title: Secret is not decoding properly using Kubernetes Secrets
body: <p>I am using Kubernetes to deploy my grafana dashboard and I am trying to  use Kubernetes Secrets  for saving grafana admin-password .. Here is my yaml file for secret</p>
  
  <pre><code>    apiVersion: v1
      kind: Secret
      metadata:
        name: $APP_INSTANCE_NAME-grafana
        labels:
          app.kubernetes.io/name: $APP_INSTANCE_NAME
          app.kubernetes.io/component: grafana
      type: Opaque
      data:
        # By default, admin-user is set to `admin`
        admin-user: YWRtaW4=
        admin-password: "$GRAFANA_GENERATED_PASSWORD"
  </code></pre>
  
  <p>value for GRAFANA_GENERATED_PASSWORD is base64 encoded and exported like</p>
  
  <pre><code>export GRAFANA_GENERATED_PASSWORD="$(echo -n $PASSWORD | base64)"
  </code></pre>
  
  <p>where PASSWORD is a variable which i exported on my machine like 
     <code>export PASSWORD=qwerty123</code></p>
  
  <p>I am trying to pass  the value of GRAFANA_GENERATED_PASSWORD to the yaml file for secret like</p>
  
  <pre><code>envsubst '$GRAFANA_GENERATED_PASSWORD'  &gt; "grafana_secret.yaml"
  </code></pre>
  
  <p>The yaml file after passing the base64 encoded value looks like </p>
  
  <pre><code>apiVersion: v1
  kind: Secret
  metadata:
    name: kafka-monitor-grafana
    labels:
      app.kubernetes.io/name: kafka-monitor
      app.kubernetes.io/component: grafana
  type: Opaque
  data:
    # By default, admin-user is set to `admin`
    admin-user: YWRtaW4=
    admin-password: "cXdlcnR5MTIz"
  </code></pre>
  
  <p>After deploying all my objects i couldn't login to my dashboard using password qwerty123 which is encoded properly .. </p>
  
  <p>But when i try to encode my password like 
  <code>export GRAFANA_GENERATED_PASSWORD="$(echo -n 'qwerty123' | base64)</code>"</p>
  
  <p>It is working properly and i can login to my dashboard using the password qwerty123 ..
  Looks like the problem occur when i encode  my password using  a variable  ...
  But i  have encode my password using a variable </p>