rewrite_tag plugin hostname command fix to work with OL8 Image on OCR

Author: santhoshkvuda

logan/helm-chart/templates/configmap-logs.yaml

@@ -262,6 +262,7 @@ data:
     # Match block to filter kubelet logs from syslogs
     <match oci.oke.syslog.messages.**>
        @type rewrite_tag_filter
+       hostname_command {{ ((.Values.fluentd).rewriteTagPlugin).hostname_command | default "cat /etc/hostname" }}
        <rule>
        key message
        pattern /kubelet:/

logan/helm-chart/values.yaml

@@ -153,6 +153,11 @@ fluentd:
       # Specifies the encoding of logs. By default, in_tail emits string value as ASCII-8BIT encoding. If encoding is specified, in_tail changes string to given encoding.
       # When encoding is set at this level, it gets applied to all the logs being collected. Instead, it can also be set at individual logs under sections like kubernetesSystem, genericContainerLogs, customLogs etc.
       # encoding: 
+   
+   # Configuration for rewrite_tag plugin
+   rewriteTagPlugin:
+      hostname_command: "cat /etc/hostname" 
+   
    # Configuration for Kubernetes System specific logs like Kube Flannel, Kube Proxy etc.
    kubernetesSystem:
       # Setting the following properties will override the default/generic configuration and applies to all Kubernetes system logs