github.com/alibaba/sealer@v0.8.6-0.20220430115802-37a2bdaa8173/pkg/plugin/plugins.go (about)

     1  // Copyright © 2021 Alibaba Group Holding Ltd.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package plugin
    16  
    17  import (
    18  	"fmt"
    19  	"io/ioutil"
    20  	"os"
    21  	"path/filepath"
    22  	"plugin"
    23  	"strings"
    24  
    25  	"github.com/alibaba/sealer/utils/platform"
    26  
    27  	"github.com/alibaba/sealer/common"
    28  	v1 "github.com/alibaba/sealer/types/api/v1"
    29  	v2 "github.com/alibaba/sealer/types/api/v2"
    30  	"github.com/alibaba/sealer/utils"
    31  )
    32  
    33  type InvalidPluginTypeError struct {
    34  	Name string
    35  }
    36  
    37  func (err InvalidPluginTypeError) Error() string {
    38  	return fmt.Sprintf("plugin type not registered: %s", err.Name)
    39  }
    40  
    41  type Plugins interface {
    42  	Load() error
    43  	Run(host []string, phase Phase) error
    44  }
    45  
    46  // PluginsProcessor : process two list: plugin config list and embed pluginFactories that contains plugin interface.
    47  type PluginsProcessor struct {
    48  	// plugin config list
    49  	Plugins []v1.Plugin
    50  	Cluster *v2.Cluster
    51  }
    52  
    53  //plugins form Clusterfile
    54  func NewPlugins(cluster *v2.Cluster, plugins []v1.Plugin) Plugins {
    55  	return &PluginsProcessor{
    56  		Cluster: cluster,
    57  		Plugins: plugins,
    58  	}
    59  }
    60  
    61  // Load plugin configs and shared object(.so) file from $mountRootfs/plugins dir.
    62  func (c *PluginsProcessor) Load() error {
    63  	path := filepath.Join(platform.DefaultMountCloudImageDir(c.Cluster.Name), "plugins")
    64  	_, err := os.Stat(path)
    65  	if os.IsNotExist(err) {
    66  		return nil
    67  	}
    68  
    69  	files, err := ioutil.ReadDir(path)
    70  	if err != nil {
    71  		return fmt.Errorf("failed to load plugin dir %v", err)
    72  	}
    73  	for _, f := range files {
    74  		// load shared object(.so) file
    75  		if filepath.Ext(f.Name()) == ".so" {
    76  			soFile := filepath.Join(common.DefaultTheClusterRootfsPluginDir(c.Cluster.Name), f.Name())
    77  			p, pt, err := c.loadOutOfTree(soFile)
    78  			if err != nil {
    79  				return err
    80  			}
    81  			Register(pt, p)
    82  		}
    83  		if utils.YamlMatcher(f.Name()) {
    84  			plugins, err := utils.DecodePlugins(filepath.Join(path, f.Name()))
    85  			if err != nil {
    86  				return fmt.Errorf("failed to load plugin %v", err)
    87  			}
    88  			c.Plugins = append(c.Plugins, plugins...)
    89  		}
    90  	}
    91  	return nil
    92  }
    93  
    94  // Run execute each in-tree or out-of-tree plugin by traversing the plugin list.
    95  func (c *PluginsProcessor) Run(host []string, phase Phase) error {
    96  	for _, plugin := range c.Plugins {
    97  		if utils.NotIn(string(phase), strings.Split(plugin.Spec.Action, "|")) {
    98  			continue
    99  		}
   100  		p, ok := pluginFactories[plugin.Spec.Type]
   101  		// if we use cluster file dump plugin config,some plugin load after mount rootfs,
   102  		// we still need to return those not find error.
   103  		// apply module to judged whether to show errors.
   104  		if !ok {
   105  			return InvalidPluginTypeError{plugin.Spec.Type}
   106  		}
   107  		// #nosec
   108  		err := p.Run(Context{Cluster: c.Cluster, Host: host, Plugin: &plugin}, phase)
   109  		if err != nil {
   110  			return fmt.Errorf("failed to run plugin %s: %v", plugin.Name, err)
   111  		}
   112  	}
   113  	return nil
   114  }
   115  
   116  func (c *PluginsProcessor) loadOutOfTree(soFile string) (Interface, string, error) {
   117  	plug, err := plugin.Open(soFile)
   118  	if err != nil {
   119  		return nil, "", err
   120  	}
   121  	//look up the exposed variable named `Plugin`
   122  	symbol, err := plug.Lookup(Plugin)
   123  	if err != nil {
   124  		return nil, "", err
   125  	}
   126  
   127  	p, ok := symbol.(Interface)
   128  	if !ok {
   129  		return nil, "", fmt.Errorf("failed to find Plugin symbol")
   130  	}
   131  
   132  	//look up the exposed variable named `PluginType`
   133  	pts, err := plug.Lookup(PluginType)
   134  	if err != nil {
   135  		return nil, "", err
   136  	}
   137  
   138  	pt, ok := pts.(*string)
   139  	if !ok {
   140  		return nil, "", fmt.Errorf("failed to find PluginType symbol")
   141  	}
   142  	return p, *pt, nil
   143  }