<p>Why am I getting receiver null used in route? Commenting out the route related to <code>null</code> still produces the same error.</p>
<p>Any idea how to resolve this? Does the config look correct? It did work yesterday but I deleted everything and tried to reinstall and I get this error.</p>
<p><code>failed: provision alertmanager configuration: base config from Secret could not be parsed: undefined receiver \&quot;null\&quot; used in route</code></p>
<p>Also how can I have separate email for each alert? When it works it usually sends a groped alert. Can I just disable route section and have only receivers? Would that send alerts separately? <code>group_by: ['...']</code> still sends by grouping..</p>
<pre><code>  config:
    global:
      resolve_timeout: 5m
    route:
      group_by: ['job']
      group_wait: 30s
      group_interval: 5m
      repeat_interval: 30m
      receiver: 'null'
      routes:
      - match:
          alertname: Watchdog
        receiver: 'null'
    receivers:
    - name: 'null'
    route:
      group_by: ['...']
      receiver: 'email-alert'
    receivers:
    - name: 'email-alert'
      email_configs:
      - to: test@gmail.com
        from: test@gmail.com
        smarthost: postfix.test-internal:25
        require_tls: false
</code></pre>
<p>Here is the log entries:</p>
<pre><code>level=info ts=2020-12-21T03:17:54.675369726Z caller=operator.go:1163 component=prometheusoperator msg=&quot;sync prometheus&quot; key=monitoring/prometheus-kube-prometheus-prometheus
level=error ts=2020-12-21T03:17:54.678077463Z caller=klog.go:96 component=k8s_client_runtime func=ErrorDepth msg=&quot;Sync \&quot;monitoring/prometheus-kube-prometheus-alertmanager\&quot; failed: provision alertmanager configuration: base config from Secret could not be parsed: undefined receiver \&quot;null\&quot; used in route&quot;
level=info ts=2020-12-21T03:17:57.297131904Z caller=operator.go:661 component=alertmanageroperator msg=&quot;sync alertmanager&quot; key=monitoring/prometheus-kube-prometheus-alertmanager
level=info ts=2020-12-21T03:17:57.29721675Z caller=operator.go:1163 component=prometheusoperator msg=&quot;sync prometheus&quot; key=monitoring/prometheus-kube-prometheus-prometheus
level=error ts=2020-12-21T03:17:57.301610335Z caller=klog.go:96 component=k8s_client_runtime func=ErrorDepth msg=&quot;Sync \&quot;monitoring/prometheus-kube-prometheus-alertmanager\&quot; failed: provision alertmanager configuration: base config from Secret could not be parsed: undefined receiver \&quot;null\&quot; used in route&quot;
level=info ts=2020-12-21T03:17:59.906899712Z caller=operator.go:1163 component=prometheusoperator msg=&quot;sync prometheus&quot; key=monitoring/prometheus-kube-prometheus-prometheus
level=info ts=2020-12-21T03:17:59.909936845Z caller=operator.go:661 component=alertmanageroperator msg=&quot;sync alertmanager&quot; key=monitoring/prometheus-kube-prometheus-alertmanager
level=error ts=2020-12-21T03:17:59.915494013Z caller=klog.go:96 component=k8s_client_runtime func=ErrorDepth msg=&quot;Sync \&quot;monitoring/prometheus-kube-prometheus-alertmanager\&quot; failed: provision alertmanager configuration: base config from Secret could not be parsed: undefined receiver \&quot;null\&quot; used in route&quot;
</code></pre>

user630702
<p>In YAML, <code>null</code> and <code>&quot;null&quot;</code> aren't the same thing.</p>
<ul>
<li><code>null</code>: represents NULL value</li>
<li><code>&quot;null&quot;</code>: represents a string equal to <code>&quot;null&quot;</code>.</li>
</ul>
<p>Try removing the qoutes:</p>
<pre class="lang-yaml prettyprint-override"><code>      routes:
      - match:
          alertname: Watchdog
        receiver: null
    receivers:
    - name: null
</code></pre>
