Kubernetes Helm, combine two variables with a string in the middle
For concatenation just use printf:
{{- $serviceNamespace := printf "%s-%s" .Values.serviceNamespace .Values.serviceTag -}}
You can simply do it like this , with string ":" in middle
"{{ $values.image.repository }}:{{ $values.image.tag }}"
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 . }}