object client.md
Configure S3-compatible access for Gin
Summary
Object storage client for a Gin app on Ample. Verified on Gin: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=ok). Build and start: CGO_ENABLED=0 go build -o app ./... then ./app on the ubuntu-24.04 template (go.sum committed for a reproducible build).
Infrastructure requirements
- Compute: verified (Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.)
- S3-compatible object storage: verified (Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.)
Prerequisites
- A Gin project (CGO_ENABLED=0 go build -o app ./... then ./app on the ubuntu-24.04 template (go.sum committed for a reproducible build))
- A bucket from
ample bucket createwith credentials passed as encrypted S3_* environment variables - An Ample account token with servers:write, buckets:read
Exact tested configuration
- template:
ubuntu-24.04 - runtime:
go - size:
s-1vcpu-1gb - build:
CGO_ENABLED=0 go build -o app ./... - start:
./app
Steps
- Build and start. CGO_ENABLED=0 go build -o app ./... then ./app on the ubuntu-24.04 template (go.sum committed for a reproducible build); the server must bind 0.0.0.0 on PORT.
- Create the bucket and pass its credentials. Create it once with
ample bucket create, then pass endpoint, region, bucket and keys with --env; use path-style addressing.
ample deploy . --name <app-name> --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...
- Verify. Fetch the live URL and /p/browser-file-uploads on the example; on failure read the build and runtime logs.
ample logs <deployment_id> --kind build
Tested examples
- Gin pattern fixture (tests/deploy-canaries/gin-patterns): Verified object storage client on Gin.
Success checks
- app responds on its public URL (
/on the live URL, expect ample canary gin patterns) - browser-file-uploads check from the example (
/p/browser-file-uploadson the live URL, expect see the pattern fixture checks)
Limitations
- Verified on the ubuntu-24.04 template at s-1vcpu-1gb; other sizes and Gin major versions are not verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- PutObject and GetObject with path-style addressing are verified; other S3 operations are not.
Cost estimate
Estimated 5.00 USD per month (size prices from pricing.toml at build revision a1b8c38919e59cd035ebabaced73cf84ece24371).
- app server x1
s-1vcpu-1gb: 5.00 USD
Always-on monthly price of the tested sizes; apps auto-pause when idle. Buckets are allocation-priced per quota and not included.
Verification evidence
- canary_run on 2026-09-21T01:15:54Z at revision
50dbac567d2c5cc8e55e6c748a646be0025d9cfb-dirty (CLI 0.1.21): Gin pattern fixture deployed on Ample (CGO_ENABLED=0 go build -o app ./... then ./app on the ubuntu-24.04 template (go.sum committed for a reproducible build)); for this guide: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=ok). (expires 2027-03-20T01:15:54Z)
Last verified: 2026-09-21T01:15:54Z
Execution binding
MCP tool ample_deploy (registry mcp:ample_deploy), schema hash 876465fce906da0c observed 2026-09-21T03:19:59.461917+00:00 at revision 49962bcade4f, binding state current, required scopes: servers:write, buckets:read.