diff --git a/nixos/modules/virtualisation/fetch-instance-ssh-keys.bash b/nixos/modules/virtualisation/fetch-instance-ssh-keys.bash new file mode 100644 index 000000000000..4a8601961115 --- /dev/null +++ b/nixos/modules/virtualisation/fetch-instance-ssh-keys.bash @@ -0,0 +1,36 @@ +#!/usr/bin/env bash + +set -euo pipefail + +WGET() { + wget --retry-connrefused -t 15 --waitretry=10 --header='Metadata-Flavor: Google' "$@" +} + +# When dealing with cryptographic keys, we want to keep things private. +umask 077 +mkdir -p /root/.ssh + +echo "Fetching authorized keys..." +WGET -O /tmp/auth_keys http://metadata.google.internal/computeMetadata/v1/instance/attributes/sshKeys + +# Read keys one by one, split in case Google decided +# to append metadata (it does sometimes) and add to +# authorized_keys if not already present. +touch /root/.ssh/authorized_keys +while IFS='' read -r line || [[ -n "$line" ]]; do + keyLine=$(echo -n "$line" | cut -d ':' -f2) + IFS=' ' read -r -a array <<<"$keyLine" + if [[ ${#array[@]} -ge 3 ]]; then + echo "${array[@]:0:3}" >>/tmp/new_keys + echo "Added ${array[*]:2} to authorized_keys" + fi +done