0004 — PostGIS image for local development

Status: accepted Date: 2026-08-02

Context

§3 fixes the database as PostgreSQL 16 + PostGIS. The canonical image, postgis/postgis:16-3.5, publishes amd64 only:

no matching manifest for linux/arm64/v8 in the manifest list entries

Development happens on Apple Silicon. Running the amd64 image under emulation works but is slow enough to make integration tests unpleasant, and Testcontainers will pull the same image in every test run.

Decision

Use imresamu/postgis:16-3.5, the multi-arch build of the same Dockerfile maintained by a PostGIS Docker maintainer. It publishes amd64 and arm64, so one tag serves both local development and CI.

Verified: PostgreSQL 16.10, PostGIS 3.5.

Consequences

• The image is not under the postgis organisation. If that matters for supply chain policy, the alternative is ghcr.io/baosystems/postgis:16 (also multi-arch) or building from the official Dockerfile.
• The tag is pinned to a minor version, not latest.