# Base image (/docs/template/base-image)
Related: [Quickstart](/docs/template/quickstart.md), [How it works](/docs/template/how-it-works.md), [User and workdir](/docs/template/user-and-workdir.md), [Caching](/docs/template/caching.md), [Private registries](/docs/template/private-registries.md), [Defining template](/docs/template/defining-template.md)
## Creating template [#creating-template]
When creating a template, you can specify options:
JavaScript & TypeScript
Python
```typescript
const template = Template({
fileContextPath: ".", // Custom file context path
fileIgnorePatterns: [".git", "node_modules"], // File patterns to ignore
});
```
```python
template = Template(
file_context_path=".", # Custom file context path
file_ignore_patterns=[".git", "node_modules"], # File patterns to ignore
)
```
**File ignoring**: The SDK automatically reads `.dockerignore` files and combines them with your `fileIgnorePatterns` (TypeScript) or `file_ignore_patterns` (Python). Files matching these patterns are excluded from uploads and hash calculations.
## Defining base image [#defining-base-image]
Every template starts with a base image that provides the foundation for your sandbox environment.
E2B currently supports only Debian-based images. Your base image must be Debian or a Debian derivative (e.g., `debian`, `ubuntu`, `python`, `node`). Alpine, RedHat-based, and other non-Debian distributions are not supported.
### Predefined base images [#predefined-base-images]
Use convenience methods for common base images with Ubuntu, Debian, Python, Node.js, or Bun:
JavaScript & TypeScript
Python
```typescript
template.fromUbuntuImage("22.04"); // ubuntu:22.04
template.fromDebianImage("stable-slim"); // debian:stable-slim
template.fromPythonImage("3.13"); // python:3.13
template.fromNodeImage("lts"); // node:lts
template.fromBunImage("1.3"); // oven/bun:1.3
```
```python
template.from_ubuntu_image("22.04") # ubuntu:22.04
template.from_debian_image("stable-slim") # debian:stable-slim
template.from_python_image("3.13") # python:3.13
template.from_node_image("lts") # node:lts
template.from_bun_image("1.3") # oven/bun:1.3
```
### Custom base image [#custom-base-image]
Use any Docker image from Docker Hub or other registries:
JavaScript & TypeScript
Python
```typescript
template.fromImage("custom-image:latest");
```
```python
template.from_image("custom-image:latest")
```
### Default E2B base image [#default-e2b-base-image]
Use the default E2B base image, which comes pre-configured for sandbox environments:
JavaScript & TypeScript
Python
```typescript
template.fromBaseImage(); // e2bdev/base
```
```python
template.from_base_image() # e2bdev/base
```
`base` is also the template used when you call `Sandbox.create()` without specifying one. It is Debian-based and comes with common tooling pre-installed: Python 3, Node.js, Yarn, `git`, `curl`, `build-essential`, and the GitHub CLI (`gh`). For the exact contents, see the public Dockerfile: [`templates/base/e2b.Dockerfile`](https://github.com/e2b-dev/E2B/blob/main/templates/base/e2b.Dockerfile).
### Default resources [#default-resources]
A sandbox gets its CPU and memory from the template it's built on. A sandbox built from `base` starts with **2 vCPU and 512 MiB of RAM**.
You can override CPU and memory when you [build a template](/docs/template/build) (`cpuCount`/`cpu_count`, `memoryMB`/`memory_mb`). Disk size is not a default you set per sandbox; it's determined by your project's tier limit and applied at build time (see [Build limits](/docs/template/quickstart#build-limits)).
### Build from existing template [#build-from-existing-template]
Extend an existing template from your project or organization:
JavaScript & TypeScript
Python
```typescript
template.fromTemplate("my-template"); // Your project's template
template.fromTemplate("acme/other-template"); // Full namespaced reference
```
```python
template.from_template("my-template") # Your project's template
template.from_template("acme/other-template") # Full namespaced reference
```
You can only call base image methods once per template. Subsequent calls will throw an error.
## Parsing existing Dockerfiles [#parsing-existing-dockerfiles]
Convert existing Dockerfiles to template format using `fromDockerfile()`:
JavaScript & TypeScript
Python
```typescript
const dockerfileContent = `
FROM ubuntu:22.04
RUN apt-get update && apt-get install -y curl
WORKDIR /app
COPY . .
ENV NODE_ENV=production
ENV PORT=3000
USER appuser`;
const template = Template()
.fromDockerfile(dockerfileContent)
.setStartCmd("npm start", waitForTimeout(5_000));
```
```python
dockerfile_content = """
FROM ubuntu:22.04
RUN apt-get update && apt-get install -y curl
WORKDIR /app
COPY . .
ENV NODE_ENV=production
ENV PORT=3000
USER appuser
"""
template = (
Template()
.from_dockerfile(dockerfile_content)
.set_start_cmd("npm start", wait_for_timeout(5_000))
)
```
### Dockerfile instructions support [#dockerfile-instructions-support]
| Instruction | Supported | Behavior |
| :------------------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------: | :------------------------------------------------------------------------------------------------ |
| `FROM` | | Sets base image |
| `RUN` | | Converts to `runCmd()` / `run_cmd()` |
| `COPY` / `ADD` | | Converts to `copy()` |
| `WORKDIR` | | Converts to `setWorkdir()` / `set_workdir()` |
| `USER` | | Converts to `setUser()` / `set_user()` |
| `ENV` | | Converts to `setEnvs()` / `set_envs()`; supports both `ENV key=value` and `ENV key value` formats |
| `CMD` / `ENTRYPOINT` | | Converts to `setStartCmd()` / `set_start_cmd()` with 20 seconds timeout as ready command |
| `EXPOSE` | | Skipped (not supported) |
| `VOLUME` | | Skipped (not supported) |
Multi-stage Dockerfiles are not supported.