I'm trying to provide a condition inside my helm template to check for a valid (or a rather invalid) hostname using regexMatch function.
Here's my line of code that I'm using:
{{- if regexMatch "(?:[0-9]{1,3}\.){3}[0-9]{1,3}$" .Values.hostname }}
The related part in the values file is a simple one:
hostname: 10.10.10.10
However, I'm hitting a syntax error with no real explanation:
Error: parse error at (api-gateway/templates/ingress.yml:1): invalid syntax
When I've tried to use the example from the docs: https://helm.sh/docs/chart_template_guide/function_list/#regexmatch-mustregexmatch
it obviously worked, so I wonder why my code isn't working.
Turns out that I needed to use a double backslash to make it work:
{{- if regexMatch "(?:[0-9]{1,3}\\.){3}[0-9]{1,3}$" .Values.hostname }}
Related
In a shell scrip I want to assigning a variable what to use in a value in a deployment. For the life of me I can not figure out how to get it to work.
My helm deploy script file has the following in order to set the value to use my variable :
--set AuthConfValue=$AUTH_CONF_VALUE
And I have this in the deployment.yaml file in order to use the variable :
- name: KONG_SETTING
value: "{ {{ .Values.AuthConfValue }} }"
If I assign the variable in my shell script like the following :
AUTH_CONF_VALUE="ernie"
It will work and the value in the deployment will show up like so:
value: '{ ernie }'
Now if I try to assign the variable like this:
AUTH_CONF_VALUE="\\\"ernie\\\":\\\"123\\\""
I will then get the error error converting YAML to JSON: yaml: line 118: did not find expected key when the helm deploy runs.
I was hoping that this would give me the following value in the deployment :
value: "{ "ernie":"123" }"
If I hardcode the value into the deployment.yaml with this:
- name: KONG_SETTING
value: "{ \"ernie\": \"123\" }"
and then run the helm deploy it will work and populate the value in the deployment with this -
value: "{ "ernie":"123" }"
Can someone show me if/how I might be able to do this?
The Helm --set option also uses backslash escaping. So in your example, the $AUTH_CONF_VALUE variable in the host shell contains a single backslash before each quote, which is consumed by --set, so .Values.AuthConfValue contains no backslashes at all, and you get invalid YAML.
If you want to keep this as close to the existing form as you can, let's construct a string with no backslashes at all (and hopefully no commas or brackets either, since those also have special meaning to --set)
AUTH_CONF_VALUE='"ernie":"123"'
helm install --set AuthConfValue="$AUTH_CONF_VALUE" .
When Helm expands a template it doesn't know anything about the context where it might be used. In your case, you know
.Values.AuthConfValue is the body of a JSON object
If you surround it in curly braces { ... } then it should be a valid JSON object
You need to turn that into a correctly-escaped YAML string
Helm contains a lightly-documented toJson function that takes an arbitrary object and converts it to JSON; any valid JSON is also valid YAML. So the closest-to-what-you-have approach might look like
- name: KONG_SETTING
value: {{ printf "{%s}" .Values.AuthConfValue | toJson }}
If you're willing to modify your deploy process a little more, you can have less escaping and more certainty. In the sequence above, we have a string that happens to be a JSON object; what if we had an actual object? Imagine settings like
# kong-auth.yaml
authConf:
ernie: "123"
You could provide this file at install time with a helm install -f option. Since valid JSON is valid YAML, again, you could also provide a JSON file here without changing anything.
helm install -f kong-auth.yaml .
Now with this setup .Values.authConf is an object; the only escaping you need to do is standard YAML/JSON escaping (for example quoting "123" so it's a string and not a number). Now we can use toJson twice, once to get the {"ernie":"123"} JSON object string, and a second time to escape that string as a value "{\"ernie\":\"123\"}".
- name: KONG_SETTING
value: {{ .Values.authConf | toJson | toJson }}
Setting this up would require modifying your deployment script, but it would be much safer against quoting and escaping concerns.
I am trying to render a file using the tpl function. I am retrieving the content of the file using Files.Get, which works fine until I use tpl function on it.
My input file is:
apiVersion: autoscaling/v2beta2
My helm template is:
{{- $files := .Files }}
{{- tpl ($files.Get "files/autoscaling.yaml" ) . -}}
I had to use $files because it would throw the error:
at <.Files.Get>: can't evaluate field Files in type interface {}
The output that I see when I run the helm template is
Error: template: subchart-demoapp/templates/sub-deployments.yaml:5:47: executing "subchart-demoapp/templates/sub-deployments.yaml" at <.>: wrong type for value; expected chartutil.Values; got string
helm.go:84: [debug] template: subchart-demoapp/templates/sub-deployments.yaml:5:47: executing "subchart-demoapp/templates/sub-deployments.yaml" at <.>: wrong type for value; expected chartutil.Values; got string
My helm version is:
version.BuildInfo{Version:"v3.2.1", GitCommit:"fe51cd1e31e6a202cba7dead9552a6d418ded79a", GitTreeState:"clean", GoVersion:"go1.13.10"}
Thanks for any help.
Figured it out. tpl function when used in a range block needs the top-level context as the second argument. Ref: Helm Issue
Replaced the . with $ and it works as expected.
While deploying a Kubernetes application, I want to check if a particular PodSecurityPolicy exists, and if it does then skip installing it again.
I came across the helm lookup function, which allows us to check the existing K8 resources.
While I understand how to use this function to get all the resources of same kind, how do I use this function to check if a PodSecurityPolicy named "myPodSecurityPolicy" exists.
I tried something like this:
{{- if ne (lookup "v1" "PodSecurityPolicy" "" "") "myPodSecurityPolicy"}}
<do my stuff>
{{- end }}
But it doesn't look like I can compare it this way, seeing an error -
error calling ne: invalid type for comparison
Any inputs? Thanks in advance.
Please check your API version and PSP name. Lookup is returning a map or nil not a string and that's why you are getting that error. The following is working for me. For negative expression, just add not after if.
{{- if (lookup "policy/v1beta1" "PodSecurityPolicy" "" "example") }}
<found: do your stuff>
{{- end }}
HTH
Using Helm, I was under the impression default would be the fallback if a variable is not defined. However, it doesn't appear Helm can get to values in sub-object hashes:
type: {{ default "NodePort" .Values.fpm.service.type }}
If .Values.fpm.service or service.type is not defined, it should use 9000.
However, attempting to template this throws a nil pointer error:
<.Values.fpm.service.type>: nil pointer evaluating interface {}.type
Is there a way to simply perform this level of variable testing? Or am I subjected to an if/else test?
The intent of this is to optionally define .fpm.service (and [..].type) within your values.yaml file.
(I'm building a Helm Library chart to handle optional definitions by main charts)
According to the official Helm doc (Using Default Function), the syntax is different and you should use it this way:
type: {{ .Values.fpm.service.type | default "NodePort" | quote }}
Doesn't look like there's really a good way to stop Helm from trying to dive into non-existing objects. I moved into a single line if condition, and it worked:
type: {{ if .Values.fpm.service -}} {{ .default "NodePort" .Values.fpm.service.type | quote }} {{- else -}} "NodePort" {{- end }}
This way, I check if fpm.service exists first, before trying .type check. It works, whether .service and .service.type is or is not defined.
I am creating a helm chart in which I want to specify a default for a value using a template function. Specifically I want to either use the override value image.name, or default to the template function chart.name:
{{ .Values.image.name | default include chart.name . }}
But when linting the chart I have the following error:
[ERROR] templates/: render error in "chart/templates/deployment.yaml": template: chart/templates/deployment.yaml:22:81: executing "chart/templates/deployment.yaml" at <include>: wrong number of args for include: want 2 got 0
Is it possible to use an included template function as the default value? Or can I only use literals?
You can. Just enclose your include statement in parentheses:
{{ .Values.image.name | default (include "chart.name" .)}}
Please see using the default function