nixpkgs/nixos/modules/services/databases/mysql.nix
Peter Hoeg 5b468ea6b1 nixos mysql: make start-up more robust (#41010)
1) Change start-type to ```notify``` when running MariaDB so that we don't have to busy-wait for the
socket to appear.

2) Do not manually create the directory under /run as we can get systemd to do
that for us. This opens up the possibility later for not having to launch as root.
2018-05-24 16:42:16 +02:00

374 lines
12 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.mysql;
mysql = cfg.package;
isMariaDB =
let
pName = _p: (builtins.parseDrvName (_p.name)).name;
in pName mysql == pName pkgs.mariadb;
pidFile = "${cfg.pidDir}/mysqld.pid";
mysqldOptions =
"--user=${cfg.user} --datadir=${cfg.dataDir} --basedir=${mysql} " +
"--pid-file=${pidFile}";
myCnf = pkgs.writeText "my.cnf"
''
[mysqld]
port = ${toString cfg.port}
${optionalString (cfg.bind != null) "bind-address = ${cfg.bind}" }
${optionalString (cfg.replication.role == "master" || cfg.replication.role == "slave") "log-bin=mysql-bin"}
${optionalString (cfg.replication.role == "master" || cfg.replication.role == "slave") "server-id = ${toString cfg.replication.serverId}"}
${optionalString (cfg.ensureUsers != [])
''
plugin-load-add = auth_socket.so
''}
${cfg.extraOptions}
'';
in
{
###### interface
options = {
services.mysql = {
enable = mkOption {
type = types.bool;
default = false;
description = "
Whether to enable the MySQL server.
";
};
package = mkOption {
type = types.package;
example = literalExample "pkgs.mysql";
description = "
Which MySQL derivation to use. MariaDB packages are supported too.
";
};
bind = mkOption {
type = types.nullOr types.str;
default = null;
example = literalExample "0.0.0.0";
description = "Address to bind to. The default is to bind to all addresses";
};
port = mkOption {
type = types.int;
default = 3306;
description = "Port of MySQL";
};
user = mkOption {
type = types.str;
default = "mysql";
description = "User account under which MySQL runs";
};
dataDir = mkOption {
type = types.path;
example = "/var/lib/mysql";
description = "Location where MySQL stores its table files";
};
pidDir = mkOption {
default = "/run/mysqld";
description = "Location of the file which stores the PID of the MySQL server";
};
extraOptions = mkOption {
type = types.lines;
default = "";
example = ''
key_buffer_size = 6G
table_cache = 1600
log-error = /var/log/mysql_err.log
'';
description = ''
Provide extra options to the MySQL configuration file.
Please note, that these options are added to the
<literal>[mysqld]</literal> section so you don't need to explicitly
state it again.
'';
};
initialDatabases = mkOption {
default = [];
description = ''
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 = [
{ name = "foodatabase"; schema = literalExample "./foodatabase.sql"; }
{ name = "bardatabase"; }
];
};
initialScript = mkOption {
default = null;
description = "A file containing SQL statements to be executed on the first startup. Can be used for granting certain permissions on the database";
};
ensureDatabases = mkOption {
default = [];
description = ''
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 {
default = [];
description = ''
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 = [
{
name = "nextcloud";
ensurePermissions = {
"nextcloud.*" = "ALL PRIVILEGES";
};
}
{
name = "backup";
ensurePermissions = {
"*.*" = "SELECT, LOCK TABLES";
};
}
];
};
# FIXME: remove this option; it's a really bad idea.
rootPassword = mkOption {
default = null;
description = "Path to a file containing the root password, modified on the first startup. Not specifying a root password will leave the root password empty.";
};
replication = {
role = mkOption {
type = types.enum [ "master" "slave" "none" ];
default = "none";
description = "Role of the MySQL server instance.";
};
serverId = mkOption {
type = types.int;
default = 1;
description = "Id of the MySQL server instance. This number must be unique for each instance";
};
masterHost = mkOption {
type = types.str;
description = "Hostname of the MySQL master server";
};
slaveHost = mkOption {
type = types.str;
description = "Hostname of the MySQL slave server";
};
masterUser = mkOption {
type = types.str;
description = "Username of the MySQL replication user";
};
masterPassword = mkOption {
type = types.str;
description = "Password of the MySQL replication user";
};
masterPort = mkOption {
type = types.int;
default = 3306;
description = "Port number on which the MySQL master server runs";
};
};
};
};
###### implementation
config = mkIf config.services.mysql.enable {
services.mysql.dataDir =
mkDefault (if versionAtLeast config.system.nixos.stateVersion "17.09" then "/var/lib/mysql"
else "/var/mysql");
users.extraUsers.mysql = {
description = "MySQL server user";
group = "mysql";
uid = config.ids.uids.mysql;
};
users.extraGroups.mysql.gid = config.ids.gids.mysql;
environment.systemPackages = [mysql];
systemd.services.mysql = let
hasNotify = (cfg.package == pkgs.mariadb);
in {
description = "MySQL Server";
after = [ "network.target" ];
wantedBy = [ "multi-user.target" ];
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 ! test -e ${cfg.dataDir}/mysql; then
mkdir -m 0700 -p ${cfg.dataDir}
chown -R ${cfg.user} ${cfg.dataDir}
${mysql}/bin/mysql_install_db ${mysqldOptions}
touch /tmp/mysql_init
fi
mkdir -m 0755 -p ${cfg.pidDir}
chown -R ${cfg.user} ${cfg.pidDir}
'';
serviceConfig = {
Type = if hasNotify then "notify" else "simple";
RuntimeDirectory = "mysqld";
ExecStart = "${mysql}/bin/mysqld --defaults-extra-file=${myCnf} ${mysqldOptions}";
};
postStart = ''
${lib.optionalString (!hasNotify) ''
# 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 /tmp/mysql_init ]
then
${concatMapStrings (database:
''
# Create initial databases
if ! test -e "${cfg.dataDir}/${database.name}"; then
echo "Creating initial database: ${database.name}"
( echo 'create database `${database.name}`;'
${optionalString (database ? "schema") ''
echo 'use `${database.name}`;'
if [ -f "${database.schema}" ]
then
cat ${database.schema}
elif [ -d "${database.schema}" ]
then
cat ${database.schema}/mysql-databases/*.sql
fi
''}
) | ${mysql}/bin/mysql -u root -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}';"
) | ${mysql}/bin/mysql -u root -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;"
) | ${mysql}/bin/mysql -u root -N
''}
${optionalString (cfg.initialScript != null)
''
# Execute initial script
cat ${cfg.initialScript} | ${mysql}/bin/mysql -u root -N
''}
${optionalString (cfg.rootPassword != null)
''
# Change root password
( echo "use mysql;"
echo "update user set Password=password('$(cat ${cfg.rootPassword})') where User='root';"
echo "flush privileges;"
) | ${mysql}/bin/mysql -u root -N
''}
rm /tmp/mysql_init
fi
${optionalString (cfg.ensureDatabases != []) ''
(
${concatMapStrings (database: ''
echo "CREATE DATABASE IF NOT EXISTS ${database};"
'') cfg.ensureDatabases}
) | ${mysql}/bin/mysql -u root -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)}
) | ${mysql}/bin/mysql -u root -N
'') cfg.ensureUsers}
''; # */
};
};
}