From e3c9e064a930f5c8572c94ae8c782de01f206bbe Mon Sep 17 00:00:00 2001
From: Alex Suraci <suraci.alex@gmail.com>
Date: Thu, 18 Aug 2022 23:05:58 -0400
Subject: [PATCH] cniprovider: pass hostname as K8S_POD_NAME arg

Signed-off-by: Alex Suraci <suraci.alex@gmail.com>
---
 executor/containerdexecutor/executor.go |  2 +-
 executor/runcexecutor/executor.go       |  2 +-
 util/network/cniprovider/cni.go         | 20 +++++++++++++++-----
 util/network/host.go                    |  2 +-
 util/network/network.go                 |  2 +-
 util/network/none.go                    |  2 +-
 6 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/executor/containerdexecutor/executor.go b/executor/containerdexecutor/executor.go
index 9336a6489..4801a8488 100644
--- a/executor/containerdexecutor/executor.go
+++ b/executor/containerdexecutor/executor.go
@@ -146,7 +146,7 @@ func (w *containerdExecutor) Run(ctx context.Context, id string, root executor.M
 	if !ok {
 		return errors.Errorf("unknown network mode %s", meta.NetMode)
 	}
-	namespace, err := provider.New()
+	namespace, err := provider.New(meta.Hostname)
 	if err != nil {
 		return err
 	}
diff --git a/executor/runcexecutor/executor.go b/executor/runcexecutor/executor.go
index 702d51310..1755b5ed4 100644
--- a/executor/runcexecutor/executor.go
+++ b/executor/runcexecutor/executor.go
@@ -161,7 +161,7 @@ func (w *runcExecutor) Run(ctx context.Context, id string, root executor.Mount,
 	if !ok {
 		return errors.Errorf("unknown network mode %s", meta.NetMode)
 	}
-	namespace, err := provider.New()
+	namespace, err := provider.New(meta.Hostname)
 	if err != nil {
 		return err
 	}
diff --git a/util/network/cniprovider/cni.go b/util/network/cniprovider/cni.go
index edecd6c87..01ad0dad8 100644
--- a/util/network/cniprovider/cni.go
+++ b/util/network/cniprovider/cni.go
@@ -67,32 +67,42 @@ func (c *cniProvider) initNetwork() error {
 		}
 		defer l.Unlock()
 	}
-	ns, err := c.New()
+	ns, err := c.New("test")
 	if err != nil {
 		return err
 	}
 	return ns.Close()
 }
 
-func (c *cniProvider) New() (network.Namespace, error) {
+func (c *cniProvider) New(hostname string) (network.Namespace, error) {
 	id := identity.NewID()
 	nativeID, err := createNetNS(c, id)
 	if err != nil {
 		return nil, err
 	}
 
-	if _, err := c.CNI.Setup(context.TODO(), id, nativeID); err != nil {
+	nsOpts := []cni.NamespaceOpts{
+		// NB: K8S_POD_NAME is a semi-well-known arg set by k8s and podman and
+		// leveraged by the dnsname CNI plugin. a more generic name would be nice.
+		cni.WithArgs("K8S_POD_NAME", hostname),
+
+		// must be set for plugins that don't understand K8S_POD_NAME
+		cni.WithArgs("IgnoreUnknown", "1"),
+	}
+
+	if _, err := c.CNI.Setup(context.TODO(), id, nativeID, nsOpts...); err != nil {
 		deleteNetNS(nativeID)
 		return nil, errors.Wrap(err, "CNI setup error")
 	}
 
-	return &cniNS{nativeID: nativeID, id: id, handle: c.CNI}, nil
+	return &cniNS{nativeID: nativeID, id: id, handle: c.CNI, opts: nsOpts}, nil
 }
 
 type cniNS struct {
 	handle   cni.CNI
 	id       string
 	nativeID string
+	opts     []cni.NamespaceOpts
 }
 
 func (ns *cniNS) Set(s *specs.Spec) error {
@@ -100,7 +110,7 @@ func (ns *cniNS) Set(s *specs.Spec) error {
 }
 
 func (ns *cniNS) Close() error {
-	err := ns.handle.Remove(context.TODO(), ns.id, ns.nativeID)
+	err := ns.handle.Remove(context.TODO(), ns.id, ns.nativeID, ns.opts...)
 	if err1 := unmountNetNS(ns.nativeID); err1 != nil && err == nil {
 		err = err1
 	}
diff --git a/util/network/host.go b/util/network/host.go
index c50268d45..b390a54cd 100644
--- a/util/network/host.go
+++ b/util/network/host.go
@@ -15,7 +15,7 @@ func NewHostProvider() Provider {
 type host struct {
 }
 
-func (h *host) New() (Namespace, error) {
+func (h *host) New(hostname string) (Namespace, error) {
 	return &hostNS{}, nil
 }
 
diff --git a/util/network/network.go b/util/network/network.go
index befeef0c7..e0f5658eb 100644
--- a/util/network/network.go
+++ b/util/network/network.go
@@ -8,7 +8,7 @@ import (
 
 // Provider interface for Network
 type Provider interface {
-	New() (Namespace, error)
+	New(hostname string) (Namespace, error)
 }
 
 // Namespace of network for workers
diff --git a/util/network/none.go b/util/network/none.go
index 336ff68b9..81af7b17a 100644
--- a/util/network/none.go
+++ b/util/network/none.go
@@ -11,7 +11,7 @@ func NewNoneProvider() Provider {
 type none struct {
 }
 
-func (h *none) New() (Namespace, error) {
+func (h *none) New(hostname string) (Namespace, error) {
 	return &noneNS{}, nil
 }