cloudinit/initialize/meta_data.go

/*
   Copyright 2014 CoreOS, Inc.

   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 initialize

import (
	"encoding/json"
	"sort"

	"github.com/coreos/coreos-cloudinit/config"
)

// ParseMetaData parses a JSON blob in the OpenStack metadata service format,
// and converts it to a partially hydrated CloudConfig.
func ParseMetaData(contents string) (*config.CloudConfig, error) {
	if len(contents) == 0 {
		return nil, nil
	}
	var metadata struct {
		SSHAuthorizedKeyMap map[string]string `json:"public_keys"`
		Hostname            string            `json:"hostname"`
		NetworkConfig       struct {
			ContentPath string `json:"content_path"`
		} `json:"network_config"`
	}
	if err := json.Unmarshal([]byte(contents), &metadata); err != nil {
		return nil, err
	}

	var cfg config.CloudConfig
	if len(metadata.SSHAuthorizedKeyMap) > 0 {
		cfg.SSHAuthorizedKeys = make([]string, 0, len(metadata.SSHAuthorizedKeyMap))
		for _, name := range sortedKeys(metadata.SSHAuthorizedKeyMap) {
			cfg.SSHAuthorizedKeys = append(cfg.SSHAuthorizedKeys, metadata.SSHAuthorizedKeyMap[name])
		}
	}
	cfg.Hostname = metadata.Hostname
	cfg.NetworkConfigPath = metadata.NetworkConfig.ContentPath
	return &cfg, nil
}

// ExtractIPsFromMetaData parses a JSON blob in the OpenStack metadata service
// format and returns a substitution map possibly containing private_ipv4,
// public_ipv4, private_ipv6, and public_ipv6 addresses.
func ExtractIPsFromMetadata(contents []byte) (map[string]string, error) {
	var ips struct {
		PublicIPv4  string `json:"public-ipv4"`
		PrivateIPv4 string `json:"local-ipv4"`
		PublicIPv6  string `json:"public-ipv6"`
		PrivateIPv6 string `json:"local-ipv6"`
	}
	if err := json.Unmarshal(contents, &ips); err != nil {
		return nil, err
	}
	m := make(map[string]string)
	if ips.PrivateIPv4 != "" {
		m["$private_ipv4"] = ips.PrivateIPv4
	}
	if ips.PublicIPv4 != "" {
		m["$public_ipv4"] = ips.PublicIPv4
	}
	if ips.PrivateIPv6 != "" {
		m["$private_ipv6"] = ips.PrivateIPv6
	}
	if ips.PublicIPv6 != "" {
		m["$public_ipv6"] = ips.PublicIPv6
	}
	return m, nil
}

func sortedKeys(m map[string]string) (keys []string) {
	for key := range m {
		keys = append(keys, key)
	}
	sort.Strings(keys)
	return
}