Initial Beach: homelab control panel

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/beach/host.go

@@ -0,0 +1,129 @@
+package beach
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// Host is the machine Beach runs on.
+type Host struct {
+	Hostname  string       `json:"hostname"`
+	Uptime    float64      `json:"uptimeSeconds"`
+	Load      [3]float64   `json:"load"`
+	CPUPct    float64      `json:"cpuPct"`
+	CPUs      int          `json:"cpus"`
+	MemTotal  uint64       `json:"memTotal"`
+	MemUsed   uint64       `json:"memUsed"`
+	SwapTotal uint64       `json:"swapTotal"`
+	SwapUsed  uint64       `json:"swapUsed"`
+	Disks     []Filesystem `json:"filesystems"`
+	Supported bool         `json:"supported"`
+}
+
+type Filesystem struct {
+	Mount string `json:"mount"`
+	Total uint64 `json:"total"`
+	Used  uint64 `json:"used"`
+}
+
+// cpuTimes is the aggregate line of /proc/stat.
+type cpuTimes struct{ busy, total uint64 }
+
+func parseCPU(stat string) (cpuTimes, error) {
+	for _, line := range strings.Split(stat, "\n") {
+		f := strings.Fields(line)
+		if len(f) < 5 || f[0] != "cpu" {
+			continue
+		}
+		var v []uint64
+		for _, s := range f[1:] {
+			n, err := strconv.ParseUint(s, 10, 64)
+			if err != nil {
+				return cpuTimes{}, err
+			}
+			v = append(v, n)
+		}
+		var total uint64
+		for i, n := range v {
+			if i < 8 { // guest times are already counted in user/nice
+				total += n
+			}
+		}
+		idle := v[3]
+		if len(v) > 4 {
+			idle += v[4] // iowait
+		}
+		return cpuTimes{busy: total - idle, total: total}, nil
+	}
+	return cpuTimes{}, fmt.Errorf("no cpu line")
+}
+
+// cpuPct is the busy share between two samples.
+func cpuPct(a, b cpuTimes) float64 {
+	if b.total <= a.total || b.busy < a.busy {
+		return 0
+	}
+	return float64(b.busy-a.busy) / float64(b.total-a.total) * 100
+}
+
+func parseMeminfo(s string) (total, used, swapTotal, swapUsed uint64) {
+	kb := map[string]uint64{}
+	for _, line := range strings.Split(s, "\n") {
+		f := strings.Fields(line)
+		if len(f) >= 2 {
+			n, _ := strconv.ParseUint(f[1], 10, 64)
+			kb[strings.TrimSuffix(f[0], ":")] = n * 1024
+		}
+	}
+	total = kb["MemTotal"]
+	avail, ok := kb["MemAvailable"]
+	if !ok {
+		avail = kb["MemFree"] + kb["Buffers"] + kb["Cached"]
+	}
+	if avail <= total {
+		used = total - avail
+	}
+	swapTotal = kb["SwapTotal"]
+	if kb["SwapFree"] <= swapTotal {
+		swapUsed = swapTotal - kb["SwapFree"]
+	}
+	return
+}
+
+func parseLoad(s string) (l [3]float64) {
+	f := strings.Fields(s)
+	for i := 0; i < 3 && i < len(f); i++ {
+		l[i], _ = strconv.ParseFloat(f[i], 64)
+	}
+	return
+}
+
+func parseUptime(s string) float64 {
+	f := strings.Fields(s)
+	if len(f) == 0 {
+		return 0
+	}
+	v, _ := strconv.ParseFloat(f[0], 64)
+	return v
+}
+
+// realMounts picks the mounts worth showing from /proc/mounts: real block or
+// ZFS filesystems, once per device, without Docker's own overlay mounts.
+func realMounts(mounts string) []string {
+	ok := map[string]bool{"ext4": true, "xfs": true, "btrfs": true, "zfs": true, "ext3": true, "f2fs": true, "vfat": true, "ntfs": true, "ntfs3": true, "exfat": true}
+	seen := map[string]bool{}
+	var out []string
+	for _, line := range strings.Split(mounts, "\n") {
+		f := strings.Fields(line)
+		if len(f) < 3 || !ok[f[2]] || seen[f[0]] {
+			continue
+		}
+		if strings.HasPrefix(f[1], "/var/lib/docker") || strings.HasPrefix(f[1], "/proc") || strings.HasPrefix(f[1], "/sys") {
+			continue
+		}
+		seen[f[0]] = true
+		out = append(out, f[1])
+	}
+	return out
+}