cargo install --git https://github.com/aquarhead/tmp-ssh-key.git

This small tool basically:

• Read private key from stdin
• Write to a temp file
• Change permission on it so ssh is okay to use the key (600)
• Output temp file name to stdout

This could be useful when key retriving can be automated/scripted, in a trusted environment. Example:

alias issh='ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null'
issh user@ip -i $(echo "some key" | tmp-ssh-key)

NOTE: this example explicitly chose to not verify server fingerprint, for example if these are virtual machines then their IPs can be rotated. It's not safe on public network.