Some tool directories have mongo.creds.json files:
root@tools-bastion-03:~# ls -l /data/project/*/mongo.creds.json -r-------- 1 root tools.dawikitool 72 Jun 15 2014 /data/project/dawikitool/mongo.creds.json -r-------- 1 root tools.grep 72 Jun 15 2014 /data/project/grep/mongo.creds.json -r-------- 1 root tools.incolabot 72 Jun 15 2014 /data/project/incolabot/mongo.creds.json -r-------- 1 root tools.isbn-usage 72 Jun 15 2014 /data/project/isbn-usage/mongo.creds.json -r-------- 1 root tools.lijebot 72 Jun 15 2014 /data/project/lijebot/mongo.creds.json -r-------- 1 root tools.merliwbot 72 Jun 15 2014 /data/project/merliwbot/mongo.creds.json -r-------- 1 root tools.missingtopics 72 Jun 15 2014 /data/project/missingtopics/mongo.creds.json -r-------- 1 root tools.owintes 72 Jun 15 2014 /data/project/owintes/mongo.creds.json -r-------- 1 root tools.perfect-venn-diagram-generator 72 Jun 15 2014 /data/project/perfect-venn-diagram-generator/mongo.creds.json -r-------- 1 root tools.robin 72 Jun 15 2014 /data/project/robin/mongo.creds.json -r-------- 1 root tools.suggestbot 72 Jun 15 2014 /data/project/suggestbot/mongo.creds.json -r-------- 1 root tools.timescale 72 Jun 15 2014 /data/project/timescale/mongo.creds.json -r-------- 1 root tools.wd-analysis 72 Jun 15 2014 /data/project/wd-analysis/mongo.creds.json -r-------- 1 root tools.wikilint 72 Jun 15 2014 /data/project/wikilint/mongo.creds.json -r-------- 1 root tools.wm-bot 72 Jun 15 2014 /data/project/wm-bot/mongo.creds.json -r-------- 1 root tools.wmk-dev 72 Jun 15 2014 /data/project/wmk-dev/mongo.creds.json root@tools-bastion-03:~#
I believe they stem from an experiment to set up a MongoDB database server in Toolforge that was ultimately cancelled (cf. 44c570f0224a250e59f079346fa5b5dc18adcffe). If they are indeed obsolete, they should be deleted for housekeeping.