在近程机器上启动集群，而后在本地机器上，通过IDE近程调试kubernetes的代码。
以apiserver为例。
一.环境筹备(近程机器)
1. 环境
- OS: centos7.6
- kubernetes源码：v1.20
- golang: go1.17.12
- dlv: 1.9.1
2. 装置golang
参考：https://docs.studygolang.com/doc/install
3. 装置dlv
参考：https://github.com/go-delve/delve/tree/master/Documentation/installation
# go install github.com/go-delve/delve/cmd/dlv@latest4. 下载kubernetes源码
git clone -b release-1.20 git@github.com:kubernetes/kubernetes.git二.批改编译参数（近程机器）
进入到kubernetes的源码，批改hack/lib/golang.sh文件，从而让编译器不去优化掉debug的信息，次要包含：
- 禁止-w -s，保留文件名、行号；
- 加上-gcflags=”all=-N -l”，禁止优化和内联；
批改点：
kube::golang::build_binaries() {
# Create a sub-shell so that we don't pollute the outer environment
(
# Check for `go` binary and set ${GOPATH}.
kube::golang::setup_env
V=2 kube::log::info "Go version: $(GOFLAGS='' go version)"
local host_platform
host_platform=$(kube::golang::host_platform)
local goflags goldflags goasmflags gogcflags gotags
# If GOLDFLAGS is unset, then set it to the a default of "-s -w".
# Disable SC2153 for this, as it will throw a warning that the local
# variable goldflags will exist, and it suggest changing it to this.
# shellcheck disable=SC2153
# goldflags="${GOLDFLAGS=-s -w -buildid=} $(kube::version::ldflags)"
goldflags="${GOLDFLAGS=-buildid=} $(kube::version::ldflags)" // 去掉-s -w
goasmflags="-trimpath=${KUBE_ROOT}"
gogcflags="${GOGCFLAGS:-} -trimpath=${KUBE_ROOT}"
gogcflags="${gogcflags} -N -l" // 减少-N -l
# extract tags if any specified in GOFLAGS
# shellcheck disable=SC2001
gotags="selinux,notest,$(echo "${GOFLAGS:-}" | sed -e 's|.*-tags=\([^-]*\).*|\1|')"
local -a targets=()
local arg
...
}三. 装置etcd（近程机器）
进入kubernetes的源码，执行以下脚本，装置etcd:
# ./hack/install-etcd.sh
Downloading https://github.com/coreos/etcd/releases/download/v3.4.13/etcd-v3.4.13-linux-amd64.tar.gz succeed
etcd v3.4.13 installed. To use:
export PATH="/root/go/src/github.com/kubernetes/kubernetes/third_party/etcd:${PATH}"四. 启动本地集群（近程机器）
筹备工作实现后，执行上面的脚本，启动本地集群：
# ./hack/local-up-cluster.sh查看kube过程是否启动：
# ps -a|grep kube
18999 pts/0 00:26:51 kube-controller
19001 pts/0 00:02:55 kube-scheduler
19162 pts/0 00:26:35 kubelet
19929 pts/0 00:00:42 kube-proxy
89307 pts/2 00:00:07 kube-apiserverkubectl拜访本地集群：
# export KUBECONFIG=/var/run/kubernetes/admin.kubeconfig
# cluster/kubectl.sh get ns
NAME STATUS AGE
default Active 45m
kube-node-lease Active 45m
kube-public Active 45m
kube-system Active 45m五. dlv启动kube-apiserver（近程机器）
查看kube-apiserver的启动参数：
# ps -ef|grep kube-apiserver
root 89307 30528 12 09:37 pts/2 00:00:17 /root/go/src/github.com/kubernetes/kubernetes/_output/local/bin/linux/amd64/kube-apiserver --authorization-mode=Node,RBAC --cloud-provider= --cloud-config= --v=3 --vmodule= --audit-policy-file=/tmp/kube-audit-policy-file --audit-log-path=/tmp/kube-apiserver-audit.log --authorization-webhook-config-file= --authentication-token-webhook-config-file= --cert-dir=/var/run/kubernetes --client-ca-file=/var/run/kubernetes/client-ca.crt --kubelet-client-certificate=/var/run/kubernetes/client-kube-apiserver.crt --kubelet-client-key=/var/run/kubernetes/client-kube-apiserver.key --service-account-key-file=/tmp/kube-serviceaccount.key --service-account-lookup=true --service-account-issuer=https://kubernetes.default.svc --service-account-signing-key-file=/tmp/kube-serviceaccount.key --enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,Priority,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota --disable-admission-plugins= --admission-control-config-file= --bind-address=0.0.0.0 --secure-port=6443 --tls-cert-file=/var/run/kubernetes/serving kube-apiserver.crt --tls-private-key-file=/var/run/kubernetes/serving-kube-apiserver.key --storage-backend=etcd3 --storage-media-type=application/vnd.kubernetes.protobuf --etcd-servers=http://127.0.0.1:2379 --service-cluster-ip-range=10.0.0.0/24 --feature-gates=AllAlpha=false --external-hostname=localhost --requestheader-username-headers=X-Remote-User --requestheader-group-headers=X-Remote-Group --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-client-ca-file=/var/run/kubernetes/request-header-ca.crt --requestheader-allowed-names=system:auth-proxy --proxy-client-cert-file=/var/run/kubernetes/client-auth-proxy.crt --proxy-client-key-file=/var/run/kubernetes/client-auth-proxy.key --cors-allowed-origins=/127.0.0.1(:[0-9]+)?$,/localhost(:[0-9]+)?$杀掉kube-apiserver过程，应用dlv启动：
- dlv监听时，应用12345端口；
- 能够让Goland近程连贯该端口，进行近程debug；
# kill -9 89307
## 1. dlv --headless exec启动apiserver过程
## 2. 过程参数中，减少--listen=0.0.0.0:12345参数
# dlv --headless exec /root/go/src/github.com/kubernetes/kubernetes/_output/local/bin/linux/amd64/kube-apiserver --listen=0.0.0.0:12345 --api-version=2 --log -- --authorization-mode=Node,RBAC --cloud-provider= --cloud-config= --v=3 --vmodule= --audit-policy-file=/tmp/kube-audit-policy-file --audit-log-path=/tmp/kube-apiserver-audit.log --authorization-webhook-config-file= --authentication-token-webhook-config-file= --cert-dir=/var/run/kubernetes --client-ca-file=/var/run/kubernetes/client-ca.crt --kubelet-client-certificate=/var/run/kubernetes/client-kube-apiserver.crt --kubelet-client-key=/var/run/kubernetes/client-kube-apiserver.key --service-account-key-file=/tmp/kube-serviceaccount.key --service-account-lookup=true --service-account-issuer=https://kubernetes.default.svc --service-account-signing-key-file=/tmp/kube-serviceaccount.key --enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,Priority,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota --disable-admission-plugins= --admission-control-config-file= --bind-address=0.0.0.0 --secure-port=6443 --tls-cert-file=/var/run/kubernetes/serving-kube-apiserver.crt --tls-private-key-file=/var/run/kubernetes/serving-kube-apiserver.key --storage-backend=etcd3 --storage-media-type=application/vnd.kubernetes.protobuf --etcd-servers=http://127.0.0.1:2379 --service-cluster-ip-range=10.0.0.0/24 --feature-gates=AllAlpha=false --external-hostname=localhost --requestheader-username-headers=X-Remote-User --requestheader-group-headers=X-Remote-Group --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-client-ca-file=/var/run/kubernetes/request-header-ca.crt --requestheader-allowed-names=system:auth-proxy --proxy-client-cert-file=/var/run/kubernetes/client-auth-proxy.crt --proxy-client-key-file=/var/run/kubernetes/client-auth-proxy.key --cors-allowed-origins=/127.0.0.1\(:[0-9]+\)?$,/localhost\(:[0-9]+\)?$六. Goland近程调试（本地机器）
Goland上配置近程Debug的ip和端口:
Goland应用下面的配置，启动Debug:
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