# 如何阅读k8s源码 本篇文章主要介绍了如何在windows下通过goland阅读k8s源码。 ## 下载及idea加载GO代码 这边大家可以百度一下，搜一下go的下载及破解版goland的下载，网上教程很多，按照顺序按照下载即可。我这里的版本如下 go: 1.15 goland: 2020.1 ``` C:\Users\nieweixing>go version go version go1.15 windows/amd64 ``` ![upload-image](/files/-MN2J7cgzHj7D9T76cJS) ### 从github上克隆源码到本地 首先创建一个gopath目录,我们这里用的是 ``` D:\go-code ``` 然后在go-code目录下创建一个src/k8s.io,最后我们存放代码的目录为 ``` D:\go-code\src\k8s.io ``` 我们切换到k8s.io目录，执行如下命令clone代码，注意需要加上core.symlinks=true这个参数，源码中有很多软连接，不加这个参数会找不到依赖。 ``` # 克隆最新代码 git clone -c core.symlinks=true https://github.com/kubernetes/kubernetes # 克隆某个分支代码 git clone -c core.symlinks=true -b xxxx https://github.com/kubernetes/kubernetes ``` ### goland查看源码并分析目录结构 我们打开goland后配置好$GOPATH,然后查看下对应源码即可。 ![upload-image](/files/-MN2J7ciQEbXOfiWJF77) 下面我们简单介绍下k8s源码目录的作用 ``` |--api // 存放api规范相关的文档 |------api-rules //已经存在的违反Api规范的api |------openapi-spec //OpenApi规范 |--build // 构建和测试脚本 |------run.sh //在容器中运行该脚本，后面可接多个命令：make, make cross 等 |------copy-output.sh //把容器中_output/dockerized/bin目录下的文件拷贝到本地目录 |------make-clean.sh //清理容器中和本地的_output目录 |------shell.sh // 容器中启动一个shell终端 |------...... |--cluster // 自动创建和配置kubernetes集群的脚本，包括networking, DNS, nodes等 |--cmd // 内部包含各个组件的入口，具体核心的实现部分在pkg目录下 |--hack // 编译、构建及校验的工具类 |--logo // kubernetes的logo |--pkg // 主要代码存放类，后面会详细补充该目录下内容 |------kubeapiserver |------kubectl |------kubelet |------proxy |------registry |------scheduler |------security |------watch |------...... |--plugin |------pkg/admission //认证 |------pkg/auth //鉴权 |--staging // 这里的代码都存放在独立的repo中，以引用包的方式添加到项目中 |------k8s.io/api |------k8s.io/apiextensions-apiserver |------k8s.io/apimachinery |------k8s.io/apiserver |------k8s.io/client-go |------...... |--test //测试代码 |--third_party //第三方代码，protobuf、golang-reflect等 |--translations //不同国家的语言包，使用poedit查看及编辑 ``` ## Kubernetes源码编译 我们知道k8s的运行访问有2种方式，一种是二进制，还有一种就是docker镜像的方式，下面我们来讲一下如何将源码编译成二进制和镜像的方式。 ### 二进制编译kubernetes #### 编译全部组件 这里我们以在centos7上作为示例 ``` # yum install go -y # mkdir -p /root/go/src/k8s.io # git clone https://github.com/kubernetes/kubernetes # cd /root/go/src/k8s.io/kubernetes # KUBE_BUILD_PLATFORMS=linux/amd64 make ``` 在这里我们编译apiserver的时候会出现一个错误，提示我们app\server.go:477:70: undefined: "k8s.io/kubernetes/pkg/generated/openapi".GetOpenAPIDefinitions。 在pkg/generated/openapi确实没有这个函数。这个函数是在zz\_generated.openapi.go，我们需要在/root/go/src/k8s.io/kubernetes下执行 ``` # cd /root/go/src/k8s.io/kubernetes # make generated_files # ls -l pkg/generated/openapi total 2384 -rw-r--r-- 1 root root 1216 Nov 23 11:23 BUILD -rw-r--r-- 1 root root 621 Nov 23 11:23 doc.go -rw-r--r-- 1 root root 1533 Nov 23 11:23 openapi_test.go -rw-r--r-- 1 root root 131 Nov 23 11:23 OWNERS -rw-r--r-- 1 root root 2423572 Nov 23 12:41 zz_generated.openapi.go ``` 这里我们发现已经zz\_generated.openapi.go生成在pkg/generated/openapi目录下，如果你在windows也有代码，那么你可以把这个文件拷贝到对应目录下。 现在我们再执行编译命令，然后编译好的二进制文件在/root/go/src/k8s.io/kubernetes/\_output/bin这个目录下 ``` [root@VM-0-13-centos kubernetes]# KUBE_BUILD_PLATFORMS=linux/amd64 make +++ [1123 13:45:25] Building go targets for linux/amd64: cmd/kube-proxy cmd/kube-apiserver cmd/kube-controller-manager cmd/kubelet cmd/kubeadm cmd/kube-scheduler vendor/k8s.io/kube-aggregator vendor/k8s.io/apiextensions-apiserver cluster/gce/gci/mounter cmd/kubectl cmd/gendocs cmd/genkubedocs cmd/genman cmd/genyaml cmd/genswaggertypedocs cmd/linkcheck vendor/github.com/onsi/ginkgo/ginkgo test/e2e/e2e.test cluster/images/conformance/go-runner cmd/kubemark vendor/github.com/onsi/ginkgo/ginkgo test/e2e_node/e2e_node.test [root@VM-0-13-centos kubernetes]# ls _output/bin apiextensions-apiserver e2e_node.test genman go2make kube-aggregator kubelet linkcheck conversion-gen e2e.test genswaggertypedocs go-bindata kube-apiserver kubemark mounter deepcopy-gen gendocs genyaml go-runner kube-controller-manager kube-proxy openapi-gen defaulter-gen genkubedocs ginkgo kubeadm kubectl kube-scheduler prerelease-lifecycle-gen ``` #### 编译单个组件 我们可以只编译某一个组件，下面我们来演示如何只编译kubelet的二进制文件 在linux和window下都是同样的方式，只是编译的平台不一样，生成的二进制文件不一样，window下生产kubelet.exe,linux下生产kubelet这个二进制执行文件 ``` # cd $GOPATH/src/k8s.io/kubernetes/cmd/kubelet # go build -v ``` 执行编译完成后，在kubelet目录下会存在可执行的kubelet二进制文件 ![upload-image](/files/-MN2J7ckWTZiIkZgYMJG) ![upload-image](/files/-MN2J7clKgld-PBtSFn_) ### docker镜像编译kubernetes 我们这里下载的是最新的源码，如果拉取不到国外镜像，可以执行下面命令拉取镜像然后上传到本地机器 ``` docker pull mirrorgooglecontainers/pause-amd64:3.1 docker pull zhuyuhua/kube-cross:v1.15.2-1 docker pull mirrorgooglecontainers/debian-base-amd64:0.4.0 docker pull mirrorgooglecontainers/debian-iptables-amd64:v11.0 docker pull mirrorgooglecontainers/debian-hyperkube-base-amd64:0.12.0 docker pull litmuschaos/go-runner:latest docker tag mirrorgooglecontainers/pause-amd64:3.1 k8s.gcr.io/build-image/pause-amd64:3.1 docker tag zhuyuhua/kube-cross:v1.15.2-1 k8s.gcr.io/build-image/kube-cross:v1.15.2-1 docker tag mirrorgooglecontainers/debian-base-amd64:0.4.0 k8s.gcr.io/build-image/debian-base-amd64:0.4.0 docker tag mirrorgooglecontainers/debian-iptables-amd64:v11.0 k8s.gcr.io/build-image/debian-iptables:buster-v1.3.0 docker tag mirrorgooglecontainers/debian-hyperkube-base-amd64:0.12.0 k8s.gcr.io/build-image/debian-hyperkube-base-amd64:0.12.0 docker tag litmuschaos/go-runner:latest k8s.gcr.io/build-image/go-runner:buster-v2.0.1 ``` 为了防止从远程拉取镜像，我们可以修改下$GOPATH\src\k8s.io\kubernetes\build\lib\release.sh的配置 ``` "${DOCKER[@]}" build ${docker_build_opts:+"${docker_build_opts}"} -q -t "${docker_image_tag}" "${docker_build_path}" >/dev/null 改成如下 "${DOCKER[@]}" build -q -t "${docker_image_tag}" "${docker_build_path}" >/dev/null ``` 然后执行如下命令进行打包 ``` [root@VM-0-3-centos kubernetes]# KUBE_GIT_VERSION=v1.19.0-alpha.0 KUBE_FASTBUILD=true KUBE_BUILD_PULL_LATEST_IMAGES=n make release-images +++ [1123 17:20:07] Verifying Prerequisites.... +++ [1123 17:20:07] Building Docker image kube-build:build-a3ee5ddec9-5-v1.15.2-1 +++ [1123 17:20:10] Syncing sources to container +++ [1123 17:20:13] Running build command... +++ [1123 17:21:01] Building go targets for linux/amd64: cmd/kube-apiserver cmd/kube-controller-manager cmd/kube-scheduler cmd/kube-proxy vendor/github.com/onsi/ginkgo/ginkgo test/e2e/e2e.test cluster/images/conformance/go-runner cmd/kubectl +++ [1123 17:21:42] Syncing out of container +++ [1123 17:21:51] Building images: linux-amd64 +++ [1123 17:21:51] Starting docker build for image: kube-apiserver-amd64 +++ [1123 17:21:51] Starting docker build for image: kube-controller-manager-amd64 +++ [1123 17:21:51] Starting docker build for image: kube-scheduler-amd64 +++ [1123 17:21:51] Starting docker build for image: kube-proxy-amd64 +++ [1123 17:21:51] Building conformance image for arch: amd64 +++ [1123 17:22:26] Deleting docker image k8s.gcr.io/kube-proxy-amd64:v1.19.0-alpha.0 +++ [1123 17:22:30] Deleting docker image k8s.gcr.io/kube-scheduler-amd64:v1.19.0-alpha.0 +++ [1123 17:22:37] Deleting docker image k8s.gcr.io/kube-apiserver-amd64:v1.19.0-alpha.0 +++ [1123 17:22:37] Deleting docker image k8s.gcr.io/kube-controller-manager-amd64:v1.19.0-alpha.0 +++ [1123 17:22:51] Deleting conformance image k8s.gcr.io/conformance-amd64:v1.19.0-alpha.0 +++ [1123 17:22:51] Docker builds done ``` 编译完成后,可以到对应的目录下查找镜像，并通过docker load < *\** 来加载镜像,然后通过修改组件的yaml的镜像名称即可。 ``` [root@VM-0-3-centos amd64]# ll total 2101008 -rw-r--r-- 1 root root 298798080 Nov 23 17:22 conformance-amd64.tar -rw------- 2 root root 619204608 Nov 23 17:22 kube-apiserver.tar -rw------- 2 root root 612844544 Nov 23 17:22 kube-controller-manager.tar -rw------- 2 root root 103392256 Nov 23 17:22 kube-proxy.tar -rw------- 2 root root 517171712 Nov 23 17:22 kube-scheduler.tar [root@VM-0-3-centos amd64]# pwd /root/go/src/k8s.io/kubernetes/_output/release-images/amd64 [root@VM-0-3-centos amd64]# docker load < kube-apiserver.tar 5eebc1b5676b: Loading layer [==================================================>] 163.4MB/163.4MB Loaded image: k8s.gcr.io/kube-apiserver-amd64:v1.19.0-alpha.0 [root@VM-0-3-centos amd64]# docker images|grep apis k8s.gcr.io/kube-apiserver-amd64 v1.19.0-alpha.0 c1ac6c895896 20 minutes ago 613MB ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.niewx.cn/20201111-ru-he-yue-du-k8s-yuan-ma.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.