K8s Source Analysis------Third Party library ETCD client Analysis

This blog from my space reproduced over, http://user.qzone.qq.com/29185807/blog/1458542207 Code is GITHUB.COM/COREOS/GO-ETCD/ETCD Note: This version is the ETCD client used in k8s v1.1.1. First I look at how the next k8s is used. Location in K8s.io\kubernetes\cmd\kube-apiserver\app\server.go Code directory, from this point of view, the code is very clear So we're going to go in here, see Client.go. First look at the structural body Inside the structure, the more important things 1, cluster, cluster management 2, HttpClient, this will be the final entrance. We continue to This is mainly the initialization of the Cluster,httpclient Which cluster back in detail, here we continue to see HttpClient It's clear that this is where the client in a standard library net/http is constructed. The approximate initialization is simple. There is actually an initialization of TLS. For Newtlsclient, the corresponding httpclient is initialized to Inithttpsclient Let's take a look at what the ETCD client has provided those operations. Get operation Let's see Get.go. Obviously, we saw that get called Rawget, and Rawget called the Get We're going to track get In the Request.go Keep Getcancelable. or in a request.go. Mainly have newrawrequest. In Request.go In fact, some of the packaging of request, including some parameters We continue to watch SendRequest. This is the core of the entire code. Here we see that when the cancel in Rawrequest is not nil, a coprocessor is initiated to receive the cancel message. But the current analysis of get is not set We continue to have a for loop, attempt for the number of attempts, and, if successful, Exit For loop, and the failure will continue. which has a variable of httppath is a key We're going to go in there and see Requet.go. We've seen cluster, and we're going to go in and see. From the above cluster code to see in fact pick is to return to the cluster in a host, and pick machine is a random host, in the initialization of a random, in the failure time, will be again random We go back to the sendrequest. The main place here is to construct a request in a standard library net/http and continue We see the httpclient we mentioned earlier, receive the request just built, and do. is to initiate an HTTP request. Check the head and, if it is normal, exit the For loop After exiting the For loop, a rawresponse structure is returned Finally we return to We saw the results. is actually a decoding process. The get operation is resolved There are also some operations such as: Addchilddir In fact, tracking in, and finally to the SendRequest function There are other operations that are not introduced, and the process of its code is basically consistent. Hao Haohua QQ Crescent moon Lonely Road length 29185807 March 21, 2016 (Copyright: This article is original for the author, if you need to reprint, please notify me, and indicate the source and author. Reproduced without authorization, reserve the right to pursue its infringement. ）