Permission denied (publickey) when connecting to a Lambda GPU Cloud instance

TL;DR

Specify the key file explicitly on the connect command: ssh -i ~/.ssh/lambda_key.pem ubuntu@[instance IP].

The error

Permission denied (publickey) when connecting to a Lambda GPU Cloud instance

Fix

1. Specify the key file explicitly on the connect command: ssh -i ~/.ssh/lambda_key.pem ubuntu@[instance IP]. Expected: you can confirm this matches your situation.

2. Re-run the original operation and confirm the error is gone. Expected: no error, normal output.

When to use

• You hit this exact error.
• The symptom matches: Permission denied (publickey) when connecting to a Lambda GPU Cloud instance.

When NOT to use

• A different error message; the cause here is specific to this error.
• Unrelated issues with a different cause.
• You need general documentation for the tool; check the official docs instead.

Compatibility

Reported per the linked source. Source: https://github.com/piperandrew/textmining_py/blob/HEAD/usingLambdaAI.MD.

Variant phrasings

Permission denied (publickey) when connecting to a Lambda GPU Cloud instance

Why it happens

SSH to a Lambda (lambda.ai) GPU Cloud instance fails with Permission denied (publickey) right after launch, even though an SSH key was added when the instance was created. The default login user on Lambda instances is ubuntu, and the ssh client often picks the wrong local key.

Edge cases

• If your error message differs even slightly, this is probably a different issue; search the exact text.
• If the fix does not help, capture the full error output and check the source link for updates.

Source

https://github.com/piperandrew/textmining_py/blob/HEAD/usingLambdaAI.MD

Source: SSH to a Lambda (lambda.ai) GPU Cloud instance fails with Permission denied (publickey) right after launch, even though an SSH key was added when the instance was created. The default login user on Lambda instances is ubuntu, and the ssh client often picks the wrong local key.

Verified resolution: [troubleshooting notes]: Specify the key file explicitly on the connect command: ssh -i ~/.ssh/lambda_key.pem ubuntu@[instance IP]. If it still fails, confirm the key you passed at instance launch matches the local private key (the public half must be on the instance). Permission denied (publickey) on Lambda almost always means the wrong local key, not a server-side problem.

Source URL: https://github.com/piperandrew/textmining_py/blob/HEAD/usingLambdaAI.MD