in_podman_metrics: Fixed reading undefined PID

In case of not found pid file, it took a form of
UINT64_MAX, after that plugin tried to read from it
from proc. Fixed it. Also added alternative path for
cgroupsv2 pid file.

Signed-off-by: Paweł Cendrzak <[email protected]>

Author: pabloxxl

plugins/in_podman_metrics/podman_metrics_config.h

@@ -106,6 +106,7 @@
 #define V2_SYSFS_FILE_MEMORY_LIMIT     "memory.max"
 #define V2_SYSFS_FILE_CPU_STAT         "cpu.stat"
 #define V2_SYSFS_FILE_PIDS             "cgroup.procs"
+#define V2_SYSFS_FILE_PIDS_ALT         "containers/cgroup.procs"
 
 /* Values used to construct counters/gauges names and descriptions */
 #define COUNTER_PREFIX                  "container"

plugins/in_podman_metrics/podman_metrics_data.c

@@ -331,9 +331,12 @@ int fill_counters_with_sysfs_data_v1(struct flb_in_metrics *ctx)
         cnt->cpu_user = get_data_from_sysfs(ctx, cpu_path, V1_SYSFS_FILE_CPU_USER, NULL);
         cnt->cpu = get_data_from_sysfs(ctx, cpu_path, V1_SYSFS_FILE_CPU, NULL);
         pid = get_data_from_sysfs(ctx, systemd_path, V1_SYSFS_FILE_PIDS, NULL);
-        if (pid) {
+        if (pid && pid != UINT64_MAX) {
             get_net_data_from_proc(ctx, cnt, pid);
         }
+        else {
+            flb_plg_warn(ctx->ins, "Failed to collect PID for %s", cnt->name);
+        }
     }
     return 0;
 }
@@ -364,9 +367,15 @@ int fill_counters_with_sysfs_data_v2(struct flb_in_metrics *ctx)
         cnt->cpu_user = get_data_from_sysfs(ctx, path, V2_SYSFS_FILE_CPU_STAT, STAT_KEY_CPU_USER);
         cnt->cpu = get_data_from_sysfs(ctx, path, V2_SYSFS_FILE_CPU_STAT, STAT_KEY_CPU);
         pid = get_data_from_sysfs(ctx, path, V2_SYSFS_FILE_PIDS, NULL);
-        if (pid) {
+        if (!pid || pid == UINT64_MAX) {
+            pid = get_data_from_sysfs(ctx, path, V2_SYSFS_FILE_PIDS_ALT, NULL);
+        }
+        if (pid && pid != UINT64_MAX) {
             get_net_data_from_proc(ctx, cnt, pid);
         }
+        else {
+            flb_plg_warn(ctx->ins, "Failed to collect PID for %s", cnt->name);
+        }
     }
     return 0;
 }

tests/runtime/data/podman/cgroupv2/18446744073709551615/net/dev renamed to tests/runtime/data/podman/cgroupv2/42/net/dev

@@ -0,0 +1 @@
+42

tests/runtime/data/podman/cgroupv2/memory/libpod-8a19d6058bfbe88cd0548eba9047d94c70161f5d74b545c7504b2f27491686d9/memory.current renamed to tests/runtime/data/podman/cgroupv2/libpod-8a19d6058bfbe88cd0548eba9047d94c70161f5d74b545c7504b2f27491686d9/containers/cgroup.procs

@@ -0,0 +1,3 @@
+42
+73
+12