fly ssh console -C failing with a piped command

Trying to run a piped command:

fly ssh console -C "cat /var/log/nginx/access.log | wc -l"

and it fails with

cat: invalid option -- 'l'
Try 'cat --help' for more information.
Error: ssh shell: Process exited with status 1

I know I can simplify the command in this case to something like this and avoid the pipe:

fly ssh console -C "wc -l /var/log/nginx/access.log"

But my bigger question is whether there’s a problem using piped commands in -C command strings.

Thanks for any help!

Hi @eyepulp, the command that you specify with -C is not run through a shell, which would interpret the pipe. In this case, you’re seeing the SSH server in your app running cat with the literal arguments /var/log/nginx/access.log, |, wc, and -l.

If your app image does contain a shell, then you can invoke it explicitly. E.g., if you have a standard /bin/sh:

fly ssh console -C 'sh -c "cat /var/log/nginx/access.log | wc -l"'

(It’s certainly not pretty! However, some minimal app images might not contain a shell, so this behavior allows fly ssh console -C to work with them too.)

1 Like

That worked – Thanks!

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