nix/shared/db/postgres.nix
2025-08-02 01:05:50 +02:00

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3.1 KiB
Nix

{ config, pkgs, lib, ... }:
let
# Import nodes
nodes = import ./../../nodes.nix;
myName = config.hostName;
myNode = nodes."${myName}";
# And mapping
mapping = import ./../../mapping.nix;
cfg = config.services.postgresql;
masterNode = nodes.${mapping.db.master};
masterIP = "172.19.${toString masterNode.zone}.${toString masterNode.id}";
in
{
age.secrets."repli" = {
file = ./../../secrets/db/repli.age;
owner = "postgres";
group = "postgres";
};
systemd.services.postgresql.environment = lib.mkIf (builtins.elem myName mapping.db.slaves) {
PGPASSFILE = "${config.age.secrets.repli.path}";
};
services.postgresql = {
enable = true;
# Force postgres package major version
# to avoid any unwanted upgrades
package = pkgs.postgresql_17;
identMap = ''
# ArbitraryMapName systemUser DBUser
superuser_map root postgres
superuser_map postgres postgres
'';
authentication = lib.mkOverride 10 (builtins.concatStringsSep "\n " ([''
#type database DBuser auth-method optional_ident_map
local all all peer map=superuser_map
'']
++ lib.optionals (myName == mapping.db.master)
(map (slaveName: let slaveNode = nodes.${slaveName}; in
"host replication replication 172.19.${toString slaveNode.zone}.${toString slaveNode.id}/32 md5"
) mapping.db.slaves)
++ lib.optionals (builtins.elem myName mapping.db.slaves) [''
host replication replication ${masterIP}/32 md5
'']));
ensureUsers = [{
name = "replication";
ensureClauses.replication = true;
}];
settings = {
listen_addresses = lib.mkForce "localhost,172.19.${toString myNode.zone}.${toString myNode.id}";
port = 5432;
log_connections = true;
log_statement = "none";
logging_collector = true;
log_disconnections = true;
} // lib.optionalAttrs (myName == mapping.db.master) {
wal_level = "logical";
wal_sender_timeout = 10;
max_wal_senders = 16;
wal_keep_size = 1000; # In MB
} // lib.optionalAttrs (builtins.elem myName mapping.db.slaves) {
wal_level = "logical";
wal_receiver_timeout = 10;
primary_conninfo = "host=${masterIP} port=5432 user=replication";
hot_standby = "on";
};
};
# The password looks like: "*:*:*:*:<password>"
# Cf: https://www.postgresql.org/docs/current/libpq-pgpass.html
systemd.services.postgresql.postStart = lib.mkIf (myName == mapping.db.master) ''
$PSQL -tA <<'EOF'
DO $$
DECLARE password TEXT;
BEGIN
password := trim(both from split_part(replace(pg_read_file('${config.age.secrets.repli.path}'), E'\n', '''), ':', 5));
EXECUTE format('ALTER USER replication WITH PASSWORD '''%s''';', password);
END $$;
EOF
'';
}