pyrox.dev
buildkite-agent: secrecy improvements: non-store, non-Nix provisioning of secrets
authored by Kosyrev Serge and committed by Domen Kožar 3fa4e1e3 3385c85f
+40
-22
nixos/modules/services/continuous-integration/buildkite-agent.nix
+40
-22
nixos/modules/services/continuous-integration/buildkite-agent.nix
···
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let
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cfg = config.services.buildkite-agent;
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configFile = pkgs.writeText "buildkite-agent.cfg"
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''
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token="${cfg.token}"
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name="${cfg.name}"
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meta-data="${cfg.meta-data}"
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hooks-path="${cfg.package}/share/hooks"
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build-path="${cfg.dataDir}"
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'';
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in
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{
···
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type = types.listOf types.package;
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};
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token = mkOption {
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type = types.str;
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tokenPath = mkOption {
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type = types.path;
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description = ''
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The token from your Buildkite "Agents" page.
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A run-time path to the token file, which is supposed to be provisioned
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outside of Nix store.
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'';
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};
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···
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};
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openssh =
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{ privateKey = mkOption {
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type = types.str;
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{ privateKeyPath = mkOption {
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type = types.path;
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description = ''
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Private agent key.
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+
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A run-time path to the key file, which is supposed to be provisioned
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outside of Nix store.
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'';
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};
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publicKey = mkOption {
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type = types.str;
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publicKeyPath = mkOption {
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type = types.path;
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description = ''
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Public agent key.
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A run-time path to the key file, which is supposed to be provisioned
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outside of Nix store.
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'';
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};
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};
···
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home = cfg.dataDir;
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createHome = true;
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description = "Buildkite agent user";
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extraGroups = [ "keys" ];
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};
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environment.systemPackages = [ cfg.package ];
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systemd.services.buildkite-agent =
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let copy = x: target: perms:
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"cp -f ${x} ${target}; ${pkgs.coreutils}/bin/chmod ${toString perms} ${target}; ";
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in
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{ description = "Buildkite Agent";
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wantedBy = [ "multi-user.target" ];
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after = [ "network.target" ];
···
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HOME = cfg.dataDir;
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NIX_REMOTE = "daemon";
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};
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## NB: maximum care is taken so that secrets (ssh keys and the CI token)
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## don't end up in the Nix store.
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preStart = ''
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${pkgs.coreutils}/bin/mkdir -m 0700 -p ${cfg.dataDir}/.ssh
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${pkgs.coreutils}/bin/mkdir -m 0700 -p ${cfg.dataDir}/.ssh
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${copy (toString cfg.openssh.privateKeyPath) "${cfg.dataDir}/.ssh/id_rsa" 600}
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${copy (toString cfg.openssh.publicKeyPath) "${cfg.dataDir}/.ssh/id_rsa.pub" 600}
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echo "${cfg.openssh.privateKey}" > ${cfg.dataDir}/.ssh/id_rsa
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${pkgs.coreutils}/bin/chmod 600 ${cfg.dataDir}/.ssh/id_rsa
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-
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echo "${cfg.openssh.publicKey}" > ${cfg.dataDir}/.ssh/id_rsa.pub
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${pkgs.coreutils}/bin/chmod 600 ${cfg.dataDir}/.ssh/id_rsa.pub
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'';
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cat > "${cfg.dataDir}/buildkite-agent.cfg" <<EOF
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token="$(cat ${toString cfg.tokenPath})"
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name="${cfg.name}"
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meta-data="${cfg.meta-data}"
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hooks-path="${pkgs.buildkite-agent}/share/hooks"
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build-path="${cfg.dataDir}/builds"
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bootstrap-script="${pkgs.buildkite-agent}/share/bootstrap.sh"
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EOF
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'';
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serviceConfig =
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{ ExecStart = "${pkgs.buildkite-agent}/bin/buildkite-agent start --config ${configFile}";
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{ ExecStart = "${pkgs.buildkite-agent}/bin/buildkite-agent start --config /var/lib/buildkite-agent/buildkite-agent.cfg";
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User = "buildkite-agent";
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RestartSec = 5;
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Restart = "on-failure";
···
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};
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};
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};
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imports = [
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(mkRenamedOptionModule [ "services" "buildkite-agent" "token" ] [ "services" "buildkite-agent" "tokenPath" ])
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(mkRenamedOptionModule [ "services" "buildkite-agent" "openssh" "privateKey" ] [ "services" "buildkite-agent" "openssh" "privateKeyPath" ])
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(mkRenamedOptionModule [ "services" "buildkite-agent" "openssh" "publicKey" ] [ "services" "buildkite-agent" "openssh" "publicKeyPath" ])
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];
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}