Container Build Caching (#509)

## Summary

<!--
Include a short paragraph of the changes introduced in this PR.
If this PR requires additional context or rationale, explain why
the changes are necessary.
-->
Store `dnf` and `uv` caches in a GitHub Action cache.

## Details

<!--
Provide a detailed list of all changes introduced in this pull request.
-->
Adds mount caches for `dnf` and `uv` to container image and stores their
output into a action cache. Layer caching would probably be more
efficient but requires a container repository for storing the
intermediate layers.

## Test Plan

<!--
List the steps needed to test this PR.
-->
Rerun the container build job and observe that build takes less time and
skips download steps.

---

- [x] "I certify that all code in this PR is my own, except as noted
below."

## Use of AI

- [ ] Includes AI-assisted code completion
- [ ] Includes code generated by an AI application
- [ ] Includes AI-generated tests (NOTE: AI written tests should have a
docstring that includes `## WRITTEN BY AI ##`)

Author: sjmonson

.github/workflows/development.yml

@@ -142,6 +142,12 @@ jobs:
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
+      - name: Store/retrieve build caches
+        id: cache-buildah
+        uses: actions/cache@v4
+        with:
+          path: /var/tmp/buildah-cache-*
+          key: buildah-mount-cache-${{ runner.os }}-${{ runner.arch }}
       - name: Buildah build
         id: build-image
         uses: redhat-actions/buildah-build@v2
@@ -150,6 +156,7 @@ jobs:
           build-args: |
             GUIDELLM_BUILD_TYPE=dev
           tags: "pr-${{ github.event.number }}"
+          layers: true
           containerfiles: |
             ./Containerfile
       - name: Push To ghcr.io

.github/workflows/release-candidate.yml

@@ -185,14 +185,20 @@ jobs:
         if: ${{ env.package_version == '' }}
         run: |
           exit 1
+      - name: Store/retrieve build caches
+        id: cache-buildah
+        uses: actions/cache@v4
+        with:
+          path: /var/tmp/buildah-cache-*
+          key: buildah-mount-cache-${{ runner.os }}-${{ runner.arch }}
       - name: Buildah build
         id: build-image
         uses: redhat-actions/buildah-build@v2
         with:
           image: ${{ github.event.repository.name }}
           build-args: |
             GUIDELLM_BUILD_TYPE=candidate
-          tags: ${{ env.package_version }}~rc
+          tags: ${{ env.package_version }}-rc
           containerfiles: |
             ./Containerfile
       - name: Push To ghcr.io

.github/workflows/release.yml

@@ -184,6 +184,12 @@ jobs:
         if: ${{ env.package_version == '' }}
         run: |
           exit 1
+      - name: Store/retrieve build caches
+        id: cache-buildah
+        uses: actions/cache@v4
+        with:
+          path: /var/tmp/buildah-cache-*
+          key: buildah-mount-cache-${{ runner.os }}-${{ runner.arch }}
       - name: Buildah build
         id: build-image
         uses: redhat-actions/buildah-build@v2

Containerfile

@@ -10,28 +10,47 @@ FROM $BASE_IMAGE as builder
 # dev: increment to next minor, add 'dev' with build iteration
 ARG GUIDELLM_BUILD_TYPE=dev
 
+# Extra dependencies to install
+# all: install all extras
+# recommended: install recommended extras
+ARG GUIDELLM_BUILD_EXTRAS=all
+
 # Switch to root for installing packages
 USER root
 
-# Install build tooling
-RUN dnf install -y git \
-    && /usr/bin/python3 -m venv /tmp/uv \
+# Install uv in a temporary venv
+RUN /usr/bin/python3 -m venv /tmp/uv \
     && /tmp/uv/bin/pip install --no-cache-dir -U uv \
     && ln -s /tmp/uv/bin/uv /usr/local/bin/uv
 
-# Set the default venv for uv
-# Copy instead of link files with uv
+# Install build dependencies
+RUN --mount=type=cache,sharing=locked,target=/var/cache/dnf \
+    dnf install -y git
+
 # Set correct build type for versioning
-ENV VIRTUAL_ENV=/opt/app-root \
+# Configure uv for building guidellm
+ENV GUIDELLM_BUILD_TYPE=$GUIDELLM_BUILD_TYPE \
+    VIRTUAL_ENV=/opt/app-root \
+    UV_PROJECT="/src" \
     UV_LINK_MODE="copy" \
-    GUIDELLM_BUILD_TYPE=$GUIDELLM_BUILD_TYPE
+    UV_NO_DEV="1" \
+    UV_NO_EDITABLE="1" \
+    UV_FROZEN="1" \
+    UV_CACHE_DIR="/tmp/uv_cache"
+
+# Sync initial environment
+RUN --mount=type=cache,target=$UV_CACHE_DIR \
+    --mount=type=bind,source=uv.lock,target=$UV_PROJECT/uv.lock,relabel=shared \
+    --mount=type=bind,source=pyproject.toml,target=$UV_PROJECT/pyproject.toml,relabel=shared \
+    uv sync --active --no-install-project --extra $GUIDELLM_BUILD_EXTRAS
 
 # Copy repository files
 # Do this as late as possible to leverage layer caching
-COPY / /src
+COPY / $UV_PROJECT
 
-# Install guidellm and locked dependencies
-RUN uv sync --active --project /src --frozen --no-dev --extra all --no-editable
+# Install guidellm
+RUN --mount=type=cache,target=$UV_CACHE_DIR \
+    uv sync --active --extra $GUIDELLM_BUILD_EXTRAS
 
 # Prod image
 FROM $BASE_IMAGE
@@ -40,9 +59,9 @@ FROM $BASE_IMAGE
 USER root
 
 # Install some helpful utilities and deps
-RUN dnf install -y --setopt=install_weak_deps=False \
-        vi tar rsync ffmpeg-free \
-    && dnf clean all
+RUN --mount=type=cache,sharing=locked,target=/var/cache/dnf \
+    dnf install -y --setopt=install_weak_deps=False \
+        vi tar rsync ffmpeg-free
 
 # Switch back to unpriv user
 # Root group for k8s