From 21651706e3277cbf4d646f7f5eddcf2d9e0e25b6 Mon Sep 17 00:00:00 2001
From: Daniel J Walsh <dwalsh@redhat.com>
Date: Mon, 6 Feb 2023 16:10:20 -0500
Subject: [PATCH] podman inspect list network when using --net=host or none

This will match Docker behaviour.

Fixes: https://github.com/containers/podman/issues/17385

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
---
 libpod/networking_common.go     | 22 +++++++++++++++++-----
 test/apiv2/20-containers.at     |  2 +-
 test/system/500-networking.bats | 31 +++++++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/libpod/networking_common.go b/libpod/networking_common.go
index 816e1d1c08..a569e9eaed 100644
--- a/libpod/networking_common.go
+++ b/libpod/networking_common.go
@@ -240,18 +240,26 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e
 		return nil, err
 	}
 
+	setDefaultNetworks := func() {
+		settings.Networks = make(map[string]*define.InspectAdditionalNetwork, 1)
+		name := c.NetworkMode()
+		addedNet := new(define.InspectAdditionalNetwork)
+		addedNet.NetworkID = name
+		settings.Networks[name] = addedNet
+	}
+
 	if c.state.NetNS == "" {
 		if networkNSPath := c.joinedNetworkNSPath(); networkNSPath != "" {
 			if result, err := c.inspectJoinedNetworkNS(networkNSPath); err == nil {
 				// fallback to dummy configuration
 				settings.InspectBasicNetworkConfig = resultToBasicNetworkConfig(result)
-				return settings, nil
+			} else {
+				// do not propagate error inspecting a joined network ns
+				logrus.Errorf("Inspecting network namespace: %s of container %s: %v", networkNSPath, c.ID(), err)
 			}
-			// do not propagate error inspecting a joined network ns
-			logrus.Errorf("Inspecting network namespace: %s of container %s: %v", networkNSPath, c.ID(), err)
+			return settings, nil
 		}
 		// We can't do more if the network is down.
-
 		// We still want to make dummy configurations for each network
 		// the container joined.
 		if len(networks) > 0 {
@@ -262,6 +270,8 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e
 				cniNet.Aliases = opts.Aliases
 				settings.Networks[net] = cniNet
 			}
+		} else {
+			setDefaultNetworks()
 		}
 
 		return settings, nil
@@ -282,7 +292,7 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e
 			return nil, fmt.Errorf("network inspection mismatch: asked to join %d network(s) %v, but have information on %d network(s): %w", len(networks), networks, len(netStatus), define.ErrInternal)
 		}
 
-		settings.Networks = make(map[string]*define.InspectAdditionalNetwork)
+		settings.Networks = make(map[string]*define.InspectAdditionalNetwork, len(networks))
 
 		for name, opts := range networks {
 			result := netStatus[name]
@@ -300,6 +310,8 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e
 		if !(len(networks) == 1 && isDefaultNet) {
 			return settings, nil
 		}
+	} else {
+		setDefaultNetworks()
 	}
 
 	// If not joining networks, we should have at most 1 result
diff --git a/test/apiv2/20-containers.at b/test/apiv2/20-containers.at
index 57adb02ae1..e77a8b09ac 100644
--- a/test/apiv2/20-containers.at
+++ b/test/apiv2/20-containers.at
@@ -51,7 +51,7 @@ t GET libpod/containers/json?all=true 200 \
   .[0].IsInfra=false
 
 # Test compat API for Network Settings (.Network is N/A when rootless)
-network_expect="Networks=null"
+network_expect="Networks.slirp4netns.NetworkID=slirp4netns"
 if root; then
     network_expect="Networks.podman.NetworkID=podman"
 fi
diff --git a/test/system/500-networking.bats b/test/system/500-networking.bats
index 01a30973c2..e20965fd25 100644
--- a/test/system/500-networking.bats
+++ b/test/system/500-networking.bats
@@ -806,4 +806,35 @@ EOF
     assert "$output" =~ "eth0"
 }
 
+@test "podman inspect list networks " {
+    run_podman create $IMAGE
+    cid=${output}
+    run_podman inspect --format '{{ .NetworkSettings.Networks }}' $cid
+    if is_rootless; then
+        is "$output" "map\[slirp4netns:.*" "NeworkSettings should contain one network named slirp4netns"
+    else
+        is "$output" "map\[podman:.*" "NeworkSettings should contain one network named podman"
+    fi
+    run_podman rm $cid
+
+    for network in "host" "none"; do
+        run_podman create --network=$network $IMAGE
+        cid=${output}
+        run_podman inspect --format '{{ .NetworkSettings.Networks }}' $cid
+        is "$output" "map\[$network:.*" "NeworkSettincs should contain one network named $network"
+        run_podman rm $cid
+    done
+
+    # Check with ns:/PATH
+    if ! is_rootless; then
+        netns=netns$(random_string)
+        ip netns add $netns
+        run_podman create --network=ns:/var/run/netns/$netns $IMAGE
+        cid=${output}
+        run_podman inspect --format '{{ .NetworkSettings.Networks }}' $cid
+        is "$output" 'map[]' "NeworkSettings should be empty"
+        run_podman rm $cid
+     fi
+}
+
 # vim: filetype=sh