Add version-based Docker cache invalidation for uv/opencode

Alternative approach to PR #37 - instead of busting cache on every build,
use git ls-remote to fetch latest version tags and pass them as build args.
Docker layer only rebuilds when tool versions actually change.

- Move uv install from base to runner stage alongside opencode
- Add UV_VERSION and OPENCODE_VERSION build args as cache keys
- Fetch versions via git ls-remote (no API rate limits)
- Log installed versions in build output for debugging

Ref: #37

Author: chriswritescode-dev

.github/workflows/docker-build.yml

@@ -15,6 +15,15 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Get latest tool versions
+        id: versions
+        run: |
+          UV_VERSION=$(git ls-remote --tags --sort=-v:refname https://github.com/astral-sh/uv.git 'refs/tags/[0-9]*' | head -1 | sed 's/.*refs\/tags\///')
+          OPENCODE_VERSION=$(git ls-remote --tags --sort=-v:refname https://github.com/opencode-ai/opencode.git 'refs/tags/v*' | head -1 | sed 's/.*refs\/tags\///')
+          echo "uv=${UV_VERSION}" >> $GITHUB_OUTPUT
+          echo "opencode=${OPENCODE_VERSION}" >> $GITHUB_OUTPUT
+          echo "Detected versions: uv=${UV_VERSION}, opencode=${OPENCODE_VERSION}"
+
       - name: Docker meta
         id: meta
         uses: docker/metadata-action@v5
@@ -47,6 +56,9 @@ jobs:
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+          build-args: |
+            UV_VERSION=${{ steps.versions.outputs.uv }}
+            OPENCODE_VERSION=${{ steps.versions.outputs.opencode }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
           target: runner

Dockerfile

@@ -33,11 +33,6 @@ RUN curl -fsSL https://bun.sh/install | bash && \
     chmod -R 755 /opt/bun && \
     ln -s /opt/bun/bin/bun /usr/local/bin/bun
 
-RUN curl -LsSf https://astral.sh/uv/install.sh | sh && \
-    mv /root/.local/bin/uv /usr/local/bin/uv && \
-    mv /root/.local/bin/uvx /usr/local/bin/uvx && \
-    chmod +x /usr/local/bin/uv /usr/local/bin/uvx
-
 WORKDIR /app
 
 FROM base AS deps
@@ -62,7 +57,15 @@ RUN pnpm --filter frontend build
 
 FROM base AS runner
 
-RUN curl -fsSL https://opencode.ai/install | bash && \
+ARG UV_VERSION=latest
+ARG OPENCODE_VERSION=latest
+
+RUN echo "Installing uv=${UV_VERSION} opencode=${OPENCODE_VERSION}" && \
+    curl -LsSf https://astral.sh/uv/install.sh | UV_NO_MODIFY_PATH=1 sh && \
+    mv /root/.local/bin/uv /usr/local/bin/uv && \
+    mv /root/.local/bin/uvx /usr/local/bin/uvx && \
+    chmod +x /usr/local/bin/uv /usr/local/bin/uvx && \
+    curl -fsSL https://opencode.ai/install | bash -s -- --no-modify-path && \
     mv /root/.opencode /opt/opencode && \
     chmod -R 755 /opt/opencode && \
     ln -s /opt/opencode/bin/opencode /usr/local/bin/opencode