Mirantis/virtlet

/*
Copyright 2017 Mirantis

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 libvirttools

import (
    "encoding/base64"
    "fmt"
    "strings"

    // use this instead of "gopkg.in/yaml.v2" so we don't get
    // map[interface{}]interface{} when unmarshalling cloud-init data
    "github.com/ghodss/yaml"
    meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    "k8s.io/client-go/kubernetes"

    "github.com/Mirantis/virtlet/pkg/metadata/types"
    "github.com/Mirantis/virtlet/pkg/utils"
)

func init() {
    types.SetExternalDataLoader(&defaultExternalDataLoader{})
}

type defaultExternalDataLoader struct {
    kubeClient kubernetes.Interface
}

var _ types.ExternalDataLoader = &defaultExternalDataLoader{}

// LoadCloudInitData implements LoadCloudInitData method of ExternalDataLoader interface.
func (l *defaultExternalDataLoader) LoadCloudInitData(va *types.VirtletAnnotations, namespace string, podAnnotations map[string]string) error {
    if namespace == "" {
        return nil
    }
    var err error
    userDataSourceKey := podAnnotations[types.CloudInitUserDataSourceKeyName]
    sshKeySourceKey := podAnnotations[types.SSHKeySourceKeyName]
    if userDataSourceKey != "" {
        err = l.loadUserDataFromDataSource(va, namespace, userDataSourceKey)
        if err != nil {
            return err
        }
    }
    if sshKeySourceKey != "" {
        err = l.loadSSHKeysFromDataSource(va, namespace, sshKeySourceKey)
        if err != nil {
            return err
        }
    }
    return nil
}

// LoadFileMap implements LoadFileMap method of ExternalDataLoader interface.
func (l *defaultExternalDataLoader) LoadFileMap(namespace, dsSpec string) (map[string][]byte, error) {
    if namespace == "" {
        return nil, nil
    }
    parts := strings.Split(dsSpec, "/")
    if len(parts) != 2 {
        return nil, fmt.Errorf("invalid %q annotation format. Expected kind/name, but insted got %q", types.FilesFromDSKeyName, dsSpec)
    }

    data, err := l.readK8sKeySource(parts[0], parts[1], namespace, "")
    if err != nil {
        return nil, err
    }

    return parseDataAsFileMap(data)
}

func (l *defaultExternalDataLoader) loadUserDataFromDataSource(va *types.VirtletAnnotations, namespace, key string) error {
    parts := strings.Split(key, "/")
    if len(parts) != 2 {
        return fmt.Errorf("invalid %q annotation format. Expected kind/name, but insted got %s", types.CloudInitUserDataSourceKeyName, key)
    }
    ud, err := l.readK8sKeySource(parts[0], parts[1], namespace, "")
    if err != nil {
        return err
    }
    va.UserData = map[string]interface{}{}
    for k, v := range ud {
        var value interface{}
        if yaml.Unmarshal([]byte(v), &value) == nil {
            va.UserData[k] = value
        }
    }
    return nil
}

func (l *defaultExternalDataLoader) loadSSHKeysFromDataSource(va *types.VirtletAnnotations, namespace, key string) error {
    parts := strings.Split(key, "/")
    if len(parts) != 2 && len(parts) != 3 {
        return fmt.Errorf("invalid %s annotation format. Expected kind/name[/key], but insted got %s", types.SSHKeySourceKeyName, key)
    }
    dataKey := "authorized_keys"
    if len(parts) == 3 {
        dataKey = parts[2]
    }
    ud, err := l.readK8sKeySource(parts[0], parts[1], namespace, dataKey)
    if err != nil {
        return err
    }
    sshKeys := ud[dataKey]
    keys := strings.Split(sshKeys, "\n")
    for _, k := range keys {
        k = strings.TrimSpace(k)
        if k != "" {
            va.SSHKeys = append(va.SSHKeys, k)
        }
    }
    return nil
}

func (l *defaultExternalDataLoader) ensureKubeClient() error {
    if l.kubeClient == nil {
        var err error
        l.kubeClient, err = utils.GetK8sClientset(nil)
        if err != nil {
            return err
        }
    }
    return nil
}

func (l *defaultExternalDataLoader) readK8sKeySource(sourceType, sourceName, namespace, key string) (map[string]string, error) {
    if err := l.ensureKubeClient(); err != nil {
        return nil, err
    }
    sourceType = strings.ToLower(sourceType)
    switch sourceType {
    case "secret":
        secret, err := l.kubeClient.CoreV1().Secrets(namespace).Get(sourceName, meta_v1.GetOptions{})
        if err != nil {
            return nil, err
        }
        if key != "" {
            return map[string]string{key: string(secret.Data[key])}, nil
        }
        result := map[string]string{}
        for k, v := range secret.Data {
            result[k] = string(v)
        }
        return result, nil
    case "configmap":
        configmap, err := l.kubeClient.CoreV1().ConfigMaps(namespace).Get(sourceName, meta_v1.GetOptions{})
        if err != nil {
            return nil, err
        }
        if key != "" {
            return map[string]string{key: configmap.Data[key]}, nil
        }
        result := map[string]string{}
        for k, v := range configmap.Data {
            result[k] = v
        }
        return result, nil
    default:
        return nil, fmt.Errorf("unsupported source kind %s. Must be one of (secret, configmap)", sourceType)
    }
}

func parseDataAsFileMap(data map[string]string) (map[string][]byte, error) {
    files := make(map[string][]byte)
    for k, v := range data {
        if strings.HasSuffix(k, "_path") || strings.HasSuffix(k, "_encoding") {
            continue
        }

        path, pOk := data[k+"_path"]
        if !pOk {
            return nil, fmt.Errorf("missing path for %q entry", k)
        }

        encoding, eOk := data[k+"_encoding"]
        if !eOk {
            encoding = "base64"
        }

        switch encoding {
        case "plain":
            files[path] = []byte(v)
        case "base64":
            data, err := base64.StdEncoding.DecodeString(v)
            if err != nil {
                return nil, fmt.Errorf("cannot decode data under %q key as base64 encoded: %v", k, err)
            }
            files[path] = data
        default:
            return nil, fmt.Errorf("unkonwn encoding %q for %q", encoding, k)
        }
    }
    return files, nil
}