{ config, pkgs, ... }:
with pkgs.lib;
let
cfg = config.services.hydra;
baseDir = "/var/lib/hydra";
hydraConf = pkgs.writeScript "hydra.conf"
''
using_frontend_proxy 1
base_uri ${cfg.hydraURL}
notification_sender ${cfg.notificationSender}
max_servers 25
'';
env =
{ NIX_REMOTE = "daemon";
HYDRA_DBI = cfg.dbi;
HYDRA_CONFIG = "${baseDir}/data/hydra.conf";
HYDRA_DATA = "${baseDir}/data";
HYDRA_PORT = "${toString cfg.port}";
OPENSSL_X509_CERT_FILE = "/etc/ssl/certs/ca-bundle.crt";
GIT_SSL_CAINFO = "/etc/ssl/certs/ca-bundle.crt";
};
serverEnv = env //
{ HYDRA_LOGO = if cfg.logo != null then cfg.logo else "";
HYDRA_TRACKER = cfg.tracker;
} // (optionalAttrs cfg.debugServer { DBIC_TRACE = 1; });
in
{
###### interface
options = {
services.hydra = rec {
enable = mkOption {
default = false;
description = ''
Whether to run Hydra services.
'';
};
dbi = mkOption {
default = "dbi:Pg:dbname=hydra;host=localhost;user=hydra;";
example = "dbi:SQLite:/home/hydra/db/hydra.sqlite";
description = ''
The DBI string for Hydra database connection.
'';
};
hydra = mkOption {
#default = pkgs.hydra;
description = ''
Location of hydra
'';
};
hydraURL = mkOption {
description = ''
The base URL for the Hydra webserver instance. Used for links in emails.
'';
};
port = mkOption {
default = 3000;
description = ''
TCP port the web server should listen to.
'';
};
minimumDiskFree = mkOption {
default = 5;
description = ''
Threshold of minimum disk space (G) to determine if queue runner should run or not.
'';
};
minimumDiskFreeEvaluator = mkOption {
default = 2;
description = ''
Threshold of minimum disk space (G) to determine if evaluator should run or not.
'';
};
notificationSender = mkOption {
description = ''
Sender email address used for email notifications.
'';
};
tracker = mkOption {
default = "";
description = ''
Piece of HTML that is included on all pages.
'';
};
logo = mkOption {
default = null;
description = ''
File name of an alternate logo to be displayed on the web pages.
'';
};
useWAL = mkOption {
default = true;
description = ''
Whether to use SQLite's Write-Ahead Logging, which may improve performance.
'';
};
debugServer = mkOption {
default = false;
type = types.bool;
description = "Whether to run the server in debug mode";
};
};
};
###### implementation
config = mkIf cfg.enable {
environment.systemPackages = [ cfg.hydra ];
users.extraUsers.hydra =
{ description = "Hydra";
home = baseDir;
createHome = true;
useDefaultShell = true;
};
nix.extraOptions = ''
gc-keep-outputs = true
gc-keep-derivations = true
# The default (`true') slows Nix down a lot since the build farm
# has so many GC roots.
gc-check-reachability = false
# Hydra needs caching of build failures.
build-cache-failure = true
build-poll-interval = 10
# Online log compression makes it impossible to get the tail of
# builds that are in progress.
build-compress-log = false
use-sqlite-wal = ${if cfg.useWAL then "true" else "false"}
'';
systemd.services."hydra-init" =
{ wantedBy = [ "multi-user.target" ];
requires = [ "postgresql.service" ];
after = [ "postgresql.service" ];
environment = env;
script = ''
mkdir -p ${baseDir}/data
chown hydra ${baseDir}/data
ln -sf ${hydraConf} ${baseDir}/data/hydra.conf
pass=$(HOME=/root ${pkgs.openssl}/bin/openssl rand -base64 32)
if [ ! -f ${baseDir}/.pgpass ]; then
${config.services.postgresql.package}/bin/psql postgres << EOF
CREATE USER hydra PASSWORD '$pass';
EOF
${config.services.postgresql.package}/bin/createdb -O hydra hydra
cat > ${baseDir}/.pgpass-tmp << EOF
localhost:*:hydra:hydra:$pass
EOF
chown hydra ${baseDir}/.pgpass-tmp
chmod 600 ${baseDir}/.pgpass-tmp
mv ${baseDir}/.pgpass-tmp ${baseDir}/.pgpass
fi
${pkgs.shadow}/bin/su hydra -c ${cfg.hydra}/bin/hydra-init
${config.services.postgresql.package}/bin/psql hydra << EOF
BEGIN;
INSERT INTO Users(userName, emailAddress, password) VALUES ('admin', '${cfg.notificationSender}', '$(echo -n $pass | sha1sum | cut -c1-40)');
INSERT INTO UserRoles(userName, role) values('admin', 'admin');
COMMIT;
EOF
'';
serviceConfig.Type = "oneshot";
serviceConfig.RemainAfterExit = true;
};
systemd.services."hydra-server" =
{ wantedBy = [ "multi-user.target" ];
wants = [ "hydra-init.service" ];
after = [ "hydra-init.service" ];
environment = serverEnv;
serviceConfig =
{ ExecStart = "@${cfg.hydra}/bin/hydra-server hydra-server -f -h \* --max_spare_servers 5 --max_servers 25 --max_requests 100${optionalString cfg.debugServer " -d"}";
User = "hydra";
Restart = "always";
};
};
systemd.services."hydra-queue-runner" =
{ wantedBy = [ "multi-user.target" ];
wants = [ "hydra-init.service" ];
after = [ "hydra-init.service" "network.target" ];
path = [ pkgs.nettools ];
environment = env;
serviceConfig =
{ ExecStartPre = "${cfg.hydra}/bin/hydra-queue-runner --unlock";
ExecStart = "@${cfg.hydra}/bin/hydra-queue-runner hydra-queue-runner";
User = "hydra";
Restart = "always";
};
};
systemd.services."hydra-evaluator" =
{ wantedBy = [ "multi-user.target" ];
wants = [ "hydra-init.service" ];
after = [ "hydra-init.service" "network.target" ];
path = [ pkgs.nettools ];
environment = env;
serviceConfig =
{ ExecStart = "@${cfg.hydra}/bin/hydra-evaluator hydra-evaluator";
User = "hydra";
Restart = "always";
};
};
systemd.services."hydra-update-gc-roots" =
{ wants = [ "hydra-init.service" ];
after = [ "hydra-init.service" ];
environment = env;
serviceConfig =
{ ExecStart = "@${cfg.hydra}/bin/hydra-update-gc-roots hydra-update-gc-roots";
User = "hydra";
};
};
services.cron.systemCronJobs =
let
# If there is less than ... GiB of free disk space, stop the queue
# to prevent builds from failing or aborting.
checkSpace = pkgs.writeScript "hydra-check-space"
''
#! ${pkgs.stdenv.shell}
if [ $(($(stat -f -c '%a' /nix/store) * $(stat -f -c '%S' /nix/store))) -lt $((${toString cfg.minimumDiskFree} * 1024**3)) ]; then
systemctl stop hydra-queue-runner
fi
if [ $(($(stat -f -c '%a' /nix/store) * $(stat -f -c '%S' /nix/store))) -lt $((${toString cfg.minimumDiskFreeEvaluator} * 1024**3)) ]; then
systemctl stop hydra-evaluator
fi
'';
compressLogs = pkgs.writeScript "compress-logs" ''
#! ${pkgs.stdenv.shell} -e
touch -d 'last month' r
find /nix/var/log/nix/drvs -type f -a ! -newer r -name '*.drv' | xargs bzip2 -v
'';
in
[ "*/5 * * * * root ${checkSpace} &> ${baseDir}/data/checkspace.log"
"15 5 * * * root ${compressLogs} &> ${baseDir}/data/compress.log"
"15 2 * * * root ${pkgs.systemd}/bin/systemctl start hydra-update-gc-roots.service"
];
};
}