add relay server to development network

crates/gsio-relay/Dockerfile

@@ -0,0 +1,33 @@
+################################################################
+#  Stage 1 – build rustls-cert-gen and generate the certs
+################################################################
+FROM rust:bookworm AS ssl-step
+
+# ↓ Allow override of SAN / output directory at build time
+ARG CERT_DOMAIN=relay.local
+ARG OUT_DIR=/app/ssl
+
+# ── deps we need only for the build ───────────────────────────
+RUN apt-get update -qq && \
+    apt-get install -y --no-install-recommends git ca-certificates && \
+    rm -rf /var/lib/apt/lists/*
+
+# ── fetch the rcgen repo (contains the CLI) and build once ────
+WORKDIR /src
+RUN git clone --depth 1 https://github.com/rustls/rcgen.git
+WORKDIR /src/rcgen
+RUN cargo run -- -o /app/ssl
+
+################################################################
+#  Stage 2 – minimal runtime with the iroh relay
+################################################################
+FROM n0computer/iroh-relay:v0.28.2
+
+# copy the certs produced in stage 1
+COPY --from=ssl-step /app/ssl /app/ssl
+
+# your relay configuration
+COPY ./relay-config.toml /app/
+
+# hand off control to the relay
+CMD ["--dev"]