[cloud-mongodb-statefulset]: MongoDB binds to localhost by default

[areller]

You have to explicitly specify bind_ip, otherwise mongodb will bind to localhost and won't be able to communicate with other nodes and create a replica set

[stigok]

That sure took a while for me to figure out too. The upstream example files specifies --bind_ip correctly.

When it binds to localhost, you will get seemingly healthy pods while the sidecar goes in an error loop

Error in workloop { MongoError: failed to connect to server [10.244.0.67:27017] on first connect [MongoError: connect ECONNREFUSED 10.244.0.67:27017]
    at Pool.<anonymous> (/opt/cvallance/mongo-k8s-sidecar/node_modules/mongodb-core/lib/topologies/server.js:336:35)
    at Pool.emit (events.js:180:13)
    at Connection.<anonymous> (/opt/cvallance/mongo-k8s-sidecar/node_modules/mongodb-core/lib/connection/pool.js:280:12)
    at Object.onceWrapper (events.js:272:13)
    at Connection.emit (events.js:180:13)
    at Socket.<anonymous> (/opt/cvallance/mongo-k8s-sidecar/node_modules/mongodb-core/lib/connection/connection.js:189:49)
    at Object.onceWrapper (events.js:272:13)
    at Socket.emit (events.js:180:13)
    at emitErrorNT (internal/streams/destroy.js:64:8)
    at process._tickCallback (internal/process/next_tick.js:114:19)
  name: 'MongoError',
  message: 'failed to connect to server [10.244.0.67:27017] on first connect [MongoError: connect ECONNREFUSED 10.244.0.67:27017]' }

[areller]

@stigok In that case the actual code lab (as seen in the attached screenshot) is inconsistent with the upstream example files that you've mentioned because in the code lab itself they don't specify a bind-ip argument so it automatically binds to localhost.