Add support to build MCP Gateway for s390x platform

Containerfile

@@ -5,24 +5,39 @@ LABEL maintainer="Mihai Criveti" \
       description="MCP Gateway: An enterprise-ready Model Context Protocol Gateway"
 
 ARG PYTHON_VERSION=3.12
+ARG TARGETPLATFORM
+ARG GRPC_PYTHON_BUILD_SYSTEM_OPENSSL='False'
 
 # Install Python and build dependencies
 # hadolint ignore=DL3041
 RUN microdnf update -y && \
-    microdnf install -y python${PYTHON_VERSION} python${PYTHON_VERSION}-devel gcc git && \
+    microdnf install -y python${PYTHON_VERSION} python${PYTHON_VERSION}-devel gcc git openssl-devel postgresql-devel gcc-c++ && \
     microdnf clean all
 
 # Set default python3 to the specified version
 RUN update-alternatives --install /usr/bin/python3 python3 /usr/bin/python${PYTHON_VERSION} 1
 
 WORKDIR /app
 
+# ----------------------------------------------------------------------------
+# s390x architecture does not support BoringSSL when building wheel grpcio.
+# Force Python whl to use OpenSSL.
+# ----------------------------------------------------------------------------
+RUN if [ "$TARGETPLATFORM" = "linux/s390x" ]; then \
+        echo "Building for s390x."; \
+        echo "export GRPC_PYTHON_BUILD_SYSTEM_OPENSSL='True'" > /etc/profile.d/use-openssl.sh; \
+    else \
+        echo "export GRPC_PYTHON_BUILD_SYSTEM_OPENSSL='False'" > /etc/profile.d/use-openssl.sh; \
+    fi
+RUN chmod 644 /etc/profile.d/use-openssl.sh
+
 # Copy project files into container
 COPY . /app
 
 # Create virtual environment, upgrade pip and install dependencies using uv for speed
 # Including observability packages for OpenTelemetry support
 RUN python3 -m venv /app/.venv && \
+    . /etc/profile.d/use-openssl.sh && \
     /app/.venv/bin/python3 -m pip install --upgrade pip setuptools pdm uv && \
     /app/.venv/bin/python3 -m uv pip install ".[redis,postgres,mysql,alembic,observability]"
 

Containerfile.lite

@@ -31,6 +31,8 @@ SHELL ["/bin/bash", "-euo", "pipefail", "-c"]
 
 ARG PYTHON_VERSION
 ARG ROOTFS_PATH
+ARG TARGETPLATFORM
+ARG GRPC_PYTHON_BUILD_SYSTEM_OPENSSL='False'
 
 # ----------------------------------------------------------------------------
 # 1) Patch the OS
@@ -45,12 +47,24 @@ RUN set -euo pipefail \
     && dnf install -y \
          python${PYTHON_VERSION} \
          python${PYTHON_VERSION}-devel \
-         binutils \
+         binutils openssl-devel gcc postgresql-devel gcc-c++ \
     && update-alternatives --install /usr/bin/python3 python3 /usr/bin/python${PYTHON_VERSION} 1 \
     && dnf clean all
 
 WORKDIR /app
 
+# ----------------------------------------------------------------------------
+# s390x architecture does not support BoringSSL when building wheel grpcio.
+# Force Python whl to use OpenSSL.
+# ----------------------------------------------------------------------------
+RUN if [ "$TARGETPLATFORM" = "linux/s390x" ]; then \
+        echo "Building for s390x."; \
+        echo "export GRPC_PYTHON_BUILD_SYSTEM_OPENSSL='True'" > /etc/profile.d/use-openssl.sh; \
+    else \
+        echo "export GRPC_PYTHON_BUILD_SYSTEM_OPENSSL='False'" > /etc/profile.d/use-openssl.sh; \
+    fi
+RUN chmod 644 /etc/profile.d/use-openssl.sh
+
 # ----------------------------------------------------------------------------
 # Copy only the files needed for dependency installation first
 # This maximizes Docker layer caching - dependencies change less often
@@ -66,6 +80,7 @@ COPY pyproject.toml /app/
 #  - Remove build caches and build artifacts
 # ----------------------------------------------------------------------------
 RUN set -euo pipefail \
+    && . /etc/profile.d/use-openssl.sh \
     && python3 -m venv /app/.venv \
     && /app/.venv/bin/pip install --no-cache-dir --upgrade pip setuptools wheel pdm uv \
     && /app/.venv/bin/uv pip install ".[redis,postgres,mysql,observability]" \

Makefile

@@ -1821,7 +1821,7 @@ endif
 # =============================================================================
 
 # Auto-detect container runtime if not specified - DEFAULT TO DOCKER
-CONTAINER_RUNTIME ?= $(shell command -v docker >/dev/null 2>&1 && echo docker || echo podman)
+CONTAINER_RUNTIME = $(shell command -v docker >/dev/null 2>&1 && echo docker || echo podman)
 
 # Alternative: Always default to docker unless explicitly overridden
 # CONTAINER_RUNTIME ?= docker
@@ -2105,14 +2105,14 @@ container-build-multi:
 		fi; \
 		docker buildx use $(PROJECT_NAME)-builder; \
 		docker buildx build \
-			--platform=linux/amd64,linux/arm64 \
+			--platform=linux/amd64,linux/arm64,linux/s390x \
 			-f $(CONTAINER_FILE) \
 			--tag $(IMAGE_BASE):$(IMAGE_TAG) \
 			--push \
 			.; \
 	elif [ "$(CONTAINER_RUNTIME)" = "podman" ]; then \
 		echo "📦 Building manifest with Podman..."; \
-		$(CONTAINER_RUNTIME) build --platform=linux/amd64,linux/arm64 \
+		$(CONTAINER_RUNTIME) build --platform=linux/amd64,linux/arm64,linux/s390x \
 			-f $(CONTAINER_FILE) \
 			--manifest $(IMAGE_BASE):$(IMAGE_TAG) \
 			.; \