When deploying Neo4j using Neo4j's Helm Charts and the container image is hosted in a private container registry protected by a username and password, the following error may be encountered:

Error: UPGRADE FAILED: YAML parse error on templates/neo4j-imagePullSecret.yaml:
error converting YAML to JSON: yaml: line 7: did not find expected key 

Cause

The error is likely caused by the improper usage of capital letters in the yaml sequence for imagePullSecrets, specifically the name entity of imageCredentials. For example, given the following snippet from a values.yml file:

image:
  imagePullPolicy: IfNotPresent
  customImage: custom_neo4j_image:v1

  #imagePullSecrets list
  imagePullSecrets:
    - "mySecret"

  imageCredentials:
    - registry: "custom.io/v1/""
      username: "docker-service-account"
      password: "DOCKER_PASSWD"
      email: "em@ID"
      name: "mySecret"

The helm chart will attempt to create a secret from the imageCredentials sequence with a name of mySecret. This will error because the name has uppercase letters, so it does not conform to Kubernetes Secret naming constraints which can be found on the following link:

https://kubernetes.io/docs/concepts/configuration/secret/#restriction-names-data

More specifically, the name of a secret object must be a valid DNS subdomain name, whose rules are listed here:

https://kubernetes.io/docs/concepts/overview/working-with-objects/names/#dns-subdomain-names

Among those restrictions, uppercase alphanumeric characters are not allowed. It may also be possible for this error to occur if other restrictions for the name are violated, but the presence of uppercase letters will tend to be the most common reason.

Solution

Specify a valid name for the Kubernetes Secret as per the Kubernetes Secret naming constraints. 

In the above example, to fix this issue, change the secret name from mySecret to mysecret.