k3s/vendor/k8s.io/legacy-cloud-providers/openstack/metadata.go
2019-12-15 23:28:25 -07:00

201 lines
5.9 KiB
Go

// +build !providerless
/*
Copyright 2016 The Kubernetes Authors.
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 openstack
import (
"encoding/json"
"errors"
"fmt"
"io"
"io/ioutil"
"net/http"
"os"
"path/filepath"
"strings"
"k8s.io/klog"
"k8s.io/utils/exec"
"k8s.io/utils/mount"
)
const (
// metadataURLTemplate allows building an OpenStack Metadata service URL.
// It's a hardcoded IPv4 link-local address as documented in "OpenStack Cloud
// Administrator Guide", chapter Compute - Networking with nova-network.
//https://docs.openstack.org/nova/latest/admin/networking-nova.html#metadata-service
defaultMetadataVersion = "2012-08-10"
metadataURLTemplate = "http://169.254.169.254/openstack/%s/meta_data.json"
// metadataID is used as an identifier on the metadata search order configuration.
metadataID = "metadataService"
// Config drive is defined as an iso9660 or vfat (deprecated) drive
// with the "config-2" label.
//https://docs.openstack.org/nova/latest/user/config-drive.html
configDriveLabel = "config-2"
configDrivePathTemplate = "openstack/%s/meta_data.json"
// configDriveID is used as an identifier on the metadata search order configuration.
configDriveID = "configDrive"
)
// ErrBadMetadata is used to indicate a problem parsing data from metadata server
var ErrBadMetadata = errors.New("invalid OpenStack metadata, got empty uuid")
// DeviceMetadata is a single/simplified data structure for all kinds of device metadata types.
type DeviceMetadata struct {
Type string `json:"type"`
Bus string `json:"bus,omitempty"`
Serial string `json:"serial,omitempty"`
Address string `json:"address,omitempty"`
// .. and other fields.
}
// Metadata has the information fetched from OpenStack metadata service or
// config drives. Assumes the "2012-08-10" meta_data.json format.
// See http://docs.openstack.org/user-guide/cli_config_drive.html
type Metadata struct {
UUID string `json:"uuid"`
Name string `json:"name"`
AvailabilityZone string `json:"availability_zone"`
Devices []DeviceMetadata `json:"devices,omitempty"`
// .. and other fields we don't care about. Expand as necessary.
}
// parseMetadata reads JSON from OpenStack metadata server and parses
// instance ID out of it.
func parseMetadata(r io.Reader) (*Metadata, error) {
var metadata Metadata
json := json.NewDecoder(r)
if err := json.Decode(&metadata); err != nil {
return nil, err
}
if metadata.UUID == "" {
return nil, ErrBadMetadata
}
return &metadata, nil
}
func getMetadataURL(metadataVersion string) string {
return fmt.Sprintf(metadataURLTemplate, metadataVersion)
}
func getConfigDrivePath(metadataVersion string) string {
return fmt.Sprintf(configDrivePathTemplate, metadataVersion)
}
func getMetadataFromConfigDrive(metadataVersion string) (*Metadata, error) {
// Try to read instance UUID from config drive.
dev := "/dev/disk/by-label/" + configDriveLabel
if _, err := os.Stat(dev); os.IsNotExist(err) {
out, err := exec.New().Command(
"blkid", "-l",
"-t", "LABEL="+configDriveLabel,
"-o", "device",
).CombinedOutput()
if err != nil {
return nil, fmt.Errorf("unable to run blkid: %v", err)
}
dev = strings.TrimSpace(string(out))
}
mntdir, err := ioutil.TempDir("", "configdrive")
if err != nil {
return nil, err
}
defer os.Remove(mntdir)
klog.V(4).Infof("Attempting to mount configdrive %s on %s", dev, mntdir)
mounter := mount.New("" /* default mount path */)
err = mounter.Mount(dev, mntdir, "iso9660", []string{"ro"})
if err != nil {
err = mounter.Mount(dev, mntdir, "vfat", []string{"ro"})
}
if err != nil {
return nil, fmt.Errorf("error mounting configdrive %s: %v", dev, err)
}
defer mounter.Unmount(mntdir)
klog.V(4).Infof("Configdrive mounted on %s", mntdir)
configDrivePath := getConfigDrivePath(metadataVersion)
f, err := os.Open(
filepath.Join(mntdir, configDrivePath))
if err != nil {
return nil, fmt.Errorf("error reading %s on config drive: %v", configDrivePath, err)
}
defer f.Close()
return parseMetadata(f)
}
func getMetadataFromMetadataService(metadataVersion string) (*Metadata, error) {
// Try to get JSON from metadata server.
metadataURL := getMetadataURL(metadataVersion)
klog.V(4).Infof("Attempting to fetch metadata from %s", metadataURL)
resp, err := http.Get(metadataURL)
if err != nil {
return nil, fmt.Errorf("error fetching %s: %v", metadataURL, err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
err = fmt.Errorf("unexpected status code when reading metadata from %s: %s", metadataURL, resp.Status)
return nil, err
}
return parseMetadata(resp.Body)
}
// Metadata is fixed for the current host, so cache the value process-wide
var metadataCache *Metadata
func getMetadata(order string) (*Metadata, error) {
if metadataCache == nil {
var md *Metadata
var err error
elements := strings.Split(order, ",")
for _, id := range elements {
id = strings.TrimSpace(id)
switch id {
case configDriveID:
md, err = getMetadataFromConfigDrive(defaultMetadataVersion)
case metadataID:
md, err = getMetadataFromMetadataService(defaultMetadataVersion)
default:
err = fmt.Errorf("%s is not a valid metadata search order option. Supported options are %s and %s", id, configDriveID, metadataID)
}
if err == nil {
break
}
}
if err != nil {
return nil, err
}
metadataCache = md
}
return metadataCache, nil
}