feat(snap): switch to prebuilt binaries shared with other packages (#1651)

Switch the snapcraft build from 'source: .' (which copies the full
20 GB repo including 18 GB of target/ and build artifacts into LXD)
to 'source: ./snap/prebuilt' (~130 MB of only the binaries and
metadata that snapcraft needs).

The snap-package workflow now downloads the same cli, gateway, and
supervisor binaries that other packaging jobs (deb, rpm, tarballs)
use. A new 'Prepare snap build directory' step assembles snap/prebuilt/
with the 3 binaries, gateway wrapper script, LICENSE, README.md, and
a precomputed version string — everything snapcraft needs without
any source tree access.

This addresses CI/CD Improvements (issue #1361) by reducing data
transferred into the LXD sandbox by ~150x and eliminating the need
for snapcraft to traverse the entire repository tree.

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>

.github/workflows/release-dev.yml

@@ -654,7 +654,7 @@ jobs:
 
   build-snap:
     name: Build Snap
-    needs: [compute-versions]
+    needs: [compute-versions, build-cli-linux, build-gateway-binary-linux, build-supervisor-binary-linux]
     uses: ./.github/workflows/snap-package.yml
     with:
       checkout-ref: ${{ github.sha }}

.github/workflows/release-tag.yml

@@ -690,7 +690,7 @@ jobs:
 
   build-snap:
     name: Build Snap
-    needs: [compute-versions]
+    needs: [compute-versions, build-cli-linux, build-gateway-binary-linux, build-supervisor-binary-linux]
     uses: ./.github/workflows/snap-package.yml
     with:
       checkout-ref: ${{ inputs.tag || github.ref }}

.github/workflows/snap-package.yml

@@ -76,6 +76,59 @@ jobs:
           set -euo pipefail
           sudo snap install snapcraft --classic
 
+      - name: Download prebuilt CLI binary
+        uses: actions/download-artifact@3e5f45b2cfb9172054b40e67214ff5f5447ce83dd # v8
+        with:
+          name: cli-linux-${{ matrix.arch }}
+          path: prebuilt/cli
+
+      - name: Download prebuilt gateway binary
+        uses: actions/download-artifact@3e5f45b2cfb9172054b40e67214ff5f5447ce83dd # v8
+        with:
+          name: gateway-binary-linux-${{ matrix.arch }}
+          path: prebuilt/gateway
+
+      - name: Download prebuilt sandbox binary
+        uses: actions/download-artifact@3e5f45b2cfb9172054b40e67214ff5f5447ce83dd # v8
+        with:
+          name: supervisor-binary-linux-${{ matrix.arch }}
+          path: prebuilt/sandbox
+
+      - name: Extract prebuilt binaries
+        run: |
+          set -euo pipefail
+          mkdir -p prebuilt/{cli,gateway,sandbox}
+
+          for d in cli gateway sandbox; do
+            for tarball in prebuilt/$d/*.tar.gz; do
+              if [ -f "$tarball" ]; then
+                tar -xzf "$tarball" -C "prebuilt/$d"
+              else
+                echo "WARNING: no tarball found in prebuilt/$d/" >&2
+              fi
+            done
+          done
+          ls -laR prebuilt/
+
+      - name: Prepare snap build directory
+        run: |
+          set -euo pipefail
+          mkdir -p snap/prebuilt
+
+          cp prebuilt/cli/openshell snap/prebuilt/openshell
+          cp prebuilt/gateway/openshell-gateway snap/prebuilt/openshell-gateway
+          cp prebuilt/sandbox/openshell-sandbox snap/prebuilt/openshell-sandbox
+
+          cp deploy/snap/bin/openshell-gateway-wrapper snap/prebuilt/
+          cp LICENSE snap/prebuilt/
+          cp README.md snap/prebuilt/
+
+          mkdir -p snap/prebuilt/meta/gui
+          cp snap/local/term.desktop snap/prebuilt/meta/gui/term.desktop
+          cp snap/local/icon.png snap/prebuilt/meta/gui/icon.png
+
+          python3 tasks/scripts/release.py get-version --snap > snap/prebuilt/version
+
       - name: Build snap
         run: |
           set -euo pipefail

snapcraft.yaml

@@ -69,43 +69,44 @@ apps:
 
 parts:
   openshell:
-    plugin: rust
-    rust-channel: "1.95.0"
-    source: .
-    build-packages:
-      - build-essential
-      - ca-certificates
-      - clang
-      - cmake
-      - git
-      - libclang-dev
-      - libssl-dev
-      - libz3-dev
-      - pkg-config
-      - python3
+    plugin: nil
+    source: ./snap/prebuilt
     override-pull: |
       craftctl default
-      craftctl set version="$(python3 "$CRAFT_PROJECT_DIR/tasks/scripts/release.py" get-version --snap)"
+      craftctl set version="$(cat "$CRAFT_PART_SRC/version")"
     override-build: |
       set -euo pipefail
 
-      cargo build --release --locked -p openshell-cli --features bundled-z3
-      cargo build --release --locked -p openshell-server --bin openshell-gateway --features bundled-z3
-      cargo build --release --locked -p openshell-sandbox --bin openshell-sandbox
+      MISSING=()
+      for bin in openshell openshell-gateway openshell-sandbox openshell-gateway-wrapper; do
+        if [ ! -f "$CRAFT_PART_SRC/$bin" ]; then
+          MISSING+=("$bin")
+        fi
+      done
 
-      install -D -m 0755 "$CRAFT_PART_BUILD/target/release/openshell" \
+      if [ ${#MISSING[@]} -gt 0 ]; then
+        printf '%s\n' \
+          "ERROR: snap/prebuilt/ is incomplete:" \
+          "${MISSING[@]/#/'  - '}" \
+          "" \
+          "The snap build directory must be populated by CI before snapcraft pack." \
+          >&2
+        exit 1
+      fi
+
+      install -D -m 0755 "$CRAFT_PART_SRC/openshell" \
         "$CRAFT_PART_INSTALL/bin/openshell"
-      install -D -m 0755 "$CRAFT_PART_BUILD/target/release/openshell-gateway" \
+      install -D -m 0755 "$CRAFT_PART_SRC/openshell-gateway" \
         "$CRAFT_PART_INSTALL/bin/openshell-gateway"
-      install -D -m 0755 "$CRAFT_PART_BUILD/target/release/openshell-sandbox" \
+      install -D -m 0755 "$CRAFT_PART_SRC/openshell-sandbox" \
         "$CRAFT_PART_INSTALL/bin/openshell-sandbox"
-      install -D -m 0755 "$CRAFT_PROJECT_DIR/tasks/scripts/snap-gateway-wrapper.sh" \
+      install -D -m 0755 "$CRAFT_PART_SRC/openshell-gateway-wrapper" \
         "$CRAFT_PART_INSTALL/bin/openshell-gateway-wrapper"
-      install -D -m 0644 "$CRAFT_PROJECT_DIR/snap/local/term.desktop" \
+      install -D -m 0644 "$CRAFT_PART_SRC/meta/gui/term.desktop" \
         "$CRAFT_PART_INSTALL/meta/gui/term.desktop"
-      install -D -m 0644 "$CRAFT_PROJECT_DIR/snap/local/icon.png" \
+      install -D -m 0644 "$CRAFT_PART_SRC/meta/gui/icon.png" \
         "$CRAFT_PART_INSTALL/meta/gui/icon.png"
-      install -D -m 0644 "$CRAFT_PROJECT_DIR/LICENSE" \
+      install -D -m 0644 "$CRAFT_PART_SRC/LICENSE" \
         "$CRAFT_PART_INSTALL/usr/share/doc/openshell/LICENSE"
-      install -D -m 0644 "$CRAFT_PROJECT_DIR/README.md" \
+      install -D -m 0644 "$CRAFT_PART_SRC/README.md" \
         "$CRAFT_PART_INSTALL/usr/share/doc/openshell/README.md"