This requires adding the following to hydra.conf:
binary_cache_key_name = <key-name> binary_cache_private_key_file = <path-to-private-key>
e.g.
binary_cache_key_name = hydra.nixos.org-1 binary_cache_private_key_file = /home/hydra/cache-key.sec
AJVEJENFDMRMPLDWK5OCUIKLS7APCCXDVID5SQMVLY3CIJMYPW3QC }# Optionally, sign the NAR info file we just created.my $privateKeyFile = $c->config->{binary_cache_private_key_file};my $keyName = $c->config->{binary_cache_key_name};if (defined $privateKeyFile && defined $keyName) {my $sig = signString($privateKeyFile, $info);$info .= "Signature: 1;$keyName;$sig\n";