fix: fix containerd mergeddir (#92)

pkg/cri/containerdutils/containerd_k3s.go

@@ -0,0 +1,11 @@
+/*
+ * Copyright 2022 Holoinsight Project Authors. Licensed under Apache-2.0.
+ */
+
+package containerdutils
+
+// K3s is a commonly used distribution of K8s and we have built-in support for it.
+const (
+	K3sDefaultStateDir = "/run/k3s/containerd"
+	K3sDefaultAddress  = "/run/k3s/containerd/containerd.sock"
+)

pkg/cri/containerdutils/utils.go

@@ -8,14 +8,15 @@ import (
 	"context"
 	"errors"
 	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/defaults"
 	"github.com/traas-stack/holoinsight-agent/pkg/core"
 	"time"
 )
 
 // NewClientFromEnv create a containerd client based on the agreed environment configuration information.
 func NewClientFromEnv(addrs ...string) (*containerd.Client, containerd.Version, error) {
 	// Default to two well known containerd sock
-	defaultAddrs := append(addrs, "/run/containerd/containerd.sock", "/run/k3s/containerd/containerd.sock")
+	defaultAddrs := append(addrs, defaults.DefaultAddress, K3sDefaultAddress)
 
 	addr := core.FindFirstSockInHostfs("CONTAINERD_SOCK", defaultAddrs...)
 	if addr == "" {

pkg/cri/impl/engine/containerd_engine.go

@@ -14,7 +14,10 @@ import (
 	"github.com/containerd/containerd"
 	"github.com/containerd/containerd/api/services/tasks/v1"
 	"github.com/containerd/containerd/cio"
+	"github.com/containerd/containerd/defaults"
 	runc_options "github.com/containerd/containerd/runtime/v2/runc/options"
+	"github.com/traas-stack/holoinsight-agent/pkg/core"
+	"github.com/traas-stack/holoinsight-agent/pkg/cri/containerdutils"
 	"github.com/traas-stack/holoinsight-agent/pkg/logger"
 	"github.com/traas-stack/holoinsight-agent/pkg/util"
 	"go.uber.org/zap"
@@ -215,10 +218,24 @@ func (e *ContainerdContainerEngine) GetContainerDetail(ctx context.Context, cid
 		detail.NetworkMode = "netns:" + sandboxMeta.NetNSPath
 	}
 
+	// I don't know how to get containerd's state dir.
+	// But I know its default value.
+	// Tested OK on containerd v1.6.8.
+	maybeContainerdStateDirs := []string{defaults.DefaultStateDir, containerdutils.K3sDefaultStateDir}
+	for _, stateDir := range maybeContainerdStateDirs {
+		// TODO It seems that for the old version of containerd, the rootfs of the container is not this.
+		containerRootfs := filepath.Join(stateDir, "io.containerd.runtime.v2.task", "k8s.io", cid, "rootfs")
+		if st, err := os.Stat(filepath.Join(core.GetHostfs(), containerRootfs)); err == nil && st.IsDir() {
+			detail.MergedDir = containerRootfs
+			break
+		}
+	}
+
 	logger.Debugz("[containerd] details",
 		zap.String("cid", cid),
 		zap.Any("container", &container),
-		zap.Any("runtime", runtime),
+		zap.Any("runtime", &runtime),
+		zap.Any("spec", &spec),
 		zap.Any("containerMeta", &containerMeta),
 		zap.Any("sandboxMeta", &sandboxMeta),
 	)