Railway.MySQL reference

ConnectMySQL

Source: src/Railway/ConnectMySQL.ts

Bind a MySQL service to a Railway Service and obtain the Effect-native connection string for Drizzle.MySQL / SQL.MySQL.

ConnectMySQL is the Context tag, the type, and the callable — yield* Railway.ConnectMySQL(Db). Provide ConnectMySQLHttp.

ConnectMySQL: Examples

import * as Drizzle from "alchemy/Drizzle/MySQL";

const conn = yield* Railway.ConnectMySQL(Db);
const db = yield* Drizzle.MySQL(conn.connectionString);

fetch: Effect.gen(function* () {
  const rows = yield* db.execute("select 1 as ok", "objects");
});

ConnectMySQL: Variable references

ConnectMySQL packs a typed private URI onto the Service. To store Railway’s template instead of a resolved URI (IaC db.env.MYSQL_URL), pass Railway.ref(Db, "MYSQL_URL") as a Variable value or Service.env entry.

const db = yield* Railway.MySQL("Db", { project: site });
yield* Railway.Variable("MysqlUrl", {
  project: site,
  service: api,
  name: "MYSQL_URL",
  value: Railway.ref(db, "MYSQL_URL"),
});

ConnectMySQLHttp

Source: src/Railway/ConnectMySQLHttp.ts Kind: Layer · Provides: Railway.ConnectMySQL

Implementation of ConnectMySQL. Provide it on the Service Effect.

At deploy time this packs the private connection URI onto the host (RAILWAY_MYSQL_*, MYSQL_URL). At runtime the client reads process.env.

ConnectMySQLHttp: Provide the layer

Effect.gen(function* () {
  const conn = yield* Railway.ConnectMySQL(Db);
  const db = yield* Drizzle.MySQL(conn.connectionString);
}).pipe(Effect.provide(Railway.ConnectMySQLHttp))

MySQL

Source: src/Railway/MySQL.ts

A Railway.MySQL is a MySQL-as-a-Service: the official mysql image, a Volume at /var/lib/mysql, MYSQL_* / MYSQL_URL variables, and an optional TCP proxy for the public URL. This is Alchemy’s mysql() helper (Railway IaC: mysql("mysql")).

Private hostname is {name}.railway.internal. From a Service, yield ConnectMySQL. From a laptop, use publicConnectionUri.

MySQL: Create MySQL

Pass a Project. Alchemy generates a unique name, password, volume, and a public TCP proxy.

const site = yield* Railway.Project("Site");
const db = yield* Railway.MySQL("Db", { project: site });

Changing project replaces MySQL

A new service + volume are created in the new Project. The old service and volume are deleted. Data is not copied.

MySQL: Connect from a Service

Yield ConnectMySQL inside init. Provide ConnectMySQLHttp. Pass conn.connectionString to Drizzle.MySQL or SQL.MySQL. The binding packs the private URI ({name}.railway.internal).

import * as Drizzle from "alchemy/Drizzle/MySQL";
import * as HttpServerResponse from "effect/unstable/http/HttpServerResponse";

export default class Api extends Railway.Service<Api>()(
  "Api",
  { project: Site, main: import.meta.url, build: { install: ["mysql2"] } },
  Effect.gen(function* () {
    const conn = yield* Railway.ConnectMySQL(Db);
    const db = yield* Drizzle.MySQL(conn.connectionString);
    return {
      fetch: Effect.gen(function* () {
        const rows = yield* db.execute("select 1 as ok", "objects");
        return HttpServerResponse.json({ rows });
      }),
    };
  }).pipe(Effect.provide(Railway.ConnectMySQLHttp)),
) {}

MySQL: Public TCP

public (default true) creates a TCP proxy on 3306. publicConnectionUri is {domain}:{proxyPort} for laptop access and deploy-time migrations.

const db = yield* Railway.MySQL("Db", {
  project: site,
  public: false,
});

MySQL: Image

Default is official MySQL 9. Pass image to pin another tag.

const db = yield* Railway.MySQL("Db", {
  project: site,
  image: "mysql:8",
});

MySQL: Module-scope declarations

Resource-valued props accept the resource or an Effect producing it.

src/db.ts

import * as Railway from "alchemy/Railway";

export const Site = Railway.Project("Site");
export const Db = Railway.MySQL("Db", { project: Site });