Kubernetes Helm 把两个变量和中间的字符串结合起来

我试图改变一个变量的值，如果它设置的另一个变量通过组合两个在中间的破折号，我不知道这样做的语法，我想的是这样的东西:

{{- $serviceNamespace := .Values.serviceNamespace -}}
{{- $serviceTag := .Values.serviceTag -}}
{{- if $serviceTag}}
{{- $serviceNamespace := .Values.serviceNamespace  "-" .Values.serviceTag -}}
{{- end}}

这是正确的吗? 如果 serviceNamespace是 hello和 serviceTag是 1.0.0我会结束与 serviceNamespace是 hello-1.0.0？

100753

小开

Update

It is now possible in the 1.11 version of golang, see commit:

\{\{- $serviceNamespace := .Values.serviceNamespace -}}
\{\{- $serviceTag := .Values.serviceTag -}}
\{\{- if $serviceTag}}
\{\{- $serviceNamespace = print .Values.serviceNamespace  "-" .Values.serviceTag -}}
\{\{- end}}

Notice the new = operator in $serviceNamespace = print .Values.serviceNamespace "-" .Values.serviceTag

Older golang versions

You cannot currently (in golang 1.9, but available in 1.11, see update above) reassign template variables because if introduces a new scope. Until this is fixed (see issue and proposed fix), you can work around this by writing a function:

\{\{ define "makeServiceNamespace" }}
\{\{- if .Values.serviceTag }}
\{\{- printf "%s-%s" .Values.serviceNamespace .Values.serviceTag -}}
\{\{- else }}
\{\{- print .Values.serviceNamespace }}
\{\{- end }}
\{\{- end }}

Then use it like so:

serviceNamespace: \{\{ template makeServiceNamespace . }}