Merge pull request #110784 from talyz/gce-fetch-ssh-keys

google-compute-config: Reintroduce fetch-ssh-keys
This commit is contained in:
Florian Klink 2021-02-20 22:19:53 +01:00 committed by GitHub
commit d0be6dcd70
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2 changed files with 61 additions and 0 deletions

@ -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 </tmp/auth_keys
mv /tmp/new_keys /root/.ssh/authorized_keys
chmod 600 /root/.ssh/authorized_keys
echo "Fetching host keys..."
WGET -O /tmp/ssh_host_ed25519_key http://metadata.google.internal/computeMetadata/v1/instance/attributes/ssh_host_ed25519_key
WGET -O /tmp/ssh_host_ed25519_key.pub http://metadata.google.internal/computeMetadata/v1/instance/attributes/ssh_host_ed25519_key_pub
mv -f /tmp/ssh_host_ed25519_key* /etc/ssh/
chmod 600 /etc/ssh/ssh_host_ed25519_key
chmod 644 /etc/ssh/ssh_host_ed25519_key.pub

@ -69,6 +69,31 @@ in
# GC has 1460 MTU
networking.interfaces.eth0.mtu = 1460;
# Used by NixOps
systemd.services.fetch-instance-ssh-keys = {
description = "Fetch host keys and authorized_keys for root user";
wantedBy = [ "sshd.service" ];
before = [ "sshd.service" ];
after = [ "network-online.target" ];
wants = [ "network-online.target" ];
path = [ pkgs.wget ];
serviceConfig = {
Type = "oneshot";
ExecStart = pkgs.runCommand "fetch-instance-ssh-keys" { } ''
cp ${./fetch-instance-ssh-keys.bash} $out
chmod +x $out
${pkgs.shfmt}/bin/shfmt -i 4 -d $out
${pkgs.shellcheck}/bin/shellcheck $out
patchShebangs $out
'';
PrivateTmp = true;
StandardError = "journal+console";
StandardOutput = "journal+console";
};
};
systemd.services.google-instance-setup = {
description = "Google Compute Engine Instance Setup";
after = [ "network-online.target" "network.target" "rsyslog.service" ];