Non-interactive scp

Question

I'm creating a bash script to create new EC2 instances and then upload a file once the instance is created. I'm using scp to upload the file, however, since this is the first time I'm connecting to the instance the script is prompted with "Are you sure you want to continue connecting (yes/no)?" since the authenticity of the host is not known. The script needs to run non-interactively.

Is it possible to avoid the prompt (there doesn't seem to be an obvious command line option). If not is there an alternative method or command I can use to upload the file?

Answer 1

You can set the option StrictHostKeyChecking to no in ~/.ssh/config. See ssh_config(5)

Answer 2

Although maybe not the definitive and safest solution, you could try writing an expect script.