🧩 Adding Starter Templates to Devex

📄 Before You Begin Make sure to read the Contribution Guide at the root of the repo before proceeding.

🚀 Steps to Add a New Template

✅ Step 1: Add Template Folder in templates/

• •
  Create a new folder inside templates/.
• •
  This folder name will act as the template key and must:
  • •Be unique.
  • •Be URL-friendly (use - instead of spaces).
  • •Match exactly across all usages (templates, runner, web, core).
  • •Be below 8MB in size.

Example: For a template named node, create templates/node/.

⚙️ Step 2: Add a Dockerfile in runner/

• •Create a Dockerfile in runner/ named <template-key>.dockerfile.

Example: For a node template: Create runner/node.dockerfile

🔧 Sample Dockerfile

Dockerfile
# ---- Step 1: Build Stage ----
FROM golang:1.24 AS builder
WORKDIR /app

COPY go.mod go.sum ./
RUN go mod tidy

COPY . .
RUN CGO_ENABLED=0 GOOS=linux go build -o runner ./cmd/main.go

# ---- Step 2: Final Runtime Stage ----
FROM node:20-slim
WORKDIR /app

RUN apt-get update && \
    apt-get install -y --no-install-recommends \
    bash \
    curl \
    ca-certificates && \
    rm -rf /var/lib/apt/lists/*

RUN npm install -g nodemon typescript ts-node

RUN curl -sS https://starship.rs/install.sh | sh -s -- -y && \
    echo 'eval "$(starship init bash)"' >> /root/.bashrc

COPY --from=builder /app/runner .

EXPOSE 8080
CMD ["/app/runner"]

🚫 Note: Do not modify the Go runner source code.

💡 Add any static files needed by your template inside templates/<template-key>/.

🧠 Step 3: Register the Template in the Web UI

tsx
node: {
  key: "node",
  name: "Node.js",
  description: "JavaScript runtime environment",
  icon: (
    <IconBrandNodejs className="bg-green-800 h-9 w-9 p-2 rounded-full" />
  ),
},

🧩 The key must match the template folder and Dockerfile name exactly.

🛡 Step 4: Add Template to Whitelist in Backend

go
"node": {
	BaseImage: "node:20-slim",
	Port:      8081,
},

🔐 This step ensures only validated templates are accepted by the backend.

📝 Final Notes

• •Do not change the core Go runner logic.
• •Keep Dockerfiles lean and efficient.
• •Use only required dependencies in each template.
• •Avoid hardcoding secrets or large assets directly in the template.

📦 Example Template Keys

🙌 Contributing