what error do you get?

you could try to add this:

mongodb://mongo:*****@mongodb.railway.internal:27017/?directConnection=true

because Railway’s internal networking requires directConnection=true for single MongoDB instances

Did that and hardcoded the uri

I have been posting this issue over a week and I am almost ready to move to another hosting service. To make a long story short, I ended up using a railway hosted mongo db. I had the mongo_url set on the application server. I have also hardcoded the railway mongo url. My app runs locally and connects to mongo atlas so it works fine.

I am getting the error below when I push my code to railway. I am at my Witt’s end. Anybody has any ideas?

MongoDB connection failed: ServerSelectionTimeoutError: mongodb.railway.internal:27017: [Errno -2] Name or service not known (configured timeouts: socketTimeoutMS: 10000.0ms, connectTimeoutMS: 10000.0ms), Timeout: 10.0s, Topology Description: <TopologyDescription id: 69432fa40f15139764a09764, topology_type: Single, servers: [<ServerDescription ('mongodb.railway.internal', 27017) server_type: Unknown, rtt: None, error=AutoReconnect('mongodb.railway.internal:27017: [Errno -2] Name or service not known (configured timeouts: socketTimeoutMS: 10000.0ms, connectTimeoutMS: 10000.0ms)')>]>

use the public URL temporarily to confirm it’s a networking issue. Go to MongoDB service, Settings, Networking, Enable public networking and use that URL instead to test?

Done that. Does not work

Also, is railway support always this ineffective?

hmmm. interesting. not sure about railway’s support had not had any bigger issues yet.

I found this:

Search your code for any MongoClient() or get_mongodb_client() calls that run outside of a function - those are the problem. The internal hostname only resolves when the app is actually running and handling requests, not during startup.​​​​​​​​​​​​​​​​

Example:

# connects immediately at startup - FAILS because internal DNS not available yet

client = get_mongodb_client()

db = client["mydb"]

possible fix:

_client = None

def get_mongodb_client():

global _client

if _client is not None:

return _client

uri = os.getenv("MONGO_URL")

if not uri:

raise ValueError("MONGO_URL environment variable is not set")

_client = MongoClient(uri, tls=False)

_client.admin.command("ping")

print("Mongo OK")

return _client

def get_db():

return get_mongodb_client()["mydb"]

# Then in routes - only connects when request comes in:

@app.get("/whatever")

def some_endpoint():

db = get_db()

return db.users.find_one()

Thank you for the response. The key here is that I run the code on my machine with mongo atlas connection and it works fine. The only thing I change is the connection string to railway Mongo and push it to railway and then the connection fail. The only difference is the mongo db url.

Thats why I am not sure why my code from my container can not see the Mongo on the railway mongo.

That is why I am bringing up railways support as being useless. I am not sure how to troubleshoot this on their side.

yeah sounds like a railway network issue if it works with Atlas. hope they will answer your. Keep it up!

can you try connecting via SSH to the container and try to connect to the db with the cli?

Hi,

Thank you for the response. I have disabled TLS in the connection string and still getting the same error. Also, I am too dim to figure out how to SSH connect to my container. Documents I can not find.

To connect via SSH you can just left click on the service, and copy the ssh connection string

Also looking at old threads:

• can you try adding ENABLEALPINEPRIVATE_NETWORKING=true

• can you try adding a 3sec delay in the app start script?
  
  these suggestions comes from this thread:
  https://station.railway.com/questions/unstable-connection-to-mongo-db-via-priva-dc314212

I think you should add an exponential backoff strategy for connecting to the Mongo service. High chance your service tries to connect to it before even the Mongo service is ready.