cat command not working as expected using ssh-CodePudding

I am creating a yaml file in GitHub Actions to install softwares on Linux servers created using terraform. Using the pipeline i am able to ssh into the linux servers. In one of the servers i am creating a .ssh directory and an id_rsa file (which contains the private key of the other server) which i intend to use to scp into the other server to copy some files. I have used the echo command to copy the private key to id_rsa file. I want to view the content of id_rsa to make sure the correct private key is copied. I am using the cat command but it does not work. here is my code

ssh chefnode -T
ssh chefnode -t 'sudo apt-get update && sudo apt-get upgrade -y'
ssh chefnode -t 'echo "$INFRA_PRIVATE_KEY" > "/home/'$SSH_NODE_USER'/.ssh/id_rsa"'
ssh chefnode -t 'cat "/home/'$SSH_NODE_USER'/.ssh/id_rsa"'

the commands run but the cat command does not return any output. It does not fail. the pipeline passes but this command does not render any output. I have tried the following combinations as well but nothing works

ssh chefnode -t 'cat /home/"$SSH_NODE_USER"/.ssh/id_rsa'
ssh chefnode -t 'cat /home/$SSH_NODE_USER/.ssh/id_rsa'
ssh chefnode -t cat /home/'$SSH_NODE_USER'/.ssh/id_rsa
ssh chefnode -t cat /home/$SSH_NODE_USER/.ssh/id_rsa

I tried this too

ssh chefnode -t 'echo "$INFRA_PRIVATE_KEY" > "/home/'$SSH_NODE_USER'/.ssh/id_rsa"'
ssh chefnode -t 'cd "/home/'$SSH_NODE_USER'/.ssh";"cat id_rsa"'

says cat command not found. I just want to view the contents of id_rsa file, not sure what i am doing wrong.

CodePudding user response：

ssh chefnode -t 'echo "$INFRA_PRIVATE_KEY" > "/home/'$SSH_NODE_USER'/.ssh/id_rsa"'

Unless $INFRA_PRIVATE_KEY is a variable set by the login environment on chefnode, this is likely to be empty.

I assume you wanted to send a variable set on the local console, but as written this literally sends "$INFRA_PRIVATE_KEY" to the server which probably expands to nothing (i.e. the file is actually empty).

you probably instead want something like:

ssh chefnode -t 'echo "'"$INFRA_PRIVATE_KEY"'" > "/home/'$SSH_NODE_USER'/.ssh/id_rsa"'

which locally expands the variable and then sends it with quoting (assuming there are no quotes embedded in the variable value itself)