nixpkgs/nixos/modules/services/databases/mysql.nix
2022-12-08 17:52:52 +01:00

522 lines
18 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.mysql;
isMariaDB = lib.getName cfg.package == lib.getName pkgs.mariadb;
mysqldOptions =
"--user=${cfg.user} --datadir=${cfg.dataDir} --basedir=${cfg.package}";
format = pkgs.formats.ini { listsAsDuplicateKeys = true; };
configFile = format.generate "my.cnf" cfg.settings;
in
{
imports = [
(mkRemovedOptionModule [ "services" "mysql" "pidDir" ] "Don't wait for pidfiles, describe dependencies through systemd.")
(mkRemovedOptionModule [ "services" "mysql" "rootPassword" ] "Use socket authentication or set the password outside of the nix store.")
(mkRemovedOptionModule [ "services" "mysql" "extraOptions" ] "Use services.mysql.settings.mysqld instead.")
(mkRemovedOptionModule [ "services" "mysql" "bind" ] "Use services.mysql.settings.mysqld.bind-address instead.")
(mkRemovedOptionModule [ "services" "mysql" "port" ] "Use services.mysql.settings.mysqld.port instead.")
];
###### interface
options = {
services.mysql = {
enable = mkEnableOption (lib.mdDoc "MySQL server");
package = mkOption {
type = types.package;
example = literalExpression "pkgs.mariadb";
description = lib.mdDoc ''
Which MySQL derivation to use. MariaDB packages are supported too.
'';
};
user = mkOption {
type = types.str;
default = "mysql";
description = lib.mdDoc ''
User account under which MySQL runs.
::: {.note}
If left as the default value this user will automatically be created
on system activation, otherwise you are responsible for
ensuring the user exists before the MySQL service starts.
:::
'';
};
group = mkOption {
type = types.str;
default = "mysql";
description = lib.mdDoc ''
Group account under which MySQL runs.
::: {.note}
If left as the default value this group will automatically be created
on system activation, otherwise you are responsible for
ensuring the user exists before the MySQL service starts.
:::
'';
};
dataDir = mkOption {
type = types.path;
example = "/var/lib/mysql";
description = lib.mdDoc ''
The data directory for MySQL.
::: {.note}
If left as the default value of `/var/lib/mysql` this directory will automatically be created before the MySQL
server starts, otherwise you are responsible for ensuring the directory exists with appropriate ownership and permissions.
:::
'';
};
configFile = mkOption {
type = types.path;
default = configFile;
defaultText = ''
A configuration file automatically generated by NixOS.
'';
description = lib.mdDoc ''
Override the configuration file used by MySQL. By default,
NixOS generates one automatically from {option}`services.mysql.settings`.
'';
example = literalExpression ''
pkgs.writeText "my.cnf" '''
[mysqld]
datadir = /var/lib/mysql
bind-address = 127.0.0.1
port = 3336
!includedir /etc/mysql/conf.d/
''';
'';
};
settings = mkOption {
type = format.type;
default = {};
description = lib.mdDoc ''
MySQL configuration. Refer to
<https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html>,
<https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html>,
and <https://mariadb.com/kb/en/server-system-variables/>
for details on supported values.
::: {.note}
MySQL configuration options such as `--quick` should be treated as
boolean options and provided values such as `true`, `false`,
`1`, or `0`. See the provided example below.
:::
'';
example = literalExpression ''
{
mysqld = {
key_buffer_size = "6G";
table_cache = 1600;
log-error = "/var/log/mysql_err.log";
plugin-load-add = [ "server_audit" "ed25519=auth_ed25519" ];
};
mysqldump = {
quick = true;
max_allowed_packet = "16M";
};
}
'';
};
initialDatabases = mkOption {
type = types.listOf (types.submodule {
options = {
name = mkOption {
type = types.str;
description = lib.mdDoc ''
The name of the database to create.
'';
};
schema = mkOption {
type = types.nullOr types.path;
default = null;
description = lib.mdDoc ''
The initial schema of the database; if null (the default),
an empty database is created.
'';
};
};
});
default = [];
description = lib.mdDoc ''
List of database names and their initial schemas that should be used to create databases on the first startup
of MySQL. The schema attribute is optional: If not specified, an empty database is created.
'';
example = literalExpression ''
[
{ name = "foodatabase"; schema = ./foodatabase.sql; }
{ name = "bardatabase"; }
]
'';
};
initialScript = mkOption {
type = types.nullOr types.path;
default = null;
description = lib.mdDoc "A file containing SQL statements to be executed on the first startup. Can be used for granting certain permissions on the database.";
};
ensureDatabases = mkOption {
type = types.listOf types.str;
default = [];
description = lib.mdDoc ''
Ensures that the specified databases exist.
This option will never delete existing databases, especially not when the value of this
option is changed. This means that databases created once through this option or
otherwise have to be removed manually.
'';
example = [
"nextcloud"
"matomo"
];
};
ensureUsers = mkOption {
type = types.listOf (types.submodule {
options = {
name = mkOption {
type = types.str;
description = lib.mdDoc ''
Name of the user to ensure.
'';
};
ensurePermissions = mkOption {
type = types.attrsOf types.str;
default = {};
description = lib.mdDoc ''
Permissions to ensure for the user, specified as attribute set.
The attribute names specify the database and tables to grant the permissions for,
separated by a dot. You may use wildcards here.
The attribute values specfiy the permissions to grant.
You may specify one or multiple comma-separated SQL privileges here.
For more information on how to specify the target
and on which privileges exist, see the
[GRANT syntax](https://mariadb.com/kb/en/library/grant/).
The attributes are used as `GRANT ''${attrName} ON ''${attrValue}`.
'';
example = literalExpression ''
{
"database.*" = "ALL PRIVILEGES";
"*.*" = "SELECT, LOCK TABLES";
}
'';
};
};
});
default = [];
description = lib.mdDoc ''
Ensures that the specified users exist and have at least the ensured permissions.
The MySQL users will be identified using Unix socket authentication. This authenticates the Unix user with the
same name only, and that without the need for a password.
This option will never delete existing users or remove permissions, especially not when the value of this
option is changed. This means that users created and permissions assigned once through this option or
otherwise have to be removed manually.
'';
example = literalExpression ''
[
{
name = "nextcloud";
ensurePermissions = {
"nextcloud.*" = "ALL PRIVILEGES";
};
}
{
name = "backup";
ensurePermissions = {
"*.*" = "SELECT, LOCK TABLES";
};
}
]
'';
};
replication = {
role = mkOption {
type = types.enum [ "master" "slave" "none" ];
default = "none";
description = lib.mdDoc "Role of the MySQL server instance.";
};
serverId = mkOption {
type = types.int;
default = 1;
description = lib.mdDoc "Id of the MySQL server instance. This number must be unique for each instance.";
};
masterHost = mkOption {
type = types.str;
description = lib.mdDoc "Hostname of the MySQL master server.";
};
slaveHost = mkOption {
type = types.str;
description = lib.mdDoc "Hostname of the MySQL slave server.";
};
masterUser = mkOption {
type = types.str;
description = lib.mdDoc "Username of the MySQL replication user.";
};
masterPassword = mkOption {
type = types.str;
description = lib.mdDoc "Password of the MySQL replication user.";
};
masterPort = mkOption {
type = types.port;
default = 3306;
description = lib.mdDoc "Port number on which the MySQL master server runs.";
};
};
};
};
###### implementation
config = mkIf cfg.enable {
services.mysql.dataDir =
mkDefault (if versionAtLeast config.system.stateVersion "17.09" then "/var/lib/mysql"
else "/var/mysql");
services.mysql.settings.mysqld = mkMerge [
{
datadir = cfg.dataDir;
port = mkDefault 3306;
}
(mkIf (cfg.replication.role == "master" || cfg.replication.role == "slave") {
log-bin = "mysql-bin-${toString cfg.replication.serverId}";
log-bin-index = "mysql-bin-${toString cfg.replication.serverId}.index";
relay-log = "mysql-relay-bin";
server-id = cfg.replication.serverId;
binlog-ignore-db = [ "information_schema" "performance_schema" "mysql" ];
})
(mkIf (!isMariaDB) {
plugin-load-add = "auth_socket.so";
})
];
users.users = optionalAttrs (cfg.user == "mysql") {
mysql = {
description = "MySQL server user";
group = cfg.group;
uid = config.ids.uids.mysql;
};
};
users.groups = optionalAttrs (cfg.group == "mysql") {
mysql.gid = config.ids.gids.mysql;
};
environment.systemPackages = [ cfg.package ];
environment.etc."my.cnf".source = cfg.configFile;
systemd.services.mysql = {
description = "MySQL Server";
after = [ "network.target" ];
wantedBy = [ "multi-user.target" ];
restartTriggers = [ cfg.configFile ];
unitConfig.RequiresMountsFor = cfg.dataDir;
path = [
# Needed for the mysql_install_db command in the preStart script
# which calls the hostname command.
pkgs.nettools
];
preStart = if isMariaDB then ''
if ! test -e ${cfg.dataDir}/mysql; then
${cfg.package}/bin/mysql_install_db --defaults-file=/etc/my.cnf ${mysqldOptions}
touch ${cfg.dataDir}/mysql_init
fi
'' else ''
if ! test -e ${cfg.dataDir}/mysql; then
${cfg.package}/bin/mysqld --defaults-file=/etc/my.cnf ${mysqldOptions} --initialize-insecure
touch ${cfg.dataDir}/mysql_init
fi
'';
script = ''
# https://mariadb.com/kb/en/getting-started-with-mariadb-galera-cluster/#systemd-and-galera-recovery
if test -n "''${_WSREP_START_POSITION}"; then
if test -e "${cfg.package}/bin/galera_recovery"; then
VAR=$(cd ${cfg.package}/bin/..; ${cfg.package}/bin/galera_recovery); [[ $? -eq 0 ]] && export _WSREP_START_POSITION=$VAR || exit 1
fi
fi
# The last two environment variables are used for starting Galera clusters
exec ${cfg.package}/bin/mysqld --defaults-file=/etc/my.cnf ${mysqldOptions} $_WSREP_NEW_CLUSTER $_WSREP_START_POSITION
'';
postStart = let
# The super user account to use on *first* run of MySQL server
superUser = if isMariaDB then cfg.user else "root";
in ''
${optionalString (!isMariaDB) ''
# Wait until the MySQL server is available for use
count=0
while [ ! -e /run/mysqld/mysqld.sock ]
do
if [ $count -eq 30 ]
then
echo "Tried 30 times, giving up..."
exit 1
fi
echo "MySQL daemon not yet started. Waiting for 1 second..."
count=$((count++))
sleep 1
done
''}
if [ -f ${cfg.dataDir}/mysql_init ]
then
# While MariaDB comes with a 'mysql' super user account since 10.4.x, MySQL does not
# Since we don't want to run this service as 'root' we need to ensure the account exists on first run
( echo "CREATE USER IF NOT EXISTS '${cfg.user}'@'localhost' IDENTIFIED WITH ${if isMariaDB then "unix_socket" else "auth_socket"};"
echo "GRANT ALL PRIVILEGES ON *.* TO '${cfg.user}'@'localhost' WITH GRANT OPTION;"
) | ${cfg.package}/bin/mysql -u ${superUser} -N
${concatMapStrings (database: ''
# Create initial databases
if ! test -e "${cfg.dataDir}/${database.name}"; then
echo "Creating initial database: ${database.name}"
( echo 'create database `${database.name}`;'
${optionalString (database.schema != null) ''
echo 'use `${database.name}`;'
# TODO: this silently falls through if database.schema does not exist,
# we should catch this somehow and exit, but can't do it here because we're in a subshell.
if [ -f "${database.schema}" ]
then
cat ${database.schema}
elif [ -d "${database.schema}" ]
then
cat ${database.schema}/mysql-databases/*.sql
fi
''}
) | ${cfg.package}/bin/mysql -u ${superUser} -N
fi
'') cfg.initialDatabases}
${optionalString (cfg.replication.role == "master")
''
# Set up the replication master
( echo "use mysql;"
echo "CREATE USER '${cfg.replication.masterUser}'@'${cfg.replication.slaveHost}' IDENTIFIED WITH mysql_native_password;"
echo "SET PASSWORD FOR '${cfg.replication.masterUser}'@'${cfg.replication.slaveHost}' = PASSWORD('${cfg.replication.masterPassword}');"
echo "GRANT REPLICATION SLAVE ON *.* TO '${cfg.replication.masterUser}'@'${cfg.replication.slaveHost}';"
) | ${cfg.package}/bin/mysql -u ${superUser} -N
''}
${optionalString (cfg.replication.role == "slave")
''
# Set up the replication slave
( echo "stop slave;"
echo "change master to master_host='${cfg.replication.masterHost}', master_user='${cfg.replication.masterUser}', master_password='${cfg.replication.masterPassword}';"
echo "start slave;"
) | ${cfg.package}/bin/mysql -u ${superUser} -N
''}
${optionalString (cfg.initialScript != null)
''
# Execute initial script
# using toString to avoid copying the file to nix store if given as path instead of string,
# as it might contain credentials
cat ${toString cfg.initialScript} | ${cfg.package}/bin/mysql -u ${superUser} -N
''}
rm ${cfg.dataDir}/mysql_init
fi
${optionalString (cfg.ensureDatabases != []) ''
(
${concatMapStrings (database: ''
echo "CREATE DATABASE IF NOT EXISTS \`${database}\`;"
'') cfg.ensureDatabases}
) | ${cfg.package}/bin/mysql -N
''}
${concatMapStrings (user:
''
( echo "CREATE USER IF NOT EXISTS '${user.name}'@'localhost' IDENTIFIED WITH ${if isMariaDB then "unix_socket" else "auth_socket"};"
${concatStringsSep "\n" (mapAttrsToList (database: permission: ''
echo "GRANT ${permission} ON ${database} TO '${user.name}'@'localhost';"
'') user.ensurePermissions)}
) | ${cfg.package}/bin/mysql -N
'') cfg.ensureUsers}
'';
serviceConfig = mkMerge [
{
Type = if isMariaDB then "notify" else "simple";
Restart = "on-abort";
RestartSec = "5s";
# User and group
User = cfg.user;
Group = cfg.group;
# Runtime directory and mode
RuntimeDirectory = "mysqld";
RuntimeDirectoryMode = "0755";
# Access write directories
ReadWritePaths = [ cfg.dataDir ];
# Capabilities
CapabilityBoundingSet = "";
# Security
NoNewPrivileges = true;
# Sandboxing
ProtectSystem = "strict";
ProtectHome = true;
PrivateTmp = true;
PrivateDevices = true;
ProtectHostname = true;
ProtectKernelTunables = true;
ProtectKernelModules = true;
ProtectControlGroups = true;
RestrictAddressFamilies = [ "AF_UNIX" "AF_INET" "AF_INET6" ];
LockPersonality = true;
MemoryDenyWriteExecute = true;
RestrictRealtime = true;
RestrictSUIDSGID = true;
PrivateMounts = true;
# System Call Filtering
SystemCallArchitectures = "native";
}
(mkIf (cfg.dataDir == "/var/lib/mysql") {
StateDirectory = "mysql";
StateDirectoryMode = "0700";
})
];
};
};
}