build: support regional dependency mirrors

docker/.env.production.example

@@ -1,6 +1,11 @@
 # Image tag built by docker/docker-compose.prod.yml
 IMAGEFORGE_TAG=local
 
+# Optional regional mirror used only while building Debian image layers.
+DEBIAN_MIRROR=http://deb.debian.org/debian
+# Optional sparse Cargo registry mirror used only while building the API image.
+CARGO_REGISTRY_MIRROR=
+
 # Public listener and URL
 IMAGEFORGE_BIND_ADDRESS=0.0.0.0
 IMAGEFORGE_PORT=8080

docker/Dockerfile

@@ -2,9 +2,14 @@
 
 FROM rust:1.92-trixie AS builder
 
+ARG DEBIAN_MIRROR=http://deb.debian.org/debian
+ARG CARGO_REGISTRY_MIRROR=
+
 WORKDIR /app
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
+RUN sed -i "s|http://deb.debian.org/debian|${DEBIAN_MIRROR%/}|g" /etc/apt/sources.list.d/debian.sources \
+  && DEBIAN_FRONTEND=noninteractive apt-get update \
+  && apt-get install -y --no-install-recommends \
     cmake \
     libdav1d-dev \
     nasm \
@@ -12,13 +17,18 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   && rm -rf /var/lib/apt/lists/*
 
 COPY Cargo.toml Cargo.lock ./
+COPY .cargo ./.cargo
 COPY src ./src
 COPY migrations ./migrations
 COPY templates ./templates
 
 RUN --mount=type=cache,target=/usr/local/cargo/registry,sharing=locked \
     --mount=type=cache,target=/app/target,sharing=locked \
-    cargo build --release --locked \
+    if [ -n "$CARGO_REGISTRY_MIRROR" ]; then \
+      printf '\n[source.crates-io]\nreplace-with = "deployment-mirror"\n\n[source.deployment-mirror]\nregistry = "%s"\n' \
+        "$CARGO_REGISTRY_MIRROR" >> .cargo/config.toml; \
+    fi \
+  && cargo build --release --locked \
   && cp /app/target/release/imageforge /app/imageforge
 
 FROM node:22-alpine AS frontend-builder
@@ -31,7 +41,11 @@ RUN npm run build
 
 FROM debian:trixie-slim
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
+ARG DEBIAN_MIRROR=http://deb.debian.org/debian
+
+RUN sed -i "s|http://deb.debian.org/debian|${DEBIAN_MIRROR%/}|g" /etc/apt/sources.list.d/debian.sources \
+  && DEBIAN_FRONTEND=noninteractive apt-get update \
+  && apt-get install -y --no-install-recommends \
     ca-certificates \
     curl \
     libdav1d7 \

docker/docker-compose.prod.yml

@@ -55,6 +55,9 @@ services:
     build:
       context: ..
       dockerfile: docker/Dockerfile
+      args:
+        DEBIAN_MIRROR: ${DEBIAN_MIRROR:-http://deb.debian.org/debian}
+        CARGO_REGISTRY_MIRROR: ${CARGO_REGISTRY_MIRROR:-}
     init: true
     environment:
       <<: *imageforge-environment