helm escape ` in template yaml file

Question

Does anyone know how to espace ` in helm template?

I try to add \ in front doesn't seem to work

original:

{{- if not .Values.istio_cni.chained }}
            k8s.v1.cni.cncf.io/networks: '{{ appendMultusNetwork (index .ObjectMeta.Annotations `k8s.v1.cni.cncf.io/networks`) `istio-cni` }}',
            {{- end }}

Tried:

  {{- if not .Values.istio_cni.chained }}
            k8s.v1.cni.cncf.io/networks: '{{`{{ appendMultusNetwork (index .ObjectMeta.Annotations \`k8s.v1.cni.cncf.io/networks\`) `istio-cni` }}`}}',
            {{- end }}

Error:

Error: parse error at (test/templates/istio-sidecar-injector-istio-system-ConfigMap.yaml:29): unexpected "k8s" in operand

Answer 1

In the Go text/template language backticks delimit "raw string constants"; in standard Go, there is no escaping at all inside raw string literals and they cannot contain backticks.

In your example, it looks like you're trying to emit a Go template block into the output. You can make this work if you use double quotes around the variable names inside the template, and then backticks around the whole thing:

#                                    double quotes around string literal
#                                                           v         v
k8s.v1.cni.cncf.io/networks: '{{`{{ appendMultusNetwork ... "istio-cni" }}`}}'
#                               ^                                         ^
#                                    backticks around whole expression