Log collection stats for certain mongos

playbooks/roles/mongo_3_0/defaults/main.yml

@@ -40,6 +40,7 @@ MONGO_USERS:
     roles: readWrite
 
 MONGO_CLUSTERED: !!null
+MONGO_LOG_COLLECTION_STATS: !!null
 MONGO_BIND_IP: 127.0.0.1
 MONGO_REPL_SET: "rs0"
 

playbooks/roles/mongo_3_0/templates/log-mongo-serverStatus.sh.j2

 #!/usr/bin/env bash
 # Using JSON.stringify forces output of normal JSON, as opposed to Mongo's weird non-compliant extended JSON
 /usr/bin/mongo -u {{ MONGO_ADMIN_USER }} --authenticationDatabase admin -p '{{ MONGO_ADMIN_PASSWORD }}' --quiet <<< 'JSON.stringify(db.serverStatus())'
+
+# This can generate a lot more logging, so only turn it on for environments
+# where you're interested in collection-level statistics
+{% if MONGO_LOG_COLLECTION_STATS %}
+/usr/bin/mongo -u {{ MONGO_ADMIN_USER }} --authenticationDatabase admin -p '{{ MONGO_ADMIN_PASSWORD }}' --quiet <<< '
+rs.slaveOk();
+db.getMongo().getDBNames().forEach(function(database) {
+    if (/^(local|admin)/.test(database))
+        return;
+    thisdb = db.getSiblingDB(database);
+    thisdb.getCollectionNames().forEach(function(collection) {print(JSON.stringify(thisdb[collection].stats()))});
+});
+'
+{% endif %}