mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-12-30 17:43:42 +00:00
6d8391a3ce
Similar to the `user` option, the added `group` option sets the group of the executing process. If not `null`, it also sets `DynamicUser=false`. In case `user` is set to `null` (the default), systemd would run the service as root implicitly. As this is dangerous and most certainly not what users want, we force them to set `user = "root"` explicitly if that's really their intention. That's achieved through an assertion.
300 lines
13 KiB
Nix
300 lines
13 KiB
Nix
{ config
|
|
, lib
|
|
, pkgs
|
|
, ...
|
|
}:
|
|
|
|
with lib;
|
|
{
|
|
config.assertions = flatten (
|
|
flip mapAttrsToList config.services.github-runners (name: cfg: map (mkIf cfg.enable) [
|
|
{
|
|
assertion = !cfg.noDefaultLabels || (cfg.extraLabels != [ ]);
|
|
message = "`services.github-runners.${name}`: The `extraLabels` option is mandatory if `noDefaultLabels` is set";
|
|
}
|
|
{
|
|
assertion = cfg.group == null || cfg.user != null;
|
|
message = ''`services.github-runners.${name}`: Setting `group` while leaving `user` unset runs the service as `root`. If this is really what you want, set `user = "root"` explicitly'';
|
|
}
|
|
])
|
|
);
|
|
|
|
config.systemd.services = flip mapAttrs' config.services.github-runners (name: cfg:
|
|
let
|
|
svcName = "github-runner-${name}";
|
|
systemdDir = "github-runner/${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/${systemdDir}";
|
|
# Name of file stored in service state directory
|
|
currentConfigTokenFilename = ".current-token";
|
|
|
|
workDir = if cfg.workDir == null then runtimeDir else cfg.workDir;
|
|
# Support old github-runner versions which don't have the `nodeRuntimes` arg yet.
|
|
package = cfg.package.override (old: optionalAttrs (hasAttr "nodeRuntimes" old) { inherit (cfg) nodeRuntimes; });
|
|
in
|
|
nameValuePair svcName {
|
|
description = "GitHub Actions runner";
|
|
|
|
wantedBy = [ "multi-user.target" ];
|
|
wants = [ "network-online.target" ];
|
|
after = [ "network.target" "network-online.target" ];
|
|
|
|
environment = {
|
|
HOME = workDir;
|
|
RUNNER_ROOT = stateDir;
|
|
} // cfg.extraEnvironment;
|
|
|
|
path = (with pkgs; [
|
|
bash
|
|
coreutils
|
|
git
|
|
gnutar
|
|
gzip
|
|
]) ++ [
|
|
config.nix.package
|
|
] ++ cfg.extraPackages;
|
|
|
|
serviceConfig = mkMerge [
|
|
{
|
|
ExecStart = "${package}/bin/Runner.Listener run --startuptype service";
|
|
|
|
# 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
|
|
|
|
STATE_DIRECTORY="$1"
|
|
WORK_DIRECTORY="$2"
|
|
LOGS_DIRECTORY="$3"
|
|
|
|
${lines}
|
|
'';
|
|
runnerRegistrationConfig = getAttrs [
|
|
"ephemeral"
|
|
"extraLabels"
|
|
"name"
|
|
"noDefaultLabels"
|
|
"runnerGroup"
|
|
"tokenFile"
|
|
"url"
|
|
"workDir"
|
|
]
|
|
cfg;
|
|
newConfigPath = builtins.toFile "${svcName}-config.json" (builtins.toJSON runnerRegistrationConfig);
|
|
currentConfigPath = "$STATE_DIRECTORY/.nixos-current-config.json";
|
|
newConfigTokenPath = "$STATE_DIRECTORY/.new-token";
|
|
currentConfigTokenPath = "$STATE_DIRECTORY/${currentConfigTokenFilename}";
|
|
|
|
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" "$WORK_DIRECTORY/_diag"
|
|
|
|
# Link the runner credentials to the work dir
|
|
ln -s "$STATE_DIRECTORY"/{${lib.concatStringsSep "," runnerCredFiles}} "$WORK_DIRECTORY/"
|
|
'';
|
|
in
|
|
map (x: "${x} ${escapeShellArgs [ stateDir workDir logsDir ]}") [
|
|
"+${unconfigureRunner}" # runs as root
|
|
configureRunner
|
|
setupWorkDir
|
|
];
|
|
|
|
# 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 ];
|
|
|
|
# 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;
|
|
|
|
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;
|
|
|
|
# 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;
|
|
|
|
DynamicUser = mkDefault true;
|
|
}
|
|
(mkIf (cfg.user != null) {
|
|
DynamicUser = false;
|
|
User = cfg.user;
|
|
})
|
|
(mkIf (cfg.group != null) {
|
|
DynamicUser = false;
|
|
Group = cfg.group;
|
|
})
|
|
cfg.serviceOverrides
|
|
];
|
|
}
|
|
);
|
|
}
|