helm源码分析之create命令
发布一个k8s部署视频：https://edu.csdn.net/course/detail/26967
课程内容：各种k8s部署方式。包括minikube部署，kubeadm部署，kubeasz部署，rancher部署，k3s部署。包括开发测试环境部署k8s，和生产环境部署k8s。
腾讯课堂连接地址https://ke.qq.com/course/478827?taid=4373109931462251&tuin=ba64518
第二个视频发布 https://edu.csdn.net/course/detail/27109
腾讯课堂连接地址https://ke.qq.com/course/484107?tuin=ba64518
介绍主要的k8s资源的使用配置和命令。包括configmap，pod，service，replicaset，namespace，deployment，daemonset，ingress，pv，pvc，sc，role，rolebinding，clusterrole，clusterrolebinding，secret，serviceaccount，statefulset，job，cronjob，podDisruptionbudget，podSecurityPolicy,networkPolicy,resourceQuota，limitrange，endpoint，event，conponentstatus，node，apiservice，controllerRevision等。
第三个视频发布：https://edu.csdn.net/course/detail/27574
详细介绍helm命令，学习helm chart语法，编写helm chart。深入分析各项目源码，学习编写helm插件
第四个课程发布：https://edu.csdn.net/course/detail/28488
本课程将详细介绍k8s所有命令，以及命令的go源码分析，学习知其然，知其所以然
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type createOptions struct {//create结构体
starter string // --starter
name string
starterDir string
}func newCreateCmd(out io.Writer) *cobra.Command {//创建create命令
o := &createOptions{}//初始化结构体
cmd := &cobra.Command{//创建cobra命令
Use: "create NAME",
Short: "create a new chart with the given name",
Long: createDesc,
Args: require.ExactArgs(1),
RunE: func(cmd *cobra.Command, args []string) error {
o.name = args[0]//设置name
o.starterDir = helmpath.DataPath("starters")//设置starter目录
return o.run(out)//运行
},
}
cmd.Flags().StringVarP(&o.starter, "starter", "p", "", "The name or absolute path to Helm starter scaffold")//starter选项
return cmd
}func (o *createOptions) run(out io.Writer) error {//运行
fmt.Fprintf(out, "Creating %s\n", o.name)//打印
chartname := filepath.Base(o.name)//获取chart名称
cfile := &chart.Metadata{//构造chart元数据
Name: chartname,
Description: "A Helm chart for Kubernetes",
Type: "application",
Version: "0.1.0",
AppVersion: "0.1.0",
APIVersion: chart.APIVersionV2,
}
if o.starter != "" {//如果starter不为空
// Create from the starter
lstarter := filepath.Join(o.starterDir, o.starter)//获取starter路径
// If path is absolute, we don't want to prefix it with helm starters folder
if filepath.IsAbs(o.starter) {//如果是绝对路径，设置lstarter
lstarter = o.starter
}
return chartutil.CreateFrom(cfile, filepath.Dir(o.name), lstarter)//从starter创建chart
}
_, err := chartutil.Create(chartname, filepath.Dir(o.name))//创建chart
return err
}//从starter创建chart
func CreateFrom(chartfile *chart.Metadata, dest, src string) error {
schart, err := loader.Load(src)//加载starter chart
if err != nil {
return errors.Wrapf(err, "could not load %s", src)
}
schart.Metadata = chartfile//设置chart元数据
var updatedTemplates []*chart.File
for _, template := range schart.Templates {//遍历templates
newData := transform(string(template.Data), schart.Name())//转换template chart名称
updatedTemplates = append(updatedTemplates, &chart.File{Name: template.Name, Data: newData})
}
schart.Templates = updatedTemplates//设置templates
b, err := yaml.Marshal(schart.Values)//把values转换成yaml
if err != nil {
return errors.Wrap(err, "reading values file")
}
var m map[string]interface{}
if err := yaml.Unmarshal(transform(string(b), schart.Name()), &m); err != nil {//转换values里的chart名称，然后转成map
return errors.Wrap(err, "transforming values file")
}
schart.Values = m//设置values
// SaveDir looks for the file values.yaml when saving rather than the values
// key in order to preserve the comments in the YAML. The name placeholder
// needs to be replaced on that file.
for _, f := range schart.Raw {//遍历chart文件
if f.Name == ValuesfileName {
f.Data = transform(string(f.Data), schart.Name())//转换文件中chart的名称
}
}
return SaveDir(schart, dest)//保存chart
}func Create(name, dir string) (string, error) {//创建chart
path, err := filepath.Abs(dir)//获取chart绝对路径
if err != nil {
return path, err
}
if fi, err := os.Stat(path); err != nil {//判断路径是否存在
return path, err
} else if !fi.IsDir() {//判断路径是否是目录
return path, errors.Errorf("no such directory %s", path)
}
cdir := filepath.Join(path, name)//获取chart目录
if fi, err := os.Stat(cdir); err == nil && !fi.IsDir() {//判断chart目录是否存在并且是目录
return cdir, errors.Errorf("file %s already exists and is not a directory", cdir)
}
files := []struct {//设置要生成的chart文件
path string
content []byte
}{
{
// Chart.yaml
path: filepath.Join(cdir, ChartfileName),
content: []byte(fmt.Sprintf(defaultChartfile, name)),
},
{
// values.yaml
path: filepath.Join(cdir, ValuesfileName),
content: []byte(fmt.Sprintf(defaultValues, name)),
},
{
// .helmignore
path: filepath.Join(cdir, IgnorefileName),
content: []byte(defaultIgnore),
},
{
// ingress.yaml
path: filepath.Join(cdir, IngressFileName),
content: transform(defaultIngress, name),
},
{
// deployment.yaml
path: filepath.Join(cdir, DeploymentName),
content: transform(defaultDeployment, name),
},
{
// service.yaml
path: filepath.Join(cdir, ServiceName),
content: transform(defaultService, name),
},
{
// serviceaccount.yaml
path: filepath.Join(cdir, ServiceAccountName),
content: transform(defaultServiceAccount, name),
},
{
// NOTES.txt
path: filepath.Join(cdir, NotesName),
content: transform(defaultNotes, name),
},
{
// _helpers.tpl
path: filepath.Join(cdir, HelpersName),
content: transform(defaultHelpers, name),
},
{
// test-connection.yaml
path: filepath.Join(cdir, TestConnectionName),
content: transform(defaultTestConnection, name),
},
}
for _, file := range files {//遍历文件
if _, err := os.Stat(file.path); err == nil {//如果文件存在则跳过
// File exists and is okay. Skip it.
continue
}
if err := writeFile(file.path, file.content); err != nil {//写入文件到磁盘
return cdir, err
}
}
// Need to add the ChartsDir explicitly as it does not contain any file OOTB
if err := os.MkdirAll(filepath.Join(cdir, ChartsDir), 0755); err != nil {//添加charts目录
return cdir, err
}
return cdir, nil
}