MongoDB mongo-go-driver and Change Streams Examples

• 02/25/2019: Replaced with go.mongodb.org/mongo-driver (v1.0.0-rc1)

A MongoDB Change Streams implementation using mongodb-go-driver.

mongo-go-driver Examples

Examples can be found at examples.

• Aggregate
  • $group
  • $redact
  • $filter
  • $lookup
  • $elemMatch
• Change Streams
• CRUD
• RunCommand
• Transactions

Change Streams Demo

Set up a replica set

mkdir -p data/db
rm -rf data/db/*
mongod --port 30097 --dbpath data/db --logpath data/mongod.log --fork --wiredTigerCacheSizeGB .5  --replSet replset
mongo --quiet mongodb://localhost:30097/admin --eval 'rs.initiate()'
mongo --quiet mongodb://localhost:30097/argos?replicaSet=replset --eval 'db.oplogs.insert({"_id": "30097", "scores": [100]})'

Case 1: Watch All Changes

argos "mongodb://localhost:30097/?replicaSet=replset"

Case 2: Watch Changes From a Database

argos "mongodb://localhost:30097/argos?replicaSet=replset"

Case 3: Watch Changes From a Collection

argos --collection oplogs "mongodb://localhost:30097/argos?replicaSet=replset"

Case 4: Watch Changes From a Collection With a Pipeline

argos --collection --pipeline '[{"$match": {"operationType": "update"}}]' \
  "mongodb://localhost:30097/argos?replicaSet=replset"

Stream POC

It would be nice mongo-go-drive can do stream. See POC for an example.

client.Database(db).Collection(collection).Find(filter).Project(project).Sort(sort).Decode(&docs)