page:recipes:mobile backend:axum:artifact storage

Host mobile backend with Axum: stored input and output artifacts

Summary

Deploy a mobile backend built with Axum on Ample using the generated downloads pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL, a private S3-compatible bucket holds objects with credentials delivered as encrypted environment variables. Verified on Axum: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Not separately tested: your export formats, retention policy and entitlement model; treat the mobile backend-specific behavior as your application code.

Representative Queries

• Host mobile backend with Axum: stored input and output artifacts
• Where can I host Mobile backend built with Axum?
• I need an input/output artifact contract, object metadata and access boundaries.

Resource Requirements

• Compute
• Postgres
• S3-compatible object storage

Infrastructure Requirements

• Compute: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request.
• Postgres: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.
• S3-compatible object storage: Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary.

Prerequisites

• An Axum project that builds and starts with the documented commands (cargo build --release in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the ubuntu-24.04 template reading PORT and DATABASE_URL).
• A PostgreSQL driver reading DATABASE_URL at runtime.
• A bucket from ample bucket create with its credentials passed as encrypted S3_* environment variables.
• An Ample account token with servers:write, databases:read, buckets:read.

Workflow Steps

1. Build and start: cargo build --release in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the ubuntu-24.04 template reading PORT and DATABASE_URL. The server must bind 0.0.0.0 on PORT.
2. Implement the pattern on PostgreSQL: The fixture's module implements generated downloads: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller.
3. Wire object storage: Create the bucket(s) and pass endpoint, region, bucket and keys as --env values.
4. Deploy: Run the synchronous deploy once and read the result.
5. Verify: Fetch the live URL and the pattern self-test route(s) from the example; then run your own checks.

Success Checks

• App responds on its public URL.
• Generated-downloads self-test.

Limitations

• Verified on the ubuntu-24.04 template with the example fixture.
• The mobile backend itself has not been separately tested; the pattern checks are what was verified.

Cost Estimate

• Monthly Amount: $10.00
• Components:
  • App Server: $5.00
  • Managed PostgreSQL Database: $5.00

Examples

• Axum pattern fixture: Multi-pattern Axum app whose generated downloads module was checked live.

Next Actions

• Browse the catalog index.
• Search published recipes by intent, stack and constraints.
• Prepare a side-effect-free deployment plan for an authorized project.