Add a node-specific ip echo service to remove dependency on ifconfig.co (#4137)

ci/nits.sh

@@ -18,14 +18,14 @@ declare prints=(
 # Parts of the tree that are expected to be print free
 declare print_free_tree=(
   'core/src'
-  'drone'
-  'metrics'
-  'netutil'
-  'runtime'
-  'sdk'
+  'drone/src'
+  'metrics/src'
+  'netutil/src'
+  'runtime/src'
+  'sdk/src'
 )
 
-if _ git grep "${prints[@]/#/-e }" -- "${print_free_tree[@]}"; then
+if _ git grep --max-depth=0 "${prints[@]/#/-e }" -- "${print_free_tree[@]}"; then
     exit 1
 fi