (
 )
 
 func main() {
-	var seconds int
+	var schedule int
 
-	flag.IntVar(&seconds, "seconds", 300, "the time between metric collection cycles")
+	flag.IntVar(&schedule, "schedule", 300, "seconds between metric collection cycles")
 
 	flag.Parse()
-	log.Printf("Seconds: %d\n", seconds)
+	log.Printf("Schedule: %d seconds\n", schedule)
 
-	metrics := []collectors.Collector{collectors.NewCpu("/host/proc/stat"), collectors.NewMemory("/host/proc/meminfo")}
+	metrics := []collectors.Collector{collectors.NewCpu("/host/proc/stat"), collectors.NewMemory("/host/proc/meminfo"),
+									  collectors.NewTemperature("/host/sys/class/thermal/thermal_zone0/temp")}
 
-	ticker := time.NewTicker(time.Duration(seconds) * time.Second)
+	ticker := time.NewTicker(time.Duration(schedule) * time.Second)
 	for range ticker.C {
 		for _, c := range metrics {
 			val, err := c.Collect()
@@ -26,7 +27,7 @@ func main() {
 				log.Printf("Couldn't get metric value: %s\n", err)
 				continue
 			}
-			log.Printf("Found metric value: %.2f\n", val)
+			log.Printf("%s: %.2f\n", c.Name(), val)
 		}
 	}
 }
diff --git a/helm/pi-agent/templates/daemonset.yaml b/helm/pi-agent/templates/daemonset.yaml
index 332381f..40aa46e 100644
--- a/helm/pi-agent/templates/daemonset.yaml
+++ b/helm/pi-agent/templates/daemonset.yaml
@@ -18,6 +18,9 @@ spec:
         - name: {{ .Chart.Name }}
           image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
           imagePullPolicy: {{ .Values.image.pullPolicy }}
+          args:
+            - "--schedule"
+            - "{{ .Values.collector.schedule }}"
           volumeMounts:
           - name: sysfs
             mountPath: /host/sys

From e254b5c7c9128c384dc71735d8167ed8b710550b Mon Sep 17 00:00:00 2001
From: August Felso <77752049+amfelso@users.noreply.github.com>
Date: Fri, 6 Mar 2026 06:35:51 -0500
Subject: [PATCH 3/9] Add tests for temperature

---
 app/collectors/temperature_test.go | 84 ++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 app/collectors/temperature_test.go

diff --git a/app/collectors/temperature_test.go b/app/collectors/temperature_test.go
new file mode 100644
index 0000000..9164f83
--- /dev/null
+++ b/app/collectors/temperature_test.go
@@ -0,0 +1,84 @@
+package collectors
+
+import (
+	"os"
+	"testing"
+)
+
+func writeTempInfo(t *testing.T, content string) string {
+	t.Helper()
+	f, err := os.CreateTemp("", "sys-class-thermal-thermal_zone0-temp-*")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = os.Remove(f.Name()) })
+	if _, err := f.WriteString(content); err != nil {
+		t.Fatal(err)
+	}
+	if err := f.Close(); err != nil {
+		t.Fatal(err)
+	}
+	return f.Name()
+}
+
+func TestTempName(t *testing.T) {
+	tp := &Temperature{}
+	if tp.Name() != "temp_f" {
+		t.Errorf("expected name 'temp_f', got %s", tp.Name())
+	}
+}
+
+func TestTempCollect_ZeroVal(t *testing.T) {
+	// Celsius=0 → fahrenheight = 32.0
+	content := "00000\n"
+	path := writeTempInfo(t, content)
+	tp := &Temperature{fileName: path}
+
+	val, err := tp.Collect()
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if val != 32.0 {
+		t.Errorf("expected 32.0, got %.2f", val)
+	}
+}
+
+func TestTempCollect_PositiveVal(t *testing.T) {
+	// Celsius=50.634 → fahrenheight = 123.14
+	content := "50634\n"
+	path := writeTempInfo(t, content)
+	tp := &Temperature{fileName: path}
+
+	val, err := tp.Collect()
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if val < 123.14 || val > 123.15 {
+		t.Errorf("expected ~123.14, got %.4f", val)
+	}
+}
+
+func TestTempCollect_NegativeVal(t *testing.T) {
+	// Celsius=-6.666 → fahrenheight = 20.0
+	content := "-6666\n"
+	path := writeTempInfo(t, content)
+	tp := &Temperature{fileName: path}
+
+	val, err := tp.Collect()
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if val < 20.0 || val > 20.01 {
+		t.Errorf("expected ~20.0, got %.4f", val)
+	}
+}
+
+func TestTempCollect_EmptyFile(t *testing.T) {
+	path := writeTempInfo(t, "")
+	tp := &Temperature{fileName: path}
+
+	_, err := tp.Collect()
+	if err == nil {
+		t.Error("expected error for empty file, got nil")
+	}
+}
\ No newline at end of file

From b09ce60c4587c5821bcf8a989dec75d61a246c92 Mon Sep 17 00:00:00 2001
From: August Felso <77752049+amfelso@users.noreply.github.com>
Date: Fri, 6 Mar 2026 06:54:11 -0500
Subject: [PATCH 4/9] Mount rootfs

---
 helm/pi-agent/templates/daemonset.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/helm/pi-agent/templates/daemonset.yaml b/helm/pi-agent/templates/daemonset.yaml
index 40aa46e..7fe193a 100644
--- a/helm/pi-agent/templates/daemonset.yaml
+++ b/helm/pi-agent/templates/daemonset.yaml
@@ -28,6 +28,9 @@ spec:
           - name: procfs
             mountPath: /host/proc
             readOnly: true
+          - name: rootfs
+            mountPath: /host/root
+            readOnly: true
       tolerations:
       # Run on all nodes including control plane
       - operator: Exists
@@ -38,3 +41,6 @@ spec:
       - name: procfs
         hostPath:
           path: /proc
+      - name: rootfs
+        hostPath:
+          path: /

From d67d971eb369d7946951646e0d50ca48fef6cc4a Mon Sep 17 00:00:00 2001
From: August Felso <77752049+amfelso@users.noreply.github.com>
Date: Fri, 6 Mar 2026 06:57:18 -0500
Subject: [PATCH 5/9] Add disk metric

---
 app/collectors/disk.go | 29 +++++++++++++++++++++++++++++
 app/main.go            |  3 ++-
 2 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 app/collectors/disk.go

diff --git a/app/collectors/disk.go b/app/collectors/disk.go
new file mode 100644
index 0000000..01ba30d
--- /dev/null
+++ b/app/collectors/disk.go
@@ -0,0 +1,29 @@
+package collectors
+
+import (
+	"syscall"
+)
+
+type Disk struct{
+	path string
+}
+
+func NewDisk(path string) *Disk {
+	return &Disk{path: path}
+}
+ 
+func (d *Disk)Name() string {
+    return "disk"
+}
+
+func (d *Disk)Collect() (float64, error) {
+	// Call Statfs
+	var stat syscall.Statfs_t
+	err := syscall.Statfs(d.path, &stat)
+	if err != nil {
+		return 0.0, err
+	}
+
+	usagePercent := (1.0 - float64(stat.Bavail) / float64(stat.Blocks)) * 100.0
+	return usagePercent, nil
+}
\ No newline at end of file
diff --git a/app/main.go b/app/main.go
index e363b98..8519900 100644
--- a/app/main.go
+++ b/app/main.go
@@ -17,7 +17,8 @@ func main() {
 	log.Printf("Schedule: %d seconds\n", schedule)
 
 	metrics := []collectors.Collector{collectors.NewCpu("/host/proc/stat"), collectors.NewMemory("/host/proc/meminfo"),
-									  collectors.NewTemperature("/host/sys/class/thermal/thermal_zone0/temp")}
+		collectors.NewTemperature("/host/sys/class/thermal/thermal_zone0/temp"),
+		collectors.NewDisk("/host/root/")}
 
 	ticker := time.NewTicker(time.Duration(schedule) * time.Second)
 	for range ticker.C {

From eecf686e3dba0a8db312510271ba9a494e53ad8b Mon Sep 17 00:00:00 2001
From: August Felso <77752049+amfelso@users.noreply.github.com>
Date: Fri, 6 Mar 2026 06:57:39 -0500
Subject: [PATCH 6/9] Run gofmt

---
 app/collectors/cpu.go              | 30 +++++++++++++++---------------
 app/collectors/disk.go             | 14 +++++++-------
 app/collectors/memory.go           | 18 +++++++++---------
 app/collectors/temperature.go      | 16 ++++++++--------
 app/collectors/temperature_test.go |  2 +-
 5 files changed, 40 insertions(+), 40 deletions(-)

diff --git a/app/collectors/cpu.go b/app/collectors/cpu.go
index 27a0553..adc4a01 100644
--- a/app/collectors/cpu.go
+++ b/app/collectors/cpu.go
@@ -9,26 +9,26 @@ import (
 	"strings"
 )
 
-type Cpu struct{
+type Cpu struct {
 	prevIdle  uint64
-    prevTotal uint64
-	fileName string
+	prevTotal uint64
+	fileName  string
 }
 
 func NewCpu(path string) *Cpu {
 	return &Cpu{fileName: path}
 }
- 
-func (c *Cpu)Name() string {
-    return "cpu"
+
+func (c *Cpu) Name() string {
+	return "cpu"
 }
 
-func (c *Cpu)Collect() (float64, error) {
+func (c *Cpu) Collect() (float64, error) {
 	// Open the file
 	file, err := os.Open(c.fileName)
 	if err != nil {
 		log.Printf("Error opening file: %s", err)
-		return 0.0, err 
+		return 0.0, err
 	}
 
 	// Ensure the file is closed the the function exits
@@ -52,17 +52,17 @@ func (c *Cpu)Collect() (float64, error) {
 	}
 
 	// Calculate idleDelta
-	idleDelta := currentIdle  - c.prevIdle
+	idleDelta := currentIdle - c.prevIdle
 
 	// calculate currentTotal
-    var currentTotal uint64
-    for _, stat := range stats {
+	var currentTotal uint64
+	for _, stat := range stats {
 		stat, err := strconv.ParseUint(stat, 10, 64)
 		if err != nil {
 			return 0.0, err
 		}
-        currentTotal += uint64(stat)
-    }
+		currentTotal += uint64(stat)
+	}
 
 	// values for first run
 	if c.prevTotal == 0 {
@@ -75,11 +75,11 @@ func (c *Cpu)Collect() (float64, error) {
 	totalDelta := currentTotal - c.prevTotal
 
 	// Usage Percent = (1 - idleDelta/totalDelta) * 100
-	usagePercent := (1.0 - float64(idleDelta)/float64(totalDelta))* 100
+	usagePercent := (1.0 - float64(idleDelta)/float64(totalDelta)) * 100
 
 	// Save current readings
 	c.prevIdle = currentIdle
 	c.prevTotal = currentTotal
 
 	return usagePercent, nil
-}
\ No newline at end of file
+}
diff --git a/app/collectors/disk.go b/app/collectors/disk.go
index 01ba30d..9cf0fb2 100644
--- a/app/collectors/disk.go
+++ b/app/collectors/disk.go
@@ -4,19 +4,19 @@ import (
 	"syscall"
 )
 
-type Disk struct{
+type Disk struct {
 	path string
 }
 
 func NewDisk(path string) *Disk {
 	return &Disk{path: path}
 }
- 
-func (d *Disk)Name() string {
-    return "disk"
+
+func (d *Disk) Name() string {
+	return "disk"
 }
 
-func (d *Disk)Collect() (float64, error) {
+func (d *Disk) Collect() (float64, error) {
 	// Call Statfs
 	var stat syscall.Statfs_t
 	err := syscall.Statfs(d.path, &stat)
@@ -24,6 +24,6 @@ func (d *Disk)Collect() (float64, error) {
 		return 0.0, err
 	}
 
-	usagePercent := (1.0 - float64(stat.Bavail) / float64(stat.Blocks)) * 100.0
+	usagePercent := (1.0 - float64(stat.Bavail)/float64(stat.Blocks)) * 100.0
 	return usagePercent, nil
-}
\ No newline at end of file
+}
diff --git a/app/collectors/memory.go b/app/collectors/memory.go
index 60f0968..25bfcd0 100644
--- a/app/collectors/memory.go
+++ b/app/collectors/memory.go
@@ -9,24 +9,24 @@ import (
 	"strings"
 )
 
-type Memory struct{
+type Memory struct {
 	fileName string
 }
 
 func NewMemory(path string) *Memory {
 	return &Memory{fileName: path}
 }
- 
-func (m *Memory)Name() string {
-    return "memory"
+
+func (m *Memory) Name() string {
+	return "memory"
 }
 
-func (m *Memory)Collect() (float64, error) {
+func (m *Memory) Collect() (float64, error) {
 	// Open the file
 	file, err := os.Open(m.fileName)
 	if err != nil {
 		log.Printf("Error opening file: %s", err)
-		return 0.0, err 
+		return 0.0, err
 	}
 
 	// Ensure the file is closed the the function exits
@@ -34,7 +34,7 @@ func (m *Memory)Collect() (float64, error) {
 
 	// Create a new Scanner for the file
 	scanner := bufio.NewScanner(file)
-	
+
 	// Get memTotal from line 0
 	if !scanner.Scan() {
 		if err := scanner.Err(); err != nil {
@@ -68,6 +68,6 @@ func (m *Memory)Collect() (float64, error) {
 	}
 
 	// Calculate usagePercent
-	usagePercent := float64(memTotal - memAvailable) / float64(memTotal) * 100
+	usagePercent := float64(memTotal-memAvailable) / float64(memTotal) * 100
 	return usagePercent, nil
-}
\ No newline at end of file
+}
diff --git a/app/collectors/temperature.go b/app/collectors/temperature.go
index e797a07..228fd13 100644
--- a/app/collectors/temperature.go
+++ b/app/collectors/temperature.go
@@ -7,26 +7,26 @@ import (
 	"strings"
 )
 
-type Temperature struct{
+type Temperature struct {
 	fileName string
 }
 
 func NewTemperature(path string) *Temperature {
 	return &Temperature{fileName: path}
 }
- 
-func (t *Temperature)Name() string {
-    return "temp_f"
+
+func (t *Temperature) Name() string {
+	return "temp_f"
 }
 
-func (t *Temperature)Collect() (float64, error) {
+func (t *Temperature) Collect() (float64, error) {
 	// Open the file
 	file, err := os.ReadFile(t.fileName)
 	if err != nil {
 		log.Printf("Error reading file: %s", err)
-		return 0.0, err 
+		return 0.0, err
 	}
-	
+
 	tempC, err := strconv.ParseInt(strings.TrimSpace(string(file)), 10, 64)
 	if err != nil {
 		return 0.0, err
@@ -35,4 +35,4 @@ func (t *Temperature)Collect() (float64, error) {
 	// Calculate Fahrenheit
 	tempF := ((float64(tempC) / 1000.0) * (9.0 / 5.0)) + 32.0
 	return tempF, nil
-}
\ No newline at end of file
+}
diff --git a/app/collectors/temperature_test.go b/app/collectors/temperature_test.go
index 9164f83..61d4c66 100644
--- a/app/collectors/temperature_test.go
+++ b/app/collectors/temperature_test.go
@@ -81,4 +81,4 @@ func TestTempCollect_EmptyFile(t *testing.T) {
 	if err == nil {
 		t.Error("expected error for empty file, got nil")
 	}
-}
\ No newline at end of file
+}

From 6f483130fa6fc6129065fff357436273d35649a4 Mon Sep 17 00:00:00 2001
From: August Felso <77752049+amfelso@users.noreply.github.com>
Date: Fri, 6 Mar 2026 07:00:45 -0500
Subject: [PATCH 7/9] Add lint check for gofmt

---
 Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Makefile b/Makefile
index b00f975..de6cd9a 100644
--- a/Makefile
+++ b/Makefile
@@ -29,6 +29,7 @@ install-tools:
 
 .PHONY: lint
 lint:
+	@if [ -n "$$(cd app && gofmt -l .)" ]; then echo "gofmt: run 'gofmt -w app/'"; exit 1; fi
 	@cd app && golangci-lint run ./...;
 	@helm lint helm/pi-agent;
 	@hadolint docker/Dockerfile;

From f876aeb3e2476ac65cd9f75262ef155af146f6d1 Mon Sep 17 00:00:00 2001
From: August Felso <77752049+amfelso@users.noreply.github.com>
Date: Fri, 6 Mar 2026 07:07:58 -0500
Subject: [PATCH 8/9] Add disk test.go

---
 app/collectors/disk_test.go | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 app/collectors/disk_test.go

diff --git a/app/collectors/disk_test.go b/app/collectors/disk_test.go
new file mode 100644
index 0000000..7d632dd
--- /dev/null
+++ b/app/collectors/disk_test.go
@@ -0,0 +1,29 @@
+package collectors
+
+import "testing"
+
+func TestDiskName(t *testing.T) {
+	d := &Disk{}
+	if d.Name() != "disk" {
+		t.Errorf("expected name 'disk', got %s", d.Name())
+	}
+}
+
+func TestDiskCollect_ReturnsValidPercent(t *testing.T) {
+	d := &Disk{path: "/tmp"}
+	val, err := d.Collect()
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if val < 0 || val > 100 {
+		t.Errorf("expected value between 0 and 100, got %.2f", val)
+	}
+}
+
+func TestDiskCollect_InvalidPath(t *testing.T) {
+	d := &Disk{path: "/nonexistent/path"}
+	_, err := d.Collect()
+	if err == nil {
+		t.Error("expected error for invalid path, got nil")
+	}
+}

From 1a9f7c26908f8bc286f1e2e5329885202ec3f590 Mon Sep 17 00:00:00 2001
From: August Felso <77752049+amfelso@users.noreply.github.com>
Date: Fri, 6 Mar 2026 07:11:31 -0500
Subject: [PATCH 9/9] Add gofmt check in CI

---
 .github/workflows/develop.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/.github/workflows/develop.yaml b/.github/workflows/develop.yaml
index 5098cf7..7bc2f0f 100644
--- a/.github/workflows/develop.yaml
+++ b/.github/workflows/develop.yaml
@@ -16,6 +16,12 @@ jobs:
       - uses: hadolint/hadolint-action@v3.1.0
         with:
           dockerfile: docker/Dockerfile
+      - name: Check gofmt
+        run: |
+          if [ -n "$(cd app && gofmt -l .)" ]; then
+            echo "gofmt: run 'gofmt -w app/'"
+            exit 1
+          fi
       - uses: golangci/golangci-lint-action@v6
         with:
           working-directory: app