Can't authenticate with mongoDB from docker-compose service - node.js

Question

What I'm trying to do
I'm trying to set up a docker-compose definition, where I have a mongoDB container, and a nodeJS container that connects to it.
version: "3.9"
services:
events-db:
image: mongo
volumes:
- db-volume:/data/db
environment:
MONGO_INITDB_ROOT_USERNAME: $SANDBOX_DB_USER
MONGO_INITDB_ROOT_PASSWORD: $SANDBOX_DB_PASS
MONGO_INITDB_DATABASE: sandboxdb
app:
image: node:15.12.0
user: node
working_dir: /home/node/app
volumes:
- ./:/home/node/app:ro
environment:
MDB_CONNECTION: mongodb://$SANDBOX_DB_USER:$SANDBOX_DB_PASS#events-db:27017/sandboxdb
command: node myapp
depends_on:
- events-db
volumes:
db-volume:
Along with a .env file that declares the credentials (planning to use proper env variables when I deploy this to a production environment):
SANDBOX_DB_USER=myuser
SANDBOX_DB_PASS=myp4ss
Finally, my nodejs script, myapp.js is simply trying to connect, grab a reference to a collection, and insert a document:
require('dotenv').config()
const { MongoClient } = require('mongodb')
async function main () {
console.log('Connecting')
const client = new MongoClient(process.env.MDB_CONNECTION, {
connectTimeoutMS: 10000,
useUnifiedTopology: true,
})
await client.connect()
const db = client.db()
const events = db.collection('events')
console.log('Inserting an event')
await events.insertOne({
type: 'foo',
timestamp: new Date(),
})
console.log('Done.')
process.exit(0)
}
if (require.main === module) {
main()
}
Result
When I run docker-compose config I see the following output, so I would expect it to work:
$ docker-compose config
services:
app:
command: node myapp
depends_on:
events-db:
condition: service_started
environment:
MDB_CONNECTION: mongodb://myuser:myp4ss#events-db:27017/sandboxdb
image: node:15.12.0
user: node
volumes:
- C:\workspace\dcsandbox:/home/node/app:ro
working_dir: /home/node/app
events-db:
environment:
MONGO_INITDB_DATABASE: sandboxdb
MONGO_INITDB_ROOT_PASSWORD: myp4ss
MONGO_INITDB_ROOT_USERNAME: myuser
image: mongo
volumes:
- db-volume:/data/db:rw
version: '3.9'
volumes:
db-volume: {}
However, when I run docker-compose up I see that my node container is unable to connect to the mongoDB to insert an event:
events-db_1 | {"t":{"$date":"2021-04-07T13:57:36.793+00:00"},"s":"I", "c":"NETWORK", "id":23016, "ctx":"listener","msg":"Waiting for connections","attr":{"port":27017,"ssl":"off"}}
app_1 | Connecting
events-db_1 | {"t":{"$date":"2021-04-07T13:57:38.811+00:00"},"s":"I", "c":"NETWORK", "id":22943, "ctx":"listener","msg":"Connection accepted","attr":{"remote":"172.27.0.3:34164","connectionId":1,"connectionCount":1}}
events-db_1 | {"t":{"$date":"2021-04-07T13:57:38.816+00:00"},"s":"I", "c":"NETWORK", "id":51800, "ctx":"conn1","msg":"client metadata","attr":{"remote":"172.27.0.3:34164","client":"conn1","doc":{"driver":{"name":"nodejs","version":"3.6.6"},"os":{"type":"Linux","name":"linux","architecture":"x64","version":"4.19.128-microsoft-standard"},"platform":"'Node.js v15.12.0, LE (unified)"}}}
events-db_1 | {"t":{"$date":"2021-04-07T13:57:38.820+00:00"},"s":"I", "c":"NETWORK", "id":22943, "ctx":"listener","msg":"Connection accepted","attr":{"remote":"172.27.0.3:34166","connectionId":2,"connectionCount":2}}
events-db_1 | {"t":{"$date":"2021-04-07T13:57:38.822+00:00"},"s":"I", "c":"NETWORK", "id":51800, "ctx":"conn2","msg":"client metadata","attr":{"remote":"172.27.0.3:34166","client":"conn2","doc":{"driver":{"name":"nodejs","version":"3.6.6"},"os":{"type":"Linux","name":"linux","architecture":"x64","version":"4.19.128-microsoft-standard"},"platform":"'Node.js v15.12.0, LE (unified)"}}}
events-db_1 | {"t":{"$date":"2021-04-07T13:57:38.822+00:00"},"s":"I", "c":"ACCESS", "id":20251, "ctx":"conn2","msg":"Supported SASL mechanisms requested for unknown user","attr":{"user":"myuser#sandboxdb"}}
events-db_1 | {"t":{"$date":"2021-04-07T13:57:38.823+00:00"},"s":"I", "c":"ACCESS", "id":20249, "ctx":"conn2","msg":"Authentication failed","attr":{"mechanism":"SCRAM-SHA-256","principalName":"myuser","authenticationDatabase":"sandboxdb","client":"172.27.0.3:34166","result":"UserNotFound: Could not find user \"myuser\" for db \"sandboxdb\""}}
events-db_1 | {"t":{"$date":"2021-04-07T13:57:38.824+00:00"},"s":"I", "c":"ACCESS", "id":20249, "ctx":"conn2","msg":"Authentication failed","attr":{"mechanism":"SCRAM-SHA-1","principalName":"myuser","authenticationDatabase":"sandboxdb","client":"172.27.0.3:34166","result":"UserNotFound: Could not find user \"myuser\" for db \"sandboxdb\""}}
events-db_1 | {"t":{"$date":"2021-04-07T13:57:38.826+00:00"},"s":"I", "c":"NETWORK", "id":22944, "ctx":"conn1","msg":"Connection ended","attr":{"remote":"172.27.0.3:34164","connectionId":1,"connectionCount":1}}
app_1 | /home/node/app/node_modules/mongodb/lib/cmap/connection.js:268
app_1 | callback(new MongoError(document));
app_1 | ^
app_1 |
app_1 | MongoError: Authentication failed.
app_1 | at MessageStream.messageHandler (/home/node/app/node_modules/mongodb/lib/cmap/connection.js:268:20)
app_1 | at MessageStream.emit (node:events:369:20)
app_1 | at processIncomingData (/home/node/app/node_modules/mongodb/lib/cmap/message_stream.js:144:12)
app_1 | at MessageStream._write (/home/node/app/node_modules/mongodb/lib/cmap/message_stream.js:42:5)
app_1 | at writeOrBuffer (node:internal/streams/writable:395:12)
app_1 | at MessageStream.Writable.write (node:internal/streams/writable:340:10)
app_1 | at Socket.ondata (node:internal/streams/readable:750:22)
app_1 | at Socket.emit (node:events:369:20)
app_1 | at addChunk (node:internal/streams/readable:313:12)
app_1 | at readableAddChunk (node:internal/streams/readable:288:9) {
app_1 | ok: 0,
app_1 | code: 18,
app_1 | codeName: 'AuthenticationFailed'
app_1 | }
events-db_1 | {"t":{"$date":"2021-04-07T13:57:38.832+00:00"},"s":"I", "c":"NETWORK", "id":22944, "ctx":"conn2","msg":"Connection ended","attr":{"remote":"172.27.0.3:34166","connectionId":2,"connectionCount":0}}
dcsandbox_app_1 exited with code 1
I've put the full output at https://pastebin.com/uNyJ6tiy
and the example code at this repo: https://github.com/akatechis/example-docker-compose-mongo-node-auth

Answer 1

After some more digging, I managed to figure it out. The issue is that the MONGO_INITDB_ROOT_USERNAME and MONGO_INITDB_ROOT_PASSWORD variables simply set the root user's credentials, and the MONGO_INITDB_DATABASE simply sets the initial database for scripts in /docker-entrypoint-initdb.d.
By default, the root user is added to the admin database, so by removing the /sandboxdb part of the connection string, I was able to have my node app authenticate against the admin DB as the root user.
While this doesn't quite accomplish what I wanted initially (to create a separate, non-root user for my database, and use that to authenticate), I think this puts me on the right path to using an init script to set up the user accounts I want to have.