From b53456dad8c3cc82ca05e6f368679d415071d171 Mon Sep 17 00:00:00 2001
From: Gilles Soulier <gilles@maison43>
Date: Fri, 22 May 2026 11:36:51 +0200
Subject: [PATCH] feat(agent): collecte SMART via smartctl -j

---
 agent/src/metrics/smart.rs | 93 ++++++++++++++++++++++++++++++++++++--
 agent/tests/smart_test.rs  | 45 ++++++++++++++++++
 2 files changed, 134 insertions(+), 4 deletions(-)
 create mode 100644 agent/tests/smart_test.rs

diff --git a/agent/src/metrics/smart.rs b/agent/src/metrics/smart.rs
index da46d1e..e6e7fad 100644
--- a/agent/src/metrics/smart.rs
+++ b/agent/src/metrics/smart.rs
@@ -1,13 +1,98 @@
+use serde::Deserialize;
 use crate::payload::SmartMetrics;
 
-pub fn is_available() -> bool {
-    false
+#[derive(Deserialize)]
+struct SmartJson {
+    smart_status: SmartStatus,
+    temperature: Option<SmartTemp>,
+    ata_smart_attributes: Option<SmartAttrs>,
+    nvme_smart_health_information_log: Option<NvmeHealth>,
 }
 
-pub fn parse_json(_: &str) -> Result<SmartMetrics, serde_json::Error> {
-    serde_json::from_str("null")
+#[derive(Deserialize)]
+struct SmartStatus { passed: bool }
+
+#[derive(Deserialize)]
+struct SmartTemp { current: i64 }
+
+#[derive(Deserialize)]
+struct SmartAttrs { table: Vec<SmartAttr> }
+
+#[derive(Deserialize)]
+struct SmartAttr {
+    id: u8,
+    raw: SmartAttrRaw,
+    value: Option<i64>,
+}
+
+#[derive(Deserialize)]
+struct SmartAttrRaw { value: i64 }
+
+#[derive(Deserialize)]
+struct NvmeHealth {
+    percentage_used: Option<i64>,
+    temperature: Option<i64>,
+}
+
+pub fn is_available() -> bool {
+    std::process::Command::new("which")
+        .arg("smartctl")
+        .output()
+        .map(|o| o.status.success())
+        .unwrap_or(false)
+}
+
+pub fn parse_json(json: &str) -> Result<SmartMetrics, serde_json::Error> {
+    let s: SmartJson = serde_json::from_str(json)?;
+
+    let temperature = s.temperature.as_ref().map(|t| t.current)
+        .or_else(|| s.nvme_smart_health_information_log.as_ref()?.temperature);
+
+    let mut reallocated = None;
+    let mut power_hours = None;
+    let mut wear = None;
+
+    if let Some(attrs) = &s.ata_smart_attributes {
+        for attr in &attrs.table {
+            match attr.id {
+                5   => reallocated = Some(attr.raw.value),
+                9   => power_hours = Some(attr.raw.value),
+                177 => wear = attr.value,
+                _   => {}
+            }
+        }
+    }
+
+    if wear.is_none() {
+        if let Some(nvme) = &s.nvme_smart_health_information_log {
+            if let Some(pct) = nvme.percentage_used {
+                wear = Some(100 - pct);
+            }
+        }
+    }
+
+    Ok(SmartMetrics {
+        passed: s.smart_status.passed,
+        temperature,
+        reallocated_sectors: reallocated,
+        power_on_hours: power_hours,
+        wear_level: wear,
+    })
 }
 
 pub fn collect() -> Option<SmartMetrics> {
+    if !is_available() {
+        return None;
+    }
+    for dev in &["/dev/sda", "/dev/nvme0"] {
+        let output = std::process::Command::new("smartctl")
+            .args(["-j", dev])
+            .output()
+            .ok()?;
+        let json = String::from_utf8_lossy(&output.stdout);
+        if let Ok(metrics) = parse_json(&json) {
+            return Some(metrics);
+        }
+    }
     None
 }
diff --git a/agent/tests/smart_test.rs b/agent/tests/smart_test.rs
new file mode 100644
index 0000000..cfcfbf4
--- /dev/null
+++ b/agent/tests/smart_test.rs
@@ -0,0 +1,45 @@
+use nanometrics_agent::metrics::smart;
+
+const SMART_JSON_OK: &str = r#"{
+  "smart_status": {"passed": true},
+  "temperature": {"current": 34},
+  "ata_smart_attributes": {
+    "table": [
+      {"id": 5,   "name": "Reallocated_Sector_Ct", "raw": {"value": 0},    "value": 200},
+      {"id": 9,   "name": "Power_On_Hours",         "raw": {"value": 4213}, "value": 77},
+      {"id": 177, "name": "Wear_Leveling_Count",    "raw": {"value": 0},    "value": 98}
+    ]
+  }
+}"#;
+
+#[test]
+fn test_parse_smart_json_ok() {
+    let result = smart::parse_json(SMART_JSON_OK).unwrap();
+    assert!(result.passed);
+    assert_eq!(result.temperature, Some(34));
+    assert_eq!(result.reallocated_sectors, Some(0));
+    assert_eq!(result.power_on_hours, Some(4213));
+    assert_eq!(result.wear_level, Some(98));
+}
+
+const SMART_JSON_FAIL: &str = r#"{
+  "smart_status": {"passed": false},
+  "temperature": {"current": 52},
+  "ata_smart_attributes": {
+    "table": [
+      {"id": 5, "name": "Reallocated_Sector_Ct", "raw": {"value": 47}, "value": 150}
+    ]
+  }
+}"#;
+
+#[test]
+fn test_parse_smart_json_fail() {
+    let result = smart::parse_json(SMART_JSON_FAIL).unwrap();
+    assert!(!result.passed);
+    assert_eq!(result.reallocated_sectors, Some(47));
+}
+
+#[test]
+fn test_smart_disponible() {
+    let _ = smart::is_available();
+}