agent: Avoid container stats panic caused by cgroup controller non-exist

Return SingularPtrField::none() instead of panic when getting stats
from cgroup failed caused by cgroup controller missing.

Signed-off-by: Tim Zhang <tim@hyper.sh>

src/agent/rustjail/src/cgroups/fs/mod.rs

@@ -44,6 +44,15 @@ macro_rules! sl {
     };
 }
 
+macro_rules! get_controller_or_return_singular_none {
+    ($cg:ident) => {
+        match $cg.controller_of() {
+            Some(c) => c,
+            None => return SingularPtrField::none(),
+        }
+    };
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Manager {
     pub paths: HashMap<String, String>,
@@ -561,10 +570,8 @@ lazy_static! {
 }
 
 fn get_cpu_stats(cg: &cgroups::Cgroup) -> SingularPtrField<ThrottlingData> {
-    let cpu_controller: &CpuController = cg.controller_of().unwrap();
+    let cpu_controller: &CpuController = get_controller_or_return_singular_none!(cg);
-
     let stat = cpu_controller.cpu().stat;
-
     let h = lines_to_map(&stat);
 
     SingularPtrField::some(ThrottlingData {
@@ -577,39 +584,7 @@ fn get_cpu_stats(cg: &cgroups::Cgroup) -> SingularPtrField<ThrottlingData> {
 }
 
 fn get_cpuacct_stats(cg: &cgroups::Cgroup) -> SingularPtrField<CpuUsage> {
-    let cpuacct_controller: Option<&CpuAcctController> = cg.controller_of();
+    if let Some(cpuacct_controller) = cg.controller_of::<CpuAcctController>() {
-    if cpuacct_controller.is_none() {
-        if cg.v2() {
-            return SingularPtrField::some(CpuUsage {
-                total_usage: 0,
-                percpu_usage: vec![],
-                usage_in_kernelmode: 0,
-                usage_in_usermode: 0,
-                unknown_fields: UnknownFields::default(),
-                cached_size: CachedSize::default(),
-            });
-        }
-
-        // try to get from cpu controller
-        let cpu_controller: &CpuController = cg.controller_of().unwrap();
-        let stat = cpu_controller.cpu().stat;
-        let h = lines_to_map(&stat);
-        let usage_in_usermode = *h.get("user_usec").unwrap();
-        let usage_in_kernelmode = *h.get("system_usec").unwrap();
-        let total_usage = *h.get("usage_usec").unwrap();
-        let percpu_usage = vec![];
-
-        return SingularPtrField::some(CpuUsage {
-            total_usage,
-            percpu_usage,
-            usage_in_kernelmode,
-            usage_in_usermode,
-            unknown_fields: UnknownFields::default(),
-            cached_size: CachedSize::default(),
-        });
-    }
-
-    let cpuacct_controller = cpuacct_controller.unwrap();
         let cpuacct = cpuacct_controller.cpuacct();
 
         let h = lines_to_map(&cpuacct.stat);
@@ -622,6 +597,36 @@ fn get_cpuacct_stats(cg: &cgroups::Cgroup) -> SingularPtrField<CpuUsage> {
 
         let percpu_usage = line_to_vec(&cpuacct.usage_percpu);
 
+        return SingularPtrField::some(CpuUsage {
+            total_usage,
+            percpu_usage,
+            usage_in_kernelmode,
+            usage_in_usermode,
+            unknown_fields: UnknownFields::default(),
+            cached_size: CachedSize::default(),
+        });
+    }
+
+    if cg.v2() {
+        return SingularPtrField::some(CpuUsage {
+            total_usage: 0,
+            percpu_usage: vec![],
+            usage_in_kernelmode: 0,
+            usage_in_usermode: 0,
+            unknown_fields: UnknownFields::default(),
+            cached_size: CachedSize::default(),
+        });
+    }
+
+    // try to get from cpu controller
+    let cpu_controller: &CpuController = get_controller_or_return_singular_none!(cg);
+    let stat = cpu_controller.cpu().stat;
+    let h = lines_to_map(&stat);
+    let usage_in_usermode = *h.get("user_usec").unwrap();
+    let usage_in_kernelmode = *h.get("system_usec").unwrap();
+    let total_usage = *h.get("usage_usec").unwrap();
+    let percpu_usage = vec![];
+
     SingularPtrField::some(CpuUsage {
         total_usage,
         percpu_usage,
@@ -633,7 +638,7 @@ fn get_cpuacct_stats(cg: &cgroups::Cgroup) -> SingularPtrField<CpuUsage> {
 }
 
 fn get_memory_stats(cg: &cgroups::Cgroup) -> SingularPtrField<MemoryStats> {
-    let memory_controller: &MemController = cg.controller_of().unwrap();
+    let memory_controller: &MemController = get_controller_or_return_singular_none!(cg);
 
     // cache from memory stat
     let memory = memory_controller.memory_stat();
@@ -690,7 +695,7 @@ fn get_memory_stats(cg: &cgroups::Cgroup) -> SingularPtrField<MemoryStats> {
 }
 
 fn get_pids_stats(cg: &cgroups::Cgroup) -> SingularPtrField<PidsStats> {
-    let pid_controller: &PidController = cg.controller_of().unwrap();
+    let pid_controller: &PidController = get_controller_or_return_singular_none!(cg);
 
     let current = pid_controller.get_pid_current().unwrap_or(0);
     let max = pid_controller.get_pid_max();
@@ -796,7 +801,7 @@ fn build_blkio_stats_entry(major: i16, minor: i16, op: &str, value: u64) -> Blki
 }
 
 fn get_blkio_stats_v2(cg: &cgroups::Cgroup) -> SingularPtrField<BlkioStats> {
-    let blkio_controller: &BlkIoController = cg.controller_of().unwrap();
+    let blkio_controller: &BlkIoController = get_controller_or_return_singular_none!(cg);
     let blkio = blkio_controller.blkio();
 
     let mut resp = BlkioStats::new();
@@ -824,7 +829,7 @@ fn get_blkio_stats(cg: &cgroups::Cgroup) -> SingularPtrField<BlkioStats> {
         return get_blkio_stats_v2(&cg);
     }
 
-    let blkio_controller: &BlkIoController = cg.controller_of().unwrap();
+    let blkio_controller: &BlkIoController = get_controller_or_return_singular_none!(cg);
     let blkio = blkio_controller.blkio();
 
     let mut m = BlkioStats::new();