【kubernetes/k8s源码分析】 kubernetes csi external-resizer 源码分析

忘是亡心i 2021-12-16 05:41 298阅读 0赞

**Git Repository:** [https://github.com/kubernetes-csi/external-resizer][https_github.com_kubernetes-csi_external-resizer]

**Status:** Alpha

<table> 
 <thead> 
  <tr> 
   <th>Latest release</th> 
   <th>Branch</th> 
   <th>Min CSI Version</th> 
   <th>Max CSI Version</th> 
   <th>Container Image</th> 
   <th>Min K8s Version</th> 
   <th>Max K8s Version</th> 
   <th>Recommended K8s Version</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td><a href="https://github.com/kubernetes-csi/external-resizer/tree/v0.2.0" rel="nofollow">external-resizer v0.2.0</a></td> 
   <td><a href="https://github.com/kubernetes-csi/external-resizer/tree/master" rel="nofollow">master</a></td> 
   <td><a href="https://github.com/container-storage-interface/spec/releases/tag/v1.1.0" rel="nofollow">v1.1.0</a></td> 
   <td>-</td> 
   <td>quay.io/k8scsi/csi-resizer:v0.2.0</td> 
   <td>v1.15</td> 
   <td>-</td> 
   <td>v1.15</td> 
  </tr> 
  <tr> 
   <td><a href="https://github.com/kubernetes-csi/external-resizer/tree/v0.1.0" rel="nofollow">external-resizer v0.1.0</a></td> 
   <td><a href="https://github.com/kubernetes-csi/external-resizer/tree/master" rel="nofollow">master</a></td> 
   <td><a href="https://github.com/container-storage-interface/spec/releases/tag/v1.1.0" rel="nofollow">v1.1.0</a></td> 
   <td>-</td> 
   <td>quay.io/k8scsi/csi-resizer:v0.1.0</td> 
   <td>v1.14</td> 
   <td>v1.14</td> 
   <td>v1.14</td> 
  </tr> 
 </tbody> 
</table>

### 默认命令行 ###

/csi-resizer --v=5 --csi-address=/var/lib/csi/sockets/pluginproxy/mock.socket

# 1. NewResizer 函数 #

csi.New 建立GRPC 连接

// NewResizer creates a new resizer responsible for resizing CSI volumes.
    func NewResizer(
    	address string,
    	timeout time.Duration,
    	k8sClient kubernetes.Interface,
    	informerFactory informers.SharedInformerFactory) (Resizer, error) {
    	csiClient, err := csi.New(address, timeout)
    	if err != nil {
    		return nil, err
    	}
    	return NewResizerFromClient(csiClient, timeout, k8sClient, informerFactory)
    }

###    1.1 NewResizerFromClient 函数 ###

func NewResizerFromClient(
    	csiClient csi.Client,
    	timeout time.Duration,
    	k8sClient kubernetes.Interface,
    	informerFactory informers.SharedInformerFactory) (Resizer, error) {
    	driverName, err := getDriverName(csiClient, timeout)
    	if err != nil {
    		return nil, fmt.Errorf("get driver name failed: %v", err)
    	}

**    1.1.1 插件是否支持 controller service**

是否 controller 设置能力 PluginCapability\_Service\_CONTROLLER\_SERVICE

supportControllerService, err := supportsPluginControllerService(csiClient, timeout)
    if err != nil {
    	return nil, fmt.Errorf("failed to check if plugin supports controller service: %v", err)
    }
    
    if !supportControllerService {
    	return nil, controllerServiceNotSupportErr
    }

**    1.1.2 controller 是否有能力 resize**

主要时插件是否设置了能力 ControllerServiceCapability\_RPC\_EXPAND\_VOLUME

如果 contoller 没有设置能力，试试看 node 是否设置了能力

supportControllerResize, err := supportsControllerResize(csiClient, timeout)
    	if err != nil {
    		return nil, fmt.Errorf("failed to check if plugin supports controller resize: %v", err)
    	}
    
    	if !supportControllerResize {
    		supportsNodeResize, err := supportsNodeResize(csiClient, timeout)
    		if err != nil {
    			return nil, fmt.Errorf("failed to check if plugin supports node resize: %v", err)
    		}
    		if supportsNodeResize {
    			klog.Info("The CSI driver supports node resize only, using trivial resizer to handle resize requests")
    			return newTrivialResizer(driverName), nil
    		}
    		return nil, resizeNotSupportErr
    	}

[https_github.com_kubernetes-csi_external-resizer]: https://github.com/kubernetes-csi/external-resizer