add geth_extra_data in form of hostname

Signed-off-by: Jakub Sokołowski <jakub@status.im>

defaults/main.yml

@@ -4,6 +4,9 @@ geth_account_addr: ~
 geth_account_pass: ~
 geth_account_json: ~
 
+# Geth miner extra data
+geth_extra_data: '{{ hostname }}'
+
 # Container config
 geth_cont_image: 'ethereum/client-go:v1.8.27'
 geth_cont_name: 'geth'

tasks/container.yml

@@ -43,6 +43,7 @@
       {% if geth_metrics_enabled %}
       --metrics
       {% endif %}
+      --extradata={{ geth_extra_data }}
       --verbosity={{ geth_log_level_id }} 
       --cache={{ geth_cache }}
       --maxpeers={{ geth_max_peers }}