Function TestDockerContainerSpec

integration/tests/api/docker_test.go:180–240

TODO(vmarmol): Handle if CPU or memory is not isolated on this system. Check the ContainerSpec.

(t *testing.T)

// TODO(vmarmol): Handle if CPU or memory is not isolated on this system.
// Check the ContainerSpec.
func TestDockerContainerSpec(t *testing.T) {
	fm := framework.New(t)
	defer fm.Cleanup()

	var (
		cpuShares   = uint64(2048)
		cpuMask     = "0"
		memoryLimit = uint64(1 << 30) // 1GB
		image       = "registry.k8s.io/pause"
		env         = map[string]string{"test_var": "FOO"}
		labels      = map[string]string{"bar": "baz"}
	)

	containerID := fm.Docker().Run(framework.DockerRunArgs{
		Image: image,
		Args: []string{
			"--cpu-shares", strconv.FormatUint(cpuShares, 10),
			"--cpuset-cpus", cpuMask,
			"--memory", strconv.FormatUint(memoryLimit, 10),
			"--env", "TEST_VAR=FOO",
			"--label", "bar=baz",
		},
	})

	// Wait for the container to show up.
	waitForContainer(containerID, fm)

	request := &info.ContainerInfoRequest{
		NumStats: 1,
	}
	containerInfo, err := fm.Cadvisor().Client().DockerContainer(containerID, request)
	require.NoError(t, err)
	sanityCheck(containerID, containerInfo, t)

	assert := assert.New(t)

	assert.True(containerInfo.Spec.HasCpu, "CPU should be isolated")
	if cgroups.IsCgroup2UnifiedMode() {
		// cpu shares are converted on cgroupv2 due to conversion between cgroupv1 (cpu.shares) and cgroupv2 (cpu.weight)
		// When container is created via docker, runc will convert cpu shares to cpu.weight using a log2-based quadratic formula https://github.com/opencontainers/cgroups/blob/v0.0.6/utils.go#L405-L427
		// And cAdvisor will convert cpu.weight back to cpu shares in https://github.com/google/cadvisor/blob/24e7a9883d12f944fd4403861707f4bafcaf4f3d/container/common/helpers.go#L249-L260
		// Worked example:
		// cpuShares = 2048 (input to docker --cpu-shares)
		// l = log2(2048) = 11; exponent = (l*l + 125*l)/612 - 7/34 = 2.2386; cpuWeight = ceil(10^exponent) = 174 (conversion done by runc)
		// cpuWeight back to cpuShares = int(2 + ((cpuWeight-1)*262142)/9999)= 4537
		var cgroupV2Shares uint64 = 4537
		assert.Equal(cgroupV2Shares, containerInfo.Spec.Cpu.Limit, "Container should have %d shares, has %d", cgroupV2Shares, containerInfo.Spec.Cpu.Limit)
	} else {
		assert.Equal(cpuShares, containerInfo.Spec.Cpu.Limit, "Container should have %d shares, has %d", cpuShares, containerInfo.Spec.Cpu.Limit)
	}

	assert.Equal(cpuMask, containerInfo.Spec.Cpu.Mask, "Cpu mask should be %q, but is %q", cpuMask, containerInfo.Spec.Cpu.Mask)
	assert.True(containerInfo.Spec.HasMemory, "Memory should be isolated")
	assert.Equal(memoryLimit, containerInfo.Spec.Memory.Limit, "Container should have memory limit of %d, has %d", memoryLimit, containerInfo.Spec.Memory.Limit)
	assert.True(containerInfo.Spec.HasNetwork, "Network should be isolated")
	assert.True(containerInfo.Spec.HasDiskIo, "Blkio should be isolated")

	assert.Equal(image, containerInfo.Spec.Image, "Spec should include container image")