Kubernetes: Putting JSON value in YAML file

Question

I am trying to create a secret from a JSON value but I keep getting this error executing "secrets.yaml" at <b64enc>: wrong type for value; expected string; got map[string]interface {} when I do helm install.

secrets.yaml

apiVersion: v1
kind: Secret
metadata:
  name: cloudsql-instance-credentials
  namespace: wp-{{ .Values.name }}
  labels:
    app: wp-{{ .Values.name }}
type: Opaque
data:
  credentials.json: {{ .Values.dbCred | b64enc }}

values.yaml

dbCred: {
  'type': '',
  'project_id': '',
  'private_key_id': '',
  'private_key': '-----BEGIN PRIVATE KEY-----\n\n-----END PRIVATE KEY-----\n',
  'client_email': '',
  'client_id': '',
  'auth_uri': '',
  'token_uri': '',
  'auth_provider_x509_cert_url': '',
  'client_x509_cert_url': ''
}

Try `toJson .Values.dbCred | b64enc`. Or you could even try putting the values in json structure in the values.yaml as yaml and letting helm convert to json for you - https://stackoverflow.com/a/53342487/9705485 — Ryan Dawson, Dec 10 '18 at 11:44

score 2 · Accepted Answer · answered Dec 10 '18 at 11:50

2

You can fix this by changing {{ .Values.dbCred | b64enc }} to {{ toJson .Values.dbCred | b64enc }}

answered Dec 10 '18 at 11:50

Ryan Dawson

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I tried putting that secrets.yaml and values entry into an example chart generated with `helm create` and was able to recreate the error. I then made this change and found I then don't get the error – Ryan Dawson Dec 10 '18 at 11:50
@O’Dane Brissett Bit confused by the question. This example discussed is a secrets.yaml – Ryan Dawson Aug 30 '20 at 12:25
I'm using octopus deploy to set the variable then substitute the values in my helm. However using the example above i get the error `did not find expected key` – O'Dane Brissett Aug 31 '20 at 13:43
@O’Dane Brissett I'd suggest trying it outside of octopus, If that works then you know it's a problem at the octopus level. If it doesn't work then I'd suggest a new question on SO or an issue on the helm repo. – Ryan Dawson Sep 01 '20 at 12:22

score 1 · Answer 2 · answered Dec 10 '18 at 11:52

1

Alternatively, you can keep your credentials.json file inside chart directory, and access file inside your template

data:
  credentials.json: {{ .Files.Get "credentials.json" | b64enc }}

answered Dec 10 '18 at 11:52

edbighead

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So slick! Exactly what I was looking for. – gmaghera Aug 22 '19 at 22:50

score 0 · Answer 3 · answered Dec 10 '18 at 12:30

use double-quote("") before and after dbCred as below

dbCred: "{
  'type': '',
  'project_id': '',
  'private_key_id': '',
  'private_key': '-----BEGIN PRIVATE KEY-----\n\n-----END PRIVATE KEY-----\n',
  'client_email': '',
  'client_id': '',
  'auth_uri': '',
  'token_uri': '',
  'auth_provider_x509_cert_url': '',
  'client_x509_cert_url': ''
}"

Other things look okay.

score 0 · Answer 4 · answered Dec 10 '18 at 12:51

You can do as follow for your configuration:

apiVersion: v1
kind: Secret
metadata:
  name: cloudsql-instance-credentials
  namespace: wp-{{ .Values.name }}
  labels:
    app: wp-{{ .Values.name }}
type: Opaque
data:
  credentials.json: |-
     {{ include (print $.Template.BasePath "/_helper_conf.tpl") . | b64enc }}

Please note that when you are trying to inject configuration into secret ( espacially large ones ) you might need to use |-

you can also use a helper like

{{ include (print $.Template.BasePath "/_helper_conf.tpl") . | b64enc }}

Or even better, in you yaml configuration ( values.yml ) you can just write as follow:

dbCred:
  type: ''
  project_id: ''
  private_key_id: ''
  private_key: '-----BEGIN PRIVATE KEY-----\n\n-----END PRIVATE KEY-----\n'
  client_email: ''
  client_id: ''
  auth_uri: ''
  token_uri: ''
  auth_provider_x509_cert_url: ''
  client_x509_cert_url: ''

to use this sort of configuration you can check the object bellow:

apiVersion: v1
kind: Secret
metadata:
  name: cloudsql-instance-credentials
  namespace: wp-{{ .Values.name }}
  labels:
    app: wp-{{ .Values.name }}
type: Opaque
data:
  credentials.json: |-
     {{ toJson .Values.dbCred | b64enc }}

The use of this configuration is to provide an abstraction of the json provided and put it inside your values.yml

{{ toJson .Values.dbCred | b64enc }}

Note that this might be duplicated if you support multiple environments, so you might prefer to use a helper and some variables inside ( or tpl ) to avoid duplicated code

I hope this helps

Kubernetes: Putting JSON value in YAML file

4 Answers4