shimv2: log a warning and continue on post-start hook failure

According to runtime-spec:
The poststart hooks MUST be invoked by the runtime. If any poststart
hook fails, the runtime MUST log a warning, but the remaining hooks
and lifecycle continue as if the hook had succeeded

backport from 2.0, kata-containers/kata-containers#1253

Fixes: #3126

Signed-off-by: Snir Sheriber <[email protected]>

Author: snir911

containerd-shim-v2/start.go

@@ -11,6 +11,8 @@ import (
 
 	"github.com/containerd/containerd/api/types/task"
 	"github.com/kata-containers/runtime/pkg/katautils"
+
+	"github.com/sirupsen/logrus"
 )
 
 func startContainer(ctx context.Context, s *service, c *container) error {
@@ -52,7 +54,9 @@ func startContainer(ctx context.Context, s *service, c *container) error {
 		return katautils.PostStartHooks(ctx, *c.spec, s.sandbox.ID(), c.bundle)
 	})
 	if err != nil {
-		return err
+		// log warning and continue, as defined in oci runtime spec
+		// https://github.com/opencontainers/runtime-spec/blob/master/runtime.md#lifecycle
+		logrus.WithError(err).Warn("Failed to run post-start hooks")
 	}
 
 	c.status = task.StatusRunning