Merge pull request #23083 from Luap99/restore-hosts

restore: fix missing network setup

libpod/container_internal_common.go

@@ -1725,6 +1725,15 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti
 		}
 	}
 
+	// setup hosts/resolv.conf files
+	// Note this should normally be called after the container is created in the runtime but before it is started.
+	// However restore starts the container right away. This means that if we do the call afterwards there is a
+	// short interval where the file is still empty. Thus I decided to call it before which makes it not working
+	// with PostConfigureNetNS (userns) but as this does not work anyway today so I don't see it as problem.
+	if err := c.completeNetworkSetup(); err != nil {
+		return nil, 0, fmt.Errorf("complete network setup: %w", err)
+	}
+
 	runtimeRestoreDuration, err = c.ociRuntime.CreateContainer(c, &options)
 	if err != nil {
 		return nil, 0, err

test/system/520-checkpoint.bats

@@ -247,6 +247,9 @@ function teardown() {
     run_podman inspect $cid --format "{{(index .NetworkSettings.Networks \"$netname\").MacAddress}}"
     mac1="$output"
 
+    run_podman exec $cid cat /etc/hosts /etc/resolv.conf
+    pre_hosts_resolv_conf_output="$output"
+
     run_podman container checkpoint $cid
     is "$output" "$cid"
     run_podman container restore $cid
@@ -258,6 +261,10 @@ function teardown() {
     run_podman inspect $cid --format "{{(index .NetworkSettings.Networks \"$netname\").MacAddress}}"
     mac2="$output"
 
+    # Make sure hosts and resolv.conf are the same after restore (#22901)
+    run_podman exec $cid cat /etc/hosts /etc/resolv.conf
+    assert "$output" == "$pre_hosts_resolv_conf_output" "hosts/resolv.conf must be the same after checkpoint"
+
     assert "$ip2" == "$ip1" "ip after restore should match"
     assert "$mac2" == "$mac1" "mac after restore should match"