Lpcox/slim serena image (#544)

Author: lpcox

.gitignore

@@ -54,3 +54,6 @@ test/serena-mcp-tests/results-gateway/
 test/serena-mcp-tests/**/__pycache__/
 test/serena-mcp-tests/**/*.pyc
 scripts/rebase-github-difc.sh
+
+# Serena cache directories
+.serena/

containers/serena-mcp-server/Dockerfile

@@ -1,11 +1,17 @@
-# Serena MCP Server Container Image
-# Provides AI-powered code intelligence with support for Python, Java, JavaScript/TypeScript, and Go
+# Serena MCP Server Container Image (Slim)
+# Optimized for Python, Go, and TypeScript support with minimal image size
 
+# Stage 1: Build gopls
+FROM golang:1.24-alpine AS gopls-builder
+# Pin to gopls v0.17.1 which is compatible with Go 1.24
+RUN go install golang.org/x/tools/gopls@v0.17.1
+
+# Stage 2: Final image
 FROM python:3.11-slim
 
 # OCI labels for GitHub Container Registry
 LABEL org.opencontainers.image.title="Serena MCP Server"
-LABEL org.opencontainers.image.description="A containerized MCP server with semantic code analysis for Python, Java, JavaScript/TypeScript, and Go"
+LABEL org.opencontainers.image.description="A containerized MCP server with semantic code analysis for Python, Go, and TypeScript"
 LABEL org.opencontainers.image.source="https://github.com/githubnext/gh-aw-mcpg/tree/main/containers/serena-mcp-server"
 LABEL org.opencontainers.image.documentation="https://github.com/githubnext/gh-aw-mcpg/blob/main/containers/serena-mcp-server/README.md"
 LABEL org.opencontainers.image.url="https://github.com/githubnext/gh-aw-mcpg/pkgs/container/serena-mcp-server"
@@ -14,53 +20,29 @@ LABEL org.opencontainers.image.vendor="GitHub"
 # Set working directory
 WORKDIR /app
 
-# Install system dependencies required for language servers and build tools
+# Install minimal system dependencies
+# - git: required for some Serena operations
+# - nodejs/npm: for TypeScript language server
+# - ca-certificates: for HTTPS
 RUN apt-get update && apt-get install -y --no-install-recommends \
-    # Build essentials
-    build-essential \
     git \
-    curl \
-    wget \
-    # Java Development Kit (for Java language support and compilation)
-    default-jdk \
-    # Node.js (for JavaScript/TypeScript language support)
     nodejs \
     npm \
-    # Go runtime (for Go language support)
-    golang-go \
-    # Additional utilities
     ca-certificates \
     && rm -rf /var/lib/apt/lists/* \
-    && update-ca-certificates
+    && apt-get clean
 
-# Set environment variables for language runtimes
-ENV JAVA_HOME=/usr/lib/jvm/default-java
-ENV PATH="${JAVA_HOME}/bin:${PATH}"
-ENV GOPATH=/go
-ENV PATH="${GOPATH}/bin:${PATH}"
+# Copy pre-built gopls from builder stage
+COPY --from=gopls-builder /go/bin/gopls /usr/local/bin/gopls
 
-# Install Serena MCP server from GitHub using pip
-# Serena is a Python package, so we can install it directly
-# Try GitHub first, then fall back to PyPI package name if available
+# Install Serena MCP server from GitHub
 RUN pip install --no-cache-dir git+https://github.com/oraios/serena.git || \
     (echo "GitHub installation failed, trying PyPI..." && \
      pip install --no-cache-dir serena-agent)
 
-# Install common language servers that Serena may need
-# These are installed globally to be available to Serena
-RUN npm install -g \
-    typescript \
-    typescript-language-server \
-    && rm -rf /root/.npm
-
-# Install Python language server (pyright is included in Serena dependencies)
-# Additional Python tools
-RUN pip install --no-cache-dir \
-    python-lsp-server \
-    pylsp-mypy
-
-# Install gopls (Go language server)
-RUN go install golang.org/x/tools/gopls@latest
+# Install TypeScript language server (minimal)
+RUN npm install -g typescript typescript-language-server && \
+    rm -rf /root/.npm /tmp/*
 
 # Create directories for Serena configuration and caching
 RUN mkdir -p /workspace /tmp/serena-cache /root/.serena
@@ -70,30 +52,25 @@ ENV SERENA_WORKSPACE=/workspace
 ENV SERENA_CACHE_DIR=/tmp/serena-cache
 
 # Create a dummy project to pre-warm Serena's LSP cache
-# This initializes the language servers and caches so they're ready at runtime
-# Focus on Python, Go, and TypeScript which are the primary languages for codex context
+# Focus on Python, Go, and TypeScript for codex context
 RUN mkdir -p /tmp/dummy-project && \
     echo 'def hello(): pass' > /tmp/dummy-project/main.py && \
     echo 'package main\nfunc main() {}' > /tmp/dummy-project/main.go && \
     echo 'export function hello() {}' > /tmp/dummy-project/index.ts
 
-# Pre-index the dummy project to warm up the LSP caches
-# Use --language to specify languages non-interactively and --index to index after creation
-# This ensures pyright, gopls, and typescript-language-server are initialized
+# Pre-index to warm up LSP caches
 RUN serena project create /tmp/dummy-project --name dummy \
     --language python --language go --language typescript \
     --index --log-level INFO --timeout 120 || \
     echo "Pre-indexing completed (some warnings may be expected)"
 
-# Clean up the dummy project but keep the caches
+# Clean up
 RUN rm -rf /tmp/dummy-project
 
 # Expose the workspace directory as a volume mount point
 VOLUME ["/workspace"]
 
 # Set default entrypoint to run Serena MCP server
-# This will start the MCP server on stdio transport
 ENTRYPOINT ["serena-mcp-server"]
 
-# Default arguments (can be overridden)
 CMD []

containers/serena-mcp-server/test-startup-time.sh

@@ -38,7 +38,7 @@ export MCP_GATEWAY_API_KEY=$(openssl rand -base64 45 | tr -d '/+=')
 export WORKSPACE="${WORKSPACE_ARG:-${PWD}}"
 
 GATEWAY_IMAGE="ghcr.io/githubnext/gh-aw-mcpg:v0.0.84"
-SERENA_IMAGE="serena-mcp-server:test"
+SERENA_IMAGE="${SERENA_IMAGE:-serena-mcp-server:slim}"
 
 echo "=== Serena Startup Time Test ==="
 echo "Gateway image: ${GATEWAY_IMAGE}"