feat: configure docker compose for self-hosting

[samyuktaap]

Description

This PR adds full Docker and Docker Compose configuration for the DevCard monorepo to enable simple self-hosting and local development setups. It also fixes an ES module resolution issue in the @devcard/shared package that was causing the backend to crash-loop under the Node.js production runtime.

Closes #37

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Proposed Changes

1. Dockerization

• Root Docker Compose Config (docker-compose.yml): Defines services for:
  • db (postgres:15-alpine): Persistent data volume, configuration credentials, and health check validation.
  • redis (redis:7-alpine): Cache layer with persistent storage and health checks.
  • backend (built from apps/backend/Dockerfile): Configured to depend on the healthy database and redis containers.
  • web (built from apps/web/Dockerfile): Serves the SvelteKit application and proxy-points to the backend container.
• Development Overrides (docker-compose.override.yml): Configures hot-reloading for local development by mounting the monorepo workspace into /app and specifying development entry points (pnpm dev).
• Optimized Docker Contexts (.dockerignore): Excludes heavy or runtime-specific folders (node_modules, .git, .gemini, .svelte-kit, build logs) to make container building lightweight and fast.

2. Multi-Stage Dockerfiles

• Backend (apps/backend/Dockerfile): Implements a multi-stage Node.js build:
  1. Installs monorepo dependencies.
  2. Runs Prisma client generation.
  3. Compiles the @devcard/shared library and typescript backend source code.
  4. Runs the production image by copying compiled bundles into a minimal runner container.
• Frontend (apps/web/Dockerfile): Configures SvelteKit build using adapter-node to run under the runtime server environment.

3. ESM Relative Import Fix (Blocker)

• File Modified: packages/shared/src/index.ts
• Issue: Under Node's Native ES Modules ("type": "module"), relative path imports must explicitly specify file extensions (e.g. .js) at runtime. Importing from ./platforms and ./types compiled literally without extensions, throwing a fatal ERR_MODULE_NOT_FOUND error inside the compiled backend build.
• Resolution: Appended explicit .js extensions (./platforms.js and ./types.js) to index relative exports so Node.js resolves them correctly at runtime.

4. Configuration & Documentation

• .env.example: Created at the repository root, detailing all database, redis, security tokens (JWT_SECRET, ENCRYPTION_KEY), app URLs, and server parameters.
• README.md: Updated with a Self-Hosting section detailing the step-by-step Compose workflow.

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Verification & Testing

1. Service Startup

Running docker compose up -d brings up all 4 containers successfully:

CONTAINER ID   IMAGE                COMMAND                  STATUS                    PORTS
84596cc14cf0   devcard-web          "docker-entrypoint.s…"   Up 7 seconds              0.0.0.0:5173->5173/tcp
dbff655fe8bc   devcard-backend      "docker-entrypoint.s…"   Up 8 seconds              0.0.0.0:3001->3001/tcp
c3d7a525fe14   postgres:15-alpine   "docker-entrypoint.s…"   Up 15 seconds (healthy)   0.0.0.0:5432->5432/tcp
b6599cd44323   redis:7-alpine       "docker-entrypoint.s…"   Up 15 seconds (healthy)   0.0.0.0:6379->6379/tcp

2. Backend Health Verification

Requesting http://localhost:3001/health confirms the NestJS/Fastify backend API is active and connected to PostgreSQL and Redis:

{
  "status": "ok",
  "timestamp": "2026-05-23T05:36:18.445Z",
  "service": "devcard-api"
}

3. Frontend Web Verification

Requesting http://localhost:5173/ returns 200 OK with successfully compiled SvelteKit bundle scripts and stylesheet links.

[Harxhit]

@samyuktaap Please give us some time to review PR.

[ShantKhatri]

Why do we need to make changes in the dev files while configuring Docker Compose here?

[samyuktaap]

Hi @ShantKhatri,

Great question! While these look like changes to development/source files, they were actually necessary to resolve TypeScript compile-time errors and production runtime crashes that occur when compiling and running the application inside a production Docker container.

Here is a breakdown of why each change was needed:

1. Swapping to adapter-node (apps/web/package.json & svelte.config.js)

• Problem: By default, SvelteKit uses @sveltejs/adapter-auto which targets serverless platforms (Vercel, Netlify, etc.). This doesn't produce a standalone server package.
• Solution: We changed it to @sveltejs/adapter-node so that SvelteKit compiles into a standalone Node.js server that can run directly inside the Docker container (node build/index.js).

2. Standardizing ES Modules imports/exports (packages/shared/src/index.ts & package.json)

• Problem:
  1. The project uses ES Modules ("type": "module"). At runtime, Node's ESM loader strictly requires relative imports to specify file extensions (e.g. ./types.js instead of extensionless ./types). The extensionless imports caused the backend container to crash immediately with ERR_MODULE_NOT_FOUND.
  2. The shared package originally pointed its main entry directly to the TypeScript file (./src/index.ts). While dev tools like Vite and tsx can resolve this dynamically in development, Node.js cannot run TypeScript files directly in production.
• Solution: We added explicit .js extensions to the exports in the shared package and updated its entry point to point to the compiled ./dist/index.js output.

3. Fixing the Encryption imports (apps/backend/src/routes/auth.ts & connect.ts)

• Problem: These files were calling (app as any).encryption.encrypt(). However, no encryption plugin is actually registered on the Fastify instance in app.ts. Inside the container, this resulted in runtime crashes or unencrypted tokens.
• Solution: We replaced it with the existing encrypt helper imported directly from ../utils/encryption.js to ensure tokens are securely encrypted without crashing the server.

4. Resolving TypeScript compilation errors (apps/backend/src/app.ts & tsconfig.json)

• Problem: When building the production Docker image, we run tsc to compile the backend. The compilation failed because FastifyInstance doesn't natively have the custom authenticate property (it is registered dynamically at runtime).
• Solution: We added a TypeScript module declaration in app.ts to declare authenticate on FastifyInstance and excluded test directories from compilation in tsconfig.json, allowing the build to pass successfully.