Fix memory and swap values reported by 'iotedge check' and edge agent (…

…#6943)

Fixes several bugs related to reported system RAM and swap values:
1. Units conversion bug introduced by a recent upgrade from sysinfo v0.25 to v0.27, resulting in edgeAgent_total_memory_bytes and edgeAgent_used_memory_bytes for "module_name=host" being 1024 times higher than the value previously reported in iotedge v1.4.3.
2. Long-standing bug in edgeAgent_total_memory_bytes and edgeAgent_used_memory_bytes for "module_name=host", where the reported values were 1.024 times higher than the actual values. This was caused by incorrectly treating the values returned by sysinfo v0.25 as KiB instead of KB.
3. Long-standing bug in system info reported by 'iotedge check', where the total_ram, total_swap, used_ram, and used_swap values were 1.024 times higher than the actual values. This was also caused by incorrectly treating the value returned by sysinfo v0.25 as KiB instead of KB.

The changes in this PR have been tested by building an aziot-edge package using the CI pipeline and installing it on a VM device. The 'iotedge check' and edgeAgent metrics were then checked to confirm that the values are now correct.

## Azure IoT Edge PR checklist:

edgelet/edgelet-docker/Cargo.toml

@@ -18,7 +18,7 @@ nix = "0.26"
 serde = "1"
 serde_json = "1"
 serial_test = "1"
-sysinfo = "0.27"
+sysinfo = "0.28"
 thiserror = "1"
 tokio = { version = "1", features = ["parking_lot", "sync"] }
 url = "2"

edgelet/edgelet-docker/src/runtime.rs

@@ -577,7 +577,7 @@ where
         let total_memory = {
             let mut system_resources = self.system_resources.as_ref().lock().await;
             system_resources.refresh_memory();
-            system_resources.total_memory() * 1024
+            total_memory_bytes(&system_resources)
         };
 
         let mut system_info = CoreSystemInfo::default();
@@ -616,8 +616,8 @@ where
             .as_secs();
 
         let used_cpu = system_resources.global_cpu_info().cpu_usage();
-        let total_memory = system_resources.total_memory() * 1024;
-        let used_memory = system_resources.used_memory() * 1024;
+        let total_memory = total_memory_bytes(&system_resources);
+        let used_memory = used_memory_bytes(&system_resources);
 
         let disks = system_resources
             .disks()
@@ -852,6 +852,14 @@ where
     }
 }
 
+fn total_memory_bytes(system_resources: &System) -> u64 {
+    system_resources.total_memory()
+}
+
+fn used_memory_bytes(system_resources: &System) -> u64 {
+    system_resources.used_memory()
+}
+
 fn parse_top_response<'de, D>(resp: &InlineResponse2001) -> Result<Vec<i32>, D::Error>
 where
     D: serde::Deserializer<'de>,
@@ -952,6 +960,8 @@ fn drop_unsafe_privileges(
 
 #[cfg(test)]
 mod tests {
+    use std::process::{Command, Stdio};
+
     use super::*;
 
     #[test]
@@ -1082,4 +1092,41 @@ mod tests {
             Some(&vec!["SETUID".to_owned()])
         );
     }
+
+    // Compare the total memory returned by the 'total_memory_bytes()' helper method
+    // to the value in /proc/meminfo
+    #[test]
+    fn test_total_memory_bytes() {
+        // Use 'total_memory_bytes()' helper method to get total memory
+        let system_resources = System::new_all();
+        let total_memory_bytes = total_memory_bytes(&system_resources);
+
+        // Get expected total memory directly from /proc/meminfo
+        let cat_proc_meminfo = Command::new("cat")
+            .arg("/proc/meminfo")
+            .stdout(Stdio::piped())
+            .spawn()
+            .expect("Failed to execute 'cat /proc/meminfo'");
+        let grep_memtotal = Command::new("grep")
+            .arg("-i")
+            .arg("memtotal")
+            .stdin(Stdio::from(cat_proc_meminfo.stdout.unwrap()))
+            .stdout(Stdio::piped())
+            .spawn()
+            .expect("Failed to execute 'grep -i memtotal'");
+        let grep_value = Command::new("grep")
+            .arg("-o")
+            .arg("[0-9]*")
+            .stdin(Stdio::from(grep_memtotal.stdout.unwrap()))
+            .stdout(Stdio::piped())
+            .spawn()
+            .expect("Failed to execute 'grep -o [0-9]*'");
+        let output = grep_value.wait_with_output().unwrap();
+        let expected_total_memory_kilobytes_str = str::from_utf8(&output.stdout).unwrap().trim();
+        let expected_total_memory_bytes =
+            expected_total_memory_kilobytes_str.parse::<u64>().unwrap() * 1024;
+
+        // Compare
+        assert_eq!(total_memory_bytes, expected_total_memory_bytes);
+    }
 }

edgelet/iotedge/Cargo.toml

@@ -28,7 +28,7 @@ nix = "0.26"
 regex = "1"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-sysinfo = "0.27"
+sysinfo = "0.28"
 tabwriter = "1"
 termcolor = "1"
 thiserror = "1"

edgelet/iotedge/src/check/additional_info.rs

@@ -190,7 +190,7 @@ impl DiskInfo {
 #[cfg(unix)]
 fn pretty_kbyte(bytes: u64) -> String {
     #[allow(clippy::cast_precision_loss)]
-    match Byte::from_unit(bytes as f64, ByteUnit::KiB) {
+    match Byte::from_unit(bytes as f64, ByteUnit::B) {
         Ok(b) => b.get_appropriate_unit(true).format(2),
         Err(err) => format!("could not parse bytes value: {:?}", err),
     }