Adding translation layer for pre-API libcontainer configs.
This commit is contained in:
Victor Marmol
parent
a7d52293c8
commit
e97e203d76
275
container/libcontainer/compatability.go
Normal file
275
container/libcontainer/compatability.go
Normal file
@ -0,0 +1,275 @@
|
||||
// Copyright 2015 Google Inc. All Rights Reserved.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
package libcontainer
|
||||
|
||||
import (
|
||||
"encoding/json"
|
||||
"io/ioutil"
|
||||
"path"
|
||||
|
||||
"github.com/docker/libcontainer"
|
||||
"github.com/docker/libcontainer/configs"
|
||||
"github.com/google/cadvisor/utils"
|
||||
)
|
||||
|
||||
// State represents a running container's state
|
||||
type preAPIState struct {
|
||||
// InitPid is the init process id in the parent namespace
|
||||
InitPid int `json:"init_pid,omitempty"`
|
||||
|
||||
// InitStartTime is the init process start time
|
||||
InitStartTime string `json:"init_start_time,omitempty"`
|
||||
|
||||
// Network runtime state.
|
||||
NetworkState preAPINetworkState `json:"network_state,omitempty"`
|
||||
|
||||
// Path to all the cgroups setup for a container. Key is cgroup subsystem name.
|
||||
CgroupPaths map[string]string `json:"cgroup_paths,omitempty"`
|
||||
}
|
||||
|
||||
// Struct describing the network specific runtime state that will be maintained by libcontainer for all running containers
|
||||
// Do not depend on it outside of libcontainer.
|
||||
type preAPINetworkState struct {
|
||||
// The name of the veth interface on the Host.
|
||||
VethHost string `json:"veth_host,omitempty"`
|
||||
// The name of the veth interface created inside the container for the child.
|
||||
VethChild string `json:"veth_child,omitempty"`
|
||||
// Net namespace path.
|
||||
NsPath string `json:"ns_path,omitempty"`
|
||||
}
|
||||
|
||||
type preAPIConfig struct {
|
||||
// Pathname to container's root filesystem
|
||||
RootFs string `json:"root_fs,omitempty"`
|
||||
|
||||
// Hostname optionally sets the container's hostname if provided
|
||||
Hostname string `json:"hostname,omitempty"`
|
||||
|
||||
// User will set the uid and gid of the executing process running inside the container
|
||||
User string `json:"user,omitempty"`
|
||||
|
||||
// WorkingDir will change the processes current working directory inside the container's rootfs
|
||||
WorkingDir string `json:"working_dir,omitempty"`
|
||||
|
||||
// Env will populate the processes environment with the provided values
|
||||
// Any values from the parent processes will be cleared before the values
|
||||
// provided in Env are provided to the process
|
||||
Env []string `json:"environment,omitempty"`
|
||||
|
||||
// Tty when true will allocate a pty slave on the host for access by the container's process
|
||||
// and ensure that it is mounted inside the container's rootfs
|
||||
Tty bool `json:"tty,omitempty"`
|
||||
|
||||
// Namespaces specifies the container's namespaces that it should setup when cloning the init process
|
||||
// If a namespace is not provided that namespace is shared from the container's parent process
|
||||
Namespaces []configs.Namespace `json:"namespaces,omitempty"`
|
||||
|
||||
// Capabilities specify the capabilities to keep when executing the process inside the container
|
||||
// All capbilities not specified will be dropped from the processes capability mask
|
||||
Capabilities []string `json:"capabilities,omitempty"`
|
||||
|
||||
// Networks specifies the container's network setup to be created
|
||||
Networks []preAPINetwork `json:"networks,omitempty"`
|
||||
|
||||
// Routes can be specified to create entries in the route table as the container is started
|
||||
Routes []*configs.Route `json:"routes,omitempty"`
|
||||
|
||||
// Cgroups specifies specific cgroup settings for the various subsystems that the container is
|
||||
// placed into to limit the resources the container has available
|
||||
Cgroups *configs.Cgroup `json:"cgroups,omitempty"`
|
||||
|
||||
// AppArmorProfile specifies the profile to apply to the process running in the container and is
|
||||
// change at the time the process is execed
|
||||
AppArmorProfile string `json:"apparmor_profile,omitempty"`
|
||||
|
||||
// ProcessLabel specifies the label to apply to the process running in the container. It is
|
||||
// commonly used by selinux
|
||||
ProcessLabel string `json:"process_label,omitempty"`
|
||||
|
||||
// RestrictSys will remount /proc/sys, /sys, and mask over sysrq-trigger as well as /proc/irq and
|
||||
// /proc/bus
|
||||
RestrictSys bool `json:"restrict_sys,omitempty"`
|
||||
}
|
||||
|
||||
// Network defines configuration for a container's networking stack
|
||||
//
|
||||
// The network configuration can be omited from a container causing the
|
||||
// container to be setup with the host's networking stack
|
||||
type preAPINetwork struct {
|
||||
// Type sets the networks type, commonly veth and loopback
|
||||
Type string `json:"type,omitempty"`
|
||||
|
||||
// The bridge to use.
|
||||
Bridge string `json:"bridge,omitempty"`
|
||||
|
||||
// Prefix for the veth interfaces.
|
||||
VethPrefix string `json:"veth_prefix,omitempty"`
|
||||
|
||||
// MacAddress contains the MAC address to set on the network interface
|
||||
MacAddress string `json:"mac_address,omitempty"`
|
||||
|
||||
// Address contains the IPv4 and mask to set on the network interface
|
||||
Address string `json:"address,omitempty"`
|
||||
|
||||
// IPv6Address contains the IPv6 and mask to set on the network interface
|
||||
IPv6Address string `json:"ipv6_address,omitempty"`
|
||||
|
||||
// Gateway sets the gateway address that is used as the default for the interface
|
||||
Gateway string `json:"gateway,omitempty"`
|
||||
|
||||
// IPv6Gateway sets the ipv6 gateway address that is used as the default for the interface
|
||||
IPv6Gateway string `json:"ipv6_gateway,omitempty"`
|
||||
|
||||
// Mtu sets the mtu value for the interface and will be mirrored on both the host and
|
||||
// container's interfaces if a pair is created, specifically in the case of type veth
|
||||
// Note: This does not apply to loopback interfaces.
|
||||
Mtu int `json:"mtu,omitempty"`
|
||||
|
||||
// TxQueueLen sets the tx_queuelen value for the interface and will be mirrored on both the host and
|
||||
// container's interfaces if a pair is created, specifically in the case of type veth
|
||||
// Note: This does not apply to loopback interfaces.
|
||||
TxQueueLen int `json:"txqueuelen,omitempty"`
|
||||
}
|
||||
|
||||
// Relative path to the libcontainer execdriver directory.
|
||||
const libcontainerExecDriverPath = "execdriver/native"
|
||||
|
||||
// TODO(vmarmol): Deprecate over time as old Dockers are phased out.
|
||||
func ReadConfig(dockerRoot, dockerRun, containerID string) (*configs.Config, error) {
|
||||
// Try using the new config if it is available.
|
||||
configPath := configPath(dockerRun, containerID)
|
||||
if utils.FileExists(configPath) {
|
||||
out, err := ioutil.ReadFile(configPath)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
var state libcontainer.State
|
||||
err = json.Unmarshal(out, &state)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return &state.Config, nil
|
||||
}
|
||||
|
||||
// Fallback to reading the old config which is comprised of the state and config files.
|
||||
oldConfigPath := oldConfigPath(dockerRoot, containerID)
|
||||
out, err := ioutil.ReadFile(oldConfigPath)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// Try reading the preAPIConfig.
|
||||
var config preAPIConfig
|
||||
err = json.Unmarshal(out, &config)
|
||||
if err != nil {
|
||||
// Try to parse the old pre-API config. The main difference is that namespaces used to be a map, now it is a slice of structs.
|
||||
// The JSON marshaler will use the non-nested field before the nested one.
|
||||
type oldLibcontainerConfig struct {
|
||||
preAPIConfig
|
||||
OldNamespaces map[string]bool `json:"namespaces,omitempty"`
|
||||
}
|
||||
var oldConfig oldLibcontainerConfig
|
||||
err2 := json.Unmarshal(out, &oldConfig)
|
||||
if err2 != nil {
|
||||
// Use original error.
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// Translate the old pre-API config into the new config.
|
||||
config = oldConfig.preAPIConfig
|
||||
for ns := range oldConfig.OldNamespaces {
|
||||
config.Namespaces = append(config.Namespaces, configs.Namespace{
|
||||
Type: configs.NamespaceType(ns),
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
// Read the old state file as well.
|
||||
state, err := readState(dockerRoot, containerID)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// Convert preAPIConfig + old state file to Config.
|
||||
// This only converts some of the fields, the ones we use.
|
||||
// You may need to add fields if the one you're interested in is not available.
|
||||
var result configs.Config
|
||||
result.Cgroups = new(configs.Cgroup)
|
||||
result.Rootfs = config.RootFs
|
||||
result.Hostname = config.Hostname
|
||||
result.Namespaces = config.Namespaces
|
||||
result.Capabilities = config.Capabilities
|
||||
for _, net := range config.Networks {
|
||||
n := &configs.Network{
|
||||
Name: state.NetworkState.VethChild,
|
||||
Bridge: net.Bridge,
|
||||
MacAddress: net.MacAddress,
|
||||
Address: net.Address,
|
||||
Gateway: net.Gateway,
|
||||
IPv6Address: net.IPv6Address,
|
||||
IPv6Gateway: net.IPv6Gateway,
|
||||
HostInterfaceName: state.NetworkState.VethHost,
|
||||
}
|
||||
result.Networks = append(result.Networks, n)
|
||||
}
|
||||
result.Routes = config.Routes
|
||||
if config.Cgroups != nil {
|
||||
result.Cgroups = config.Cgroups
|
||||
}
|
||||
|
||||
return &result, nil
|
||||
}
|
||||
|
||||
func readState(dockerRoot, containerID string) (preAPIState, error) {
|
||||
// pre-API libcontainer changed how its state was stored, try the old way of a "pid" file
|
||||
statePath := path.Join(dockerRoot, libcontainerExecDriverPath, containerID, "state.json")
|
||||
if !utils.FileExists(statePath) {
|
||||
pidPath := path.Join(dockerRoot, libcontainerExecDriverPath, containerID, "pid")
|
||||
if utils.FileExists(pidPath) {
|
||||
// We don't need the old state, return an empty state and we'll gracefully degrade.
|
||||
return preAPIState{}, nil
|
||||
}
|
||||
}
|
||||
out, err := ioutil.ReadFile(statePath)
|
||||
if err != nil {
|
||||
return preAPIState{}, err
|
||||
}
|
||||
|
||||
// Parse the state.
|
||||
var state preAPIState
|
||||
err = json.Unmarshal(out, &state)
|
||||
if err != nil {
|
||||
return preAPIState{}, err
|
||||
}
|
||||
|
||||
return state, nil
|
||||
}
|
||||
|
||||
// Gets the path to the libcontainer configuration.
|
||||
func configPath(dockerRun, containerID string) string {
|
||||
return path.Join(dockerRun, libcontainerExecDriverPath, containerID, "state.json")
|
||||
}
|
||||
|
||||
// Gets the path to the old libcontainer configuration.
|
||||
func oldConfigPath(dockerRoot, containerID string) string {
|
||||
return path.Join(dockerRoot, libcontainerExecDriverPath, containerID, "container.json")
|
||||
}
|
||||
|
||||
// Gets whether the specified container exists.
|
||||
func Exists(dockerRoot, dockerRun, containerID string) bool {
|
||||
// New or old config must exist for the container to be considered alive.
|
||||
return utils.FileExists(configPath(dockerRun, containerID)) || utils.FileExists(oldConfigPath(dockerRoot, containerID))
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user