<p>I often see the following snippet in the helm charts:</p>

<pre><code>  labels:
    app: {{ template "app.name" . }}
    chart: {{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}
</code></pre>

<p>Why is the replacement necessary? Are <code>+</code> signs bad?</p>

<p>As per this (<a href="https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#syntax-and-character-set" rel="nofollow noreferrer">https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#syntax-and-character-set</a>) documentation, labels cannot have plus(+) character in its value. </p>

<pre><code>The name segment is required and must be 63 characters or less, beginning and ending with an alphanumeric character ([a-z0-9A-Z]) with dashes (-), underscores (_), dots (.), and alphanumerics between.
</code></pre>
