Use host network not working as expected when host interface has multiple IP addresses

[whoteit92]

When the host network interface has multiple IP addresses, using the host network (by omitting the network namespace from config.json) does not work as expected. The container interface only has 1 IP address assigned.

On host: ip address show eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq state UP group default qlen 1000 link/ether ac:cc:8e:b3:63:29 brd ff:ff:ff:ff:ff:ff permaddr 00:40:8c:cd:00:00 inet 169.254.158.140/16 scope link eth0 valid_lft forever preferred_lft forever inet 192.168.1.122/24 brd 192.168.1.255 scope global eth0 valid_lft forever preferred_lft forever

On container root@12345:~# runc exec mycontainer ifconfig eth0 Link encap:Ethernet HWaddr AC:CC:8E:B3:63:29 inet addr:169.254.158.140 Bcast:0.0.0.0 Mask:255.255.0.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:619 errors:0 dropped:115 overruns:0 frame:0 TX packets:931 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:51549 (50.3 KiB) TX bytes:176770 (172.6 KiB)

Full config.json

{
	"ociVersion": "1.0.2-dev",
	"process": {
		"terminal": false,
		"user": {
			"uid": 0,
			"gid": 0
		},
		"args": [
			"./Test"
		],
		"env": [
			"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
			"TERM=xterm"
		],
		"cwd": "/app/Test/",
		"capabilities": {
			"bounding": [
				"CAP_AUDIT_WRITE",
				"CAP_KILL",
				"CAP_NET_BIND_SERVICE"
			],
			"effective": [
				"CAP_AUDIT_WRITE",
				"CAP_KILL",
				"CAP_NET_BIND_SERVICE"
			],
			"inheritable": [
				"CAP_AUDIT_WRITE",
				"CAP_KILL",
				"CAP_NET_BIND_SERVICE"
			],
			"permitted": [
				"CAP_AUDIT_WRITE",
				"CAP_KILL",
				"CAP_NET_BIND_SERVICE"
			],
			"ambient": [
				"CAP_AUDIT_WRITE",
				"CAP_KILL",
				"CAP_NET_BIND_SERVICE"
			]
		},
		"rlimits": [
			{
				"type": "RLIMIT_NOFILE",
				"hard": 1024,
				"soft": 1024
			}
		],
		"noNewPrivileges": true
	},
	"root": {
		"path": "rootfs",
		"readonly": false
	},
	"hostname": "TEST",
	"mounts": [
		{
			"destination": "/proc",
			"type": "proc",
			"source": "proc"
		},
		{
			"destination": "/dev",
			"type": "tmpfs",
			"source": "tmpfs",
			"options": [
				"nosuid",
				"strictatime",
				"mode=755",
				"size=65536k"
			]
		},
		{
			"destination": "/dev/pts",
			"type": "devpts",
			"source": "devpts",
			"options": [
				"nosuid",
				"noexec",
				"newinstance",
				"ptmxmode=0666",
				"mode=0620",
				"gid=5"
			]
		},
		{
			"destination": "/dev/shm",
			"type": "tmpfs",
			"source": "shm",
			"options": [
				"nosuid",
				"noexec",
				"nodev",
				"mode=1777",
				"size=65536k"
			]
		},
		{
			"destination": "/dev/mqueue",
			"type": "mqueue",
			"source": "mqueue",
			"options": [
				"nosuid",
				"noexec",
				"nodev"
			]
		},
		{
			"destination": "/sys",
			"type": "sysfs",
			"source": "sysfs",
			"options": [
				"nosuid",
				"noexec",
				"nodev",
				"ro"
			]
		},
		{
			"destination": "/sys/fs/cgroup",
			"type": "cgroup",
			"source": "cgroup",
			"options": [
				"nosuid",
				"noexec",
				"nodev",
				"relatime",
				"ro"
			]
		}
	],

	"linux": {
		"resources": {
			"devices": [
				{
					"allow": false,
					"access": "rwm"
				}
			]
		},
		"namespaces": [
			{
				"type": "pid"
			},
			{
				"type": "ipc"
			},
			{
				"type": "uts"
			},
			{
				"type": "mount"
			}
		],
		"maskedPaths": [
			"/proc/acpi",
			"/proc/asound",
			"/proc/kcore",
			"/proc/keys",
			"/proc/latency_stats",
			"/proc/timer_list",
			"/proc/timer_stats",
			"/proc/sched_debug",
			"/sys/firmware",
			"/proc/scsi"
		],
		"readonlyPaths": [
			"/proc/bus",
			"/proc/fs",
			"/proc/irq",
			"/proc/sys",
			"/proc/sysrq-trigger"
		]
	}
}

[chenk008]

Please use ip address show in your container, it seems different between ip and ifconfig.

[whoteit92]

That is not the issue. ip address show in the container also shows a missing IP address :

root@axis-accc8eb36329:~# runc exec mycontainer ip address show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq state UP qlen 1000 link/ether ac:cc:8e:b3:63:29 brd ff:ff:ff:ff:ff:ff inet 169.254.12.138/16 scope link eth0 valid_lft forever preferred_lft forever inet 192.168.1.122/24 brd 192.168.1.255 scope global eth0 valid_lft forever preferred_lft forever

[kamizjw]

try add --net host when executing runc run command，expect your execution result