Choosing a Runtime Base on Zerops

Keywords

alpine, ubuntu, docker, container, base image, linux, runtime base, os, choose base, which container

TL;DR

Use Alpine as the default base for all services. Use Ubuntu only when you need system packages not available in Alpine. Use Docker only for pre-built images.

Decision Matrix

Need	Choice	Why
Any standard app	Alpine (default)	~5MB, fast, secure, sufficient for 95% of apps
System packages (apt)	Ubuntu	Full Debian ecosystem, ~100MB
Pre-built Docker images	Docker	VM-based, bring your own image
CGO / native libs	Ubuntu	Better glibc compatibility than Alpine's musl

Alpine (Default)

• Size: ~5MB base
• Package manager: apk add
• Best for: All runtimes (Node.js, Python, Go, Rust, Java, PHP, etc.)
• Zerops uses Alpine as default base for all managed runtimes

Ubuntu

• Size: ~100MB base
• Package manager: apt-get install
• Version: 24.04 LTS
• Use when: You need packages not available in Alpine, or need glibc (not musl)
• Example: Go apps with CGO, Python packages with C extensions that don't compile on musl

Docker

• Runs in a VM (not a container) — slower boot, higher overhead
• Network: Must use --network=host or network_mode: host in compose
• Scaling: Fixed resources only (no min-max auto-scaling), VM restarts on resource change
• Disk: Can only increase, never decrease without recreation
• Build phase runs in containers (not VMs)
• Always use specific version tags — :latest is cached and won't re-pull

Gotchas

1. Alpine uses musl: Some C libraries may not compile — use Ubuntu if you hit musl issues
2. Docker is VM-based: Vertical scaling restarts the VM — expect brief downtime
3. Docker :latest is cached: Zerops won't re-pull — always use specific tags like myapp:1.2.3
4. Docker requires host networking: Without --network=host, the container can't receive traffic

See Also

• zerops://runtimes/{name} — per-runtime guides (e.g. zerops://runtimes/alpine, zerops://runtimes/docker)
• zerops://themes/core — build environment rules