diff options
Diffstat (limited to 'nixos/modules/services/continuous-integration/github-runner/service.nix')
-rw-r--r-- | nixos/modules/services/continuous-integration/github-runner/service.nix | 513 |
1 files changed, 262 insertions, 251 deletions
diff --git a/nixos/modules/services/continuous-integration/github-runner/service.nix b/nixos/modules/services/continuous-integration/github-runner/service.nix index 8895f4827bb1..cdf86ca8bfce 100644 --- a/nixos/modules/services/continuous-integration/github-runner/service.nix +++ b/nixos/modules/services/continuous-integration/github-runner/service.nix @@ -1,279 +1,290 @@ { config , lib , pkgs - -, cfg ? config.services.github-runner -, svcName - -, systemdDir ? "${svcName}/${cfg.name}" - # %t: Runtime directory root (usually /run); see systemd.unit(5) -, runtimeDir ? "%t/${systemdDir}" - # %S: State directory root (usually /var/lib); see systemd.unit(5) -, stateDir ? "%S/${systemdDir}" - # %L: Log directory root (usually /var/log); see systemd.unit(5) -, logsDir ? "%L/${systemdDir}" - # Name of file stored in service state directory -, currentConfigTokenFilename ? ".current-token" - , ... }: with lib; - -let - workDir = if cfg.workDir == null then runtimeDir else cfg.workDir; - # Support old github-runner versions which don't have the `nodeRuntimes` arg yet. - package = cfg.package.override (old: optionalAttrs (hasAttr "nodeRuntimes" old) { inherit (cfg) nodeRuntimes; }); -in { - description = "GitHub Actions runner"; + config.assertions = flatten ( + flip mapAttrsToList config.services.github-runners (name: cfg: map (mkIf cfg.enable) [ + { + assertion = !cfg.noDefaultLabels || (cfg.extraLabels != [ ]); + message = "`services.github-runners.${name}`: The `extraLabels` option is mandatory if `noDefaultLabels` is set"; + } + ]) + ); - wantedBy = [ "multi-user.target" ]; - wants = [ "network-online.target" ]; - after = [ "network.target" "network-online.target" ]; + config.systemd.services = flip mapAttrs' config.services.github-runners (name: cfg: + let + svcName = "github-runner-${name}"; + systemdDir = "github-runner/${name}"; - environment = { - HOME = workDir; - RUNNER_ROOT = stateDir; - } // cfg.extraEnvironment; + # %t: Runtime directory root (usually /run); see systemd.unit(5) + runtimeDir = "%t/${systemdDir}"; + # %S: State directory root (usually /var/lib); see systemd.unit(5) + stateDir = "%S/${systemdDir}"; + # %L: Log directory root (usually /var/log); see systemd.unit(5) + logsDir = "%L/${systemdDir}"; + # Name of file stored in service state directory + currentConfigTokenFilename = ".current-token"; - path = (with pkgs; [ - bash - coreutils - git - gnutar - gzip - ]) ++ [ - config.nix.package - ] ++ cfg.extraPackages; + workDir = if cfg.workDir == null then runtimeDir else cfg.workDir; + # Support old github-runner versions which don't have the `nodeRuntimes` arg yet. + package = cfg.package.override (old: optionalAttrs (hasAttr "nodeRuntimes" old) { inherit (cfg) nodeRuntimes; }); + in + nameValuePair svcName { + description = "GitHub Actions runner"; - serviceConfig = mkMerge [ - { - ExecStart = "${package}/bin/Runner.Listener run --startuptype service"; + wantedBy = [ "multi-user.target" ]; + wants = [ "network-online.target" ]; + after = [ "network.target" "network-online.target" ]; - # Does the following, sequentially: - # - If the module configuration or the token has changed, purge the state directory, - # and create the current and the new token file with the contents of the configured - # token. While both files have the same content, only the later is accessible by - # the service user. - # - Configure the runner using the new token file. When finished, delete it. - # - Set up the directory structure by creating the necessary symlinks. - ExecStartPre = - let - # Wrapper script which expects the full path of the state, working and logs - # directory as arguments. Overrides the respective systemd variables to provide - # unambiguous directory names. This becomes relevant, for example, if the - # caller overrides any of the StateDirectory=, RuntimeDirectory= or LogDirectory= - # to contain more than one directory. This causes systemd to set the respective - # environment variables with the path of all of the given directories, separated - # by a colon. - writeScript = name: lines: pkgs.writeShellScript "${svcName}-${name}.sh" '' - set -euo pipefail + environment = { + HOME = workDir; + RUNNER_ROOT = stateDir; + } // cfg.extraEnvironment; - STATE_DIRECTORY="$1" - WORK_DIRECTORY="$2" - LOGS_DIRECTORY="$3" + path = (with pkgs; [ + bash + coreutils + git + gnutar + gzip + ]) ++ [ + config.nix.package + ] ++ cfg.extraPackages; - ${lines} - ''; - runnerRegistrationConfig = getAttrs [ - "ephemeral" - "extraLabels" - "name" - "noDefaultLabels" - "runnerGroup" - "tokenFile" - "url" - "workDir" - ] cfg; - newConfigPath = builtins.toFile "${svcName}-config.json" (builtins.toJSON runnerRegistrationConfig); - currentConfigPath = "$STATE_DIRECTORY/.nixos-current-config.json"; - newConfigTokenPath = "$STATE_DIRECTORY/.new-token"; - currentConfigTokenPath = "$STATE_DIRECTORY/${currentConfigTokenFilename}"; + serviceConfig = mkMerge [ + { + ExecStart = "${package}/bin/Runner.Listener run --startuptype service"; - runnerCredFiles = [ - ".credentials" - ".credentials_rsaparams" - ".runner" - ]; - unconfigureRunner = writeScript "unconfigure" '' - copy_tokens() { - # Copy the configured token file to the state dir and allow the service user to read the file - install --mode=666 ${escapeShellArg cfg.tokenFile} "${newConfigTokenPath}" - # Also copy current file to allow for a diff on the next start - install --mode=600 ${escapeShellArg cfg.tokenFile} "${currentConfigTokenPath}" - } - clean_state() { - find "$STATE_DIRECTORY/" -mindepth 1 -delete - copy_tokens - } - diff_config() { - changed=0 - # Check for module config changes - [[ -f "${currentConfigPath}" ]] \ - && ${pkgs.diffutils}/bin/diff -q '${newConfigPath}' "${currentConfigPath}" >/dev/null 2>&1 \ - || changed=1 - # Also check the content of the token file - [[ -f "${currentConfigTokenPath}" ]] \ - && ${pkgs.diffutils}/bin/diff -q "${currentConfigTokenPath}" ${escapeShellArg cfg.tokenFile} >/dev/null 2>&1 \ - || changed=1 - # If the config has changed, remove old state and copy tokens - if [[ "$changed" -eq 1 ]]; then - echo "Config has changed, removing old runner state." - echo "The old runner will still appear in the GitHub Actions UI." \ - "You have to remove it manually." - clean_state - fi - } - if [[ "${optionalString cfg.ephemeral "1"}" ]]; then - # In ephemeral mode, we always want to start with a clean state - clean_state - elif [[ "$(ls -A "$STATE_DIRECTORY")" ]]; then - # There are state files from a previous run; diff them to decide if we need a new registration - diff_config - else - # The state directory is entirely empty which indicates a first start - copy_tokens - fi - # Always clean workDir - find -H "$WORK_DIRECTORY" -mindepth 1 -delete - ''; - configureRunner = writeScript "configure" '' - if [[ -e "${newConfigTokenPath}" ]]; then - echo "Configuring GitHub Actions Runner" - args=( - --unattended - --disableupdate - --work "$WORK_DIRECTORY" - --url ${escapeShellArg cfg.url} - --labels ${escapeShellArg (concatStringsSep "," cfg.extraLabels)} - --name ${escapeShellArg cfg.name} - ${optionalString cfg.replace "--replace"} - ${optionalString (cfg.runnerGroup != null) "--runnergroup ${escapeShellArg cfg.runnerGroup}"} - ${optionalString cfg.ephemeral "--ephemeral"} - ${optionalString cfg.noDefaultLabels "--no-default-labels"} - ) - # If the token file contains a PAT (i.e., it starts with "ghp_" or "github_pat_"), we have to use the --pat option, - # if it is not a PAT, we assume it contains a registration token and use the --token option - token=$(<"${newConfigTokenPath}") - if [[ "$token" =~ ^ghp_* ]] || [[ "$token" =~ ^github_pat_* ]]; then - args+=(--pat "$token") - else - args+=(--token "$token") - fi - ${package}/bin/Runner.Listener configure "''${args[@]}" - # Move the automatically created _diag dir to the logs dir - mkdir -p "$STATE_DIRECTORY/_diag" - cp -r "$STATE_DIRECTORY/_diag/." "$LOGS_DIRECTORY/" - rm -rf "$STATE_DIRECTORY/_diag/" - # Cleanup token from config - rm "${newConfigTokenPath}" - # Symlink to new config - ln -s '${newConfigPath}' "${currentConfigPath}" - fi - ''; - setupWorkDir = writeScript "setup-work-dirs" '' - # Link _diag dir - ln -s "$LOGS_DIRECTORY" "$WORK_DIRECTORY/_diag" + # Does the following, sequentially: + # - If the module configuration or the token has changed, purge the state directory, + # and create the current and the new token file with the contents of the configured + # token. While both files have the same content, only the later is accessible by + # the service user. + # - Configure the runner using the new token file. When finished, delete it. + # - Set up the directory structure by creating the necessary symlinks. + ExecStartPre = + let + # Wrapper script which expects the full path of the state, working and logs + # directory as arguments. Overrides the respective systemd variables to provide + # unambiguous directory names. This becomes relevant, for example, if the + # caller overrides any of the StateDirectory=, RuntimeDirectory= or LogDirectory= + # to contain more than one directory. This causes systemd to set the respective + # environment variables with the path of all of the given directories, separated + # by a colon. + writeScript = name: lines: pkgs.writeShellScript "${svcName}-${name}.sh" '' + set -euo pipefail - # Link the runner credentials to the work dir - ln -s "$STATE_DIRECTORY"/{${lib.concatStringsSep "," runnerCredFiles}} "$WORK_DIRECTORY/" - ''; - in - map (x: "${x} ${escapeShellArgs [ stateDir workDir logsDir ]}") [ - "+${unconfigureRunner}" # runs as root - configureRunner - setupWorkDir - ]; + STATE_DIRECTORY="$1" + WORK_DIRECTORY="$2" + LOGS_DIRECTORY="$3" - # If running in ephemeral mode, restart the service on-exit (i.e., successful de-registration of the runner) - # to trigger a fresh registration. - Restart = if cfg.ephemeral then "on-success" else "no"; - # If the runner exits with `ReturnCode.RetryableError = 2`, always restart the service: - # https://github.com/actions/runner/blob/40ed7f8/src/Runner.Common/Constants.cs#L146 - RestartForceExitStatus = [ 2 ]; + ${lines} + ''; + runnerRegistrationConfig = getAttrs [ + "ephemeral" + "extraLabels" + "name" + "noDefaultLabels" + "runnerGroup" + "tokenFile" + "url" + "workDir" + ] + cfg; + newConfigPath = builtins.toFile "${svcName}-config.json" (builtins.toJSON runnerRegistrationConfig); + currentConfigPath = "$STATE_DIRECTORY/.nixos-current-config.json"; + newConfigTokenPath = "$STATE_DIRECTORY/.new-token"; + currentConfigTokenPath = "$STATE_DIRECTORY/${currentConfigTokenFilename}"; - # Contains _diag - LogsDirectory = [ systemdDir ]; - # Default RUNNER_ROOT which contains ephemeral Runner data - RuntimeDirectory = [ systemdDir ]; - # Home of persistent runner data, e.g., credentials - StateDirectory = [ systemdDir ]; - StateDirectoryMode = "0700"; - WorkingDirectory = workDir; + runnerCredFiles = [ + ".credentials" + ".credentials_rsaparams" + ".runner" + ]; + unconfigureRunner = writeScript "unconfigure" '' + copy_tokens() { + # Copy the configured token file to the state dir and allow the service user to read the file + install --mode=666 ${escapeShellArg cfg.tokenFile} "${newConfigTokenPath}" + # Also copy current file to allow for a diff on the next start + install --mode=600 ${escapeShellArg cfg.tokenFile} "${currentConfigTokenPath}" + } + clean_state() { + find "$STATE_DIRECTORY/" -mindepth 1 -delete + copy_tokens + } + diff_config() { + changed=0 + # Check for module config changes + [[ -f "${currentConfigPath}" ]] \ + && ${pkgs.diffutils}/bin/diff -q '${newConfigPath}' "${currentConfigPath}" >/dev/null 2>&1 \ + || changed=1 + # Also check the content of the token file + [[ -f "${currentConfigTokenPath}" ]] \ + && ${pkgs.diffutils}/bin/diff -q "${currentConfigTokenPath}" ${escapeShellArg cfg.tokenFile} >/dev/null 2>&1 \ + || changed=1 + # If the config has changed, remove old state and copy tokens + if [[ "$changed" -eq 1 ]]; then + echo "Config has changed, removing old runner state." + echo "The old runner will still appear in the GitHub Actions UI." \ + "You have to remove it manually." + clean_state + fi + } + if [[ "${optionalString cfg.ephemeral "1"}" ]]; then + # In ephemeral mode, we always want to start with a clean state + clean_state + elif [[ "$(ls -A "$STATE_DIRECTORY")" ]]; then + # There are state files from a previous run; diff them to decide if we need a new registration + diff_config + else + # The state directory is entirely empty which indicates a first start + copy_tokens + fi + # Always clean workDir + find -H "$WORK_DIRECTORY" -mindepth 1 -delete + ''; + configureRunner = writeScript "configure" '' + if [[ -e "${newConfigTokenPath}" ]]; then + echo "Configuring GitHub Actions Runner" + args=( + --unattended + --disableupdate + --work "$WORK_DIRECTORY" + --url ${escapeShellArg cfg.url} + --labels ${escapeShellArg (concatStringsSep "," cfg.extraLabels)} + ${optionalString (cfg.name != null ) "--name ${escapeShellArg cfg.name}"} + ${optionalString cfg.replace "--replace"} + ${optionalString (cfg.runnerGroup != null) "--runnergroup ${escapeShellArg cfg.runnerGroup}"} + ${optionalString cfg.ephemeral "--ephemeral"} + ${optionalString cfg.noDefaultLabels "--no-default-labels"} + ) + # If the token file contains a PAT (i.e., it starts with "ghp_" or "github_pat_"), we have to use the --pat option, + # if it is not a PAT, we assume it contains a registration token and use the --token option + token=$(<"${newConfigTokenPath}") + if [[ "$token" =~ ^ghp_* ]] || [[ "$token" =~ ^github_pat_* ]]; then + args+=(--pat "$token") + else + args+=(--token "$token") + fi + ${package}/bin/Runner.Listener configure "''${args[@]}" + # Move the automatically created _diag dir to the logs dir + mkdir -p "$STATE_DIRECTORY/_diag" + cp -r "$STATE_DIRECTORY/_diag/." "$LOGS_DIRECTORY/" + rm -rf "$STATE_DIRECTORY/_diag/" + # Cleanup token from config + rm "${newConfigTokenPath}" + # Symlink to new config + ln -s '${newConfigPath}' "${currentConfigPath}" + fi + ''; + setupWorkDir = writeScript "setup-work-dirs" '' + # Link _diag dir + ln -s "$LOGS_DIRECTORY" "$WORK_DIRECTORY/_diag" - InaccessiblePaths = [ - # Token file path given in the configuration, if visible to the service - "-${cfg.tokenFile}" - # Token file in the state directory - "${stateDir}/${currentConfigTokenFilename}" - ]; + # Link the runner credentials to the work dir + ln -s "$STATE_DIRECTORY"/{${lib.concatStringsSep "," runnerCredFiles}} "$WORK_DIRECTORY/" + ''; + in + map (x: "${x} ${escapeShellArgs [ stateDir workDir logsDir ]}") [ + "+${unconfigureRunner}" # runs as root + configureRunner + setupWorkDir + ]; - KillSignal = "SIGINT"; + # If running in ephemeral mode, restart the service on-exit (i.e., successful de-registration of the runner) + # to trigger a fresh registration. + Restart = if cfg.ephemeral then "on-success" else "no"; + # If the runner exits with `ReturnCode.RetryableError = 2`, always restart the service: + # https://github.com/actions/runner/blob/40ed7f8/src/Runner.Common/Constants.cs#L146 + RestartForceExitStatus = [ 2 ]; - # Hardening (may overlap with DynamicUser=) - # The following options are only for optimizing: - # systemd-analyze security github-runner - AmbientCapabilities = mkBefore [ "" ]; - CapabilityBoundingSet = mkBefore [ "" ]; - # ProtectClock= adds DeviceAllow=char-rtc r - DeviceAllow = mkBefore [ "" ]; - NoNewPrivileges = mkDefault true; - PrivateDevices = mkDefault true; - PrivateMounts = mkDefault true; - PrivateTmp = mkDefault true; - PrivateUsers = mkDefault true; - ProtectClock = mkDefault true; - ProtectControlGroups = mkDefault true; - ProtectHome = mkDefault true; - ProtectHostname = mkDefault true; - ProtectKernelLogs = mkDefault true; - ProtectKernelModules = mkDefault true; - ProtectKernelTunables = mkDefault true; - ProtectSystem = mkDefault "strict"; - RemoveIPC = mkDefault true; - RestrictNamespaces = mkDefault true; - RestrictRealtime = mkDefault true; - RestrictSUIDSGID = mkDefault true; - UMask = mkDefault "0066"; - ProtectProc = mkDefault "invisible"; - SystemCallFilter = mkBefore [ - "~@clock" - "~@cpu-emulation" - "~@module" - "~@mount" - "~@obsolete" - "~@raw-io" - "~@reboot" - "~capset" - "~setdomainname" - "~sethostname" - ]; - RestrictAddressFamilies = mkBefore [ "AF_INET" "AF_INET6" "AF_UNIX" "AF_NETLINK" ]; + # Contains _diag + LogsDirectory = [ systemdDir ]; + # Default RUNNER_ROOT which contains ephemeral Runner data + RuntimeDirectory = [ systemdDir ]; + # Home of persistent runner data, e.g., credentials + StateDirectory = [ systemdDir ]; + StateDirectoryMode = "0700"; + WorkingDirectory = workDir; - BindPaths = lib.optionals (cfg.workDir != null) [ cfg.workDir ]; + InaccessiblePaths = [ + # Token file path given in the configuration, if visible to the service + "-${cfg.tokenFile}" + # Token file in the state directory + "${stateDir}/${currentConfigTokenFilename}" + ]; + + KillSignal = "SIGINT"; + + # Hardening (may overlap with DynamicUser=) + # The following options are only for optimizing: + # systemd-analyze security github-runner + AmbientCapabilities = mkBefore [ "" ]; + CapabilityBoundingSet = mkBefore [ "" ]; + # ProtectClock= adds DeviceAllow=char-rtc r + DeviceAllow = mkBefore [ "" ]; + NoNewPrivileges = mkDefault true; + PrivateDevices = mkDefault true; + PrivateMounts = mkDefault true; + PrivateTmp = mkDefault true; + PrivateUsers = mkDefault true; + ProtectClock = mkDefault true; + ProtectControlGroups = mkDefault true; + ProtectHome = mkDefault true; + ProtectHostname = mkDefault true; + ProtectKernelLogs = mkDefault true; + ProtectKernelModules = mkDefault true; + ProtectKernelTunables = mkDefault true; + ProtectSystem = mkDefault "strict"; + RemoveIPC = mkDefault true; + RestrictNamespaces = mkDefault true; + RestrictRealtime = mkDefault true; + RestrictSUIDSGID = mkDefault true; + UMask = mkDefault "0066"; + ProtectProc = mkDefault "invisible"; + SystemCallFilter = mkBefore [ + "~@clock" + "~@cpu-emulation" + "~@module" + "~@mount" + "~@obsolete" + "~@raw-io" + "~@reboot" + "~capset" + "~setdomainname" + "~sethostname" + ]; + RestrictAddressFamilies = mkBefore [ "AF_INET" "AF_INET6" "AF_UNIX" "AF_NETLINK" ]; + + BindPaths = lib.optionals (cfg.workDir != null) [ cfg.workDir ]; - # Needs network access - PrivateNetwork = mkDefault false; - # Cannot be true due to Node - MemoryDenyWriteExecute = mkDefault false; + # Needs network access + PrivateNetwork = mkDefault false; + # Cannot be true due to Node + MemoryDenyWriteExecute = mkDefault false; - # The more restrictive "pid" option makes `nix` commands in CI emit - # "GC Warning: Couldn't read /proc/stat" - # You may want to set this to "pid" if not using `nix` commands - ProcSubset = mkDefault "all"; - # Coverage programs for compiled code such as `cargo-tarpaulin` disable - # ASLR (address space layout randomization) which requires the - # `personality` syscall - # You may want to set this to `true` if not using coverage tooling on - # compiled code - LockPersonality = mkDefault false; + # The more restrictive "pid" option makes `nix` commands in CI emit + # "GC Warning: Couldn't read /proc/stat" + # You may want to set this to "pid" if not using `nix` commands + ProcSubset = mkDefault "all"; + # Coverage programs for compiled code such as `cargo-tarpaulin` disable + # ASLR (address space layout randomization) which requires the + # `personality` syscall + # You may want to set this to `true` if not using coverage tooling on + # compiled code + LockPersonality = mkDefault false; - # Note that this has some interactions with the User setting; so you may - # want to consult the systemd docs if using both. - DynamicUser = mkDefault true; + # Note that this has some interactions with the User setting; so you may + # want to consult the systemd docs if using both. + DynamicUser = mkDefault true; + } + (mkIf (cfg.user != null) { User = cfg.user; }) + cfg.serviceOverrides + ]; } - (mkIf (cfg.user != null) { User = cfg.user; }) - cfg.serviceOverrides - ]; + ); } |