tailOpLog Error: should not complete about mongo-es HOT 3 CLOSED

I read the source code and guess the oplog tail operation has issue but not sure how to dig into it.

async tailOpLog(): Promise {
return new Promise((resolve, reject) => {
this.tail()
.bufferWithTimeOrCount(
this.controls.elasticsearchBulkInterval,
this.controls.elasticsearchBulkSize,
)
.subscribe(
oplogs => {
this.queue.push(oplogs)
if (!this.running) {
this.running = true
setImmediate(this._processOplog.bind(this))
}
},
err => {
console.error('tail', this.task.name(), err)
reject(err)
},
() => {
const err = new Error('should not complete')
console.error('tail', this.task.name(), err)
reject(err)
},
)
})
}

from mongo-es.

as instructed,
notice: must use a admin user to access oplog.
not sure what does that mean and how to implement.
I create the user "michael" from admin db and assign right "readWrite" to database "books"

from mongo-es.

@flyinghawker

• mongod should running with --replSet
• user should have read permission of local.oplog.rs

from mongo-es.