add basic spread infrastructure

.github/workflows/build-rock.yaml

@@ -1,4 +1,4 @@
-name: Build rock
+name: Build and test rock
 
 on:
   pull_request:
@@ -33,5 +33,32 @@ jobs:
       - name: Upload rock
         uses: actions/upload-artifact@v4
         with:
-          name: snapcraft-${{ steps.vars.outputs.rockname }}.rock
+          name: snapcraft-rock
           path: '*.rock'
+
+  spread-tests:
+    runs-on: self-hosted
+    needs: [build-rock]
+
+    steps:
+      - name: Cleanup job workspace
+        run: |
+          rm -rf "${{ github.workspace }}"
+          mkdir "${{ github.workspace }}"
+
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          submodules: true
+
+      - name: Download rock artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: snapcraft-rock
+          path: tests
+
+      # NOTE: Actually running spread is disabled until we have runners that
+      # support the tool.
+      # - name: Run spread
+      #   run: spread

.gitignore

@@ -1,2 +1,5 @@
 *.rock
+tests/spread/**/parts
+tests/spread/**/prime
+tests/spread/**/stage
 

.gitmodules

@@ -0,0 +1,4 @@
+[submodule "tools/external/snapd-testing-tools"]
+	path = tools/external/snapd-testing-tools
+	url = https://github.com/snapcore/snapd-testing-tools.git
+	branch = main

spread.yaml

@@ -0,0 +1,90 @@
+project: snapcraft-rocks
+
+# note: the `path` is inside /root because the docker snap has issues
+# mounting directories that are outside the user's home
+path: /root/snapcraft-rocks
+environment:
+  PROJECT_PATH: /root/snapcraft-rocks
+  SNAPD_TESTING_TOOLS: $PROJECT_PATH/tools/external/snapd-testing-tools/tools
+  PATH: /snap/bin:$PATH:$SNAPD_TESTING_TOOLS:$PROJECT_PATH/tools/spread
+  # These variables are used to set the base in multi-base projects
+  SNAPCRAFT_BASE: core22
+  SNAPCRAFT_BUILD_BASE: core22
+
+include:
+    - tests/
+    - tools/
+
+backends:
+  google:
+    key: '$(HOST: echo "$SPREAD_GOOGLE_KEY")'
+    location: snapd-spread/us-east1-b
+    halt-timeout: 2h
+    systems:
+      - ubuntu-20.04-64:
+          workers: 1
+          storage: 40G
+      - ubuntu-22.04-64:
+          workers: 1
+          storage: 40G
+      - fedora-39-64:
+          workers: 1
+          storage: 40G
+
+prepare: |
+  # if the 'tools' directory inside the submodule does not exist, then assume the submodule is empty
+  if [[ ! -d "$SNAPD_TESTING_TOOLS" ]]; then
+    echo "Cannot run spread because submodule 'snapd-testing-tools' is empty. Fetch with 'git submodule update --init' and rerun spread."
+    exit 1
+  fi
+
+  if os.query is-ubuntu; then
+    tempfile="$(mktemp)"
+    if ! apt-get update > "$tempfile" 2>&1; then
+        cat "$tempfile"
+        exit 1
+    fi
+  fi
+
+  tests.pkgs install snapd
+
+  snap wait system seed.loaded
+
+  # The /snap directory does not exist in some environments
+  [ ! -d /snap ] && ln -s /var/lib/snapd/snap /snap
+
+  # Hold snap refreshes.
+  snap refresh --hold
+
+  if ! snap watch --last=auto-refresh?; then
+      journalctl -xe
+  fi
+  if ! snap watch --last=install?; then
+      journalctl -xe
+  fi
+
+  if [ "$SPREAD_SYSTEM" = "fedora-39-64" ]; then
+    # Latest docker snap needs a more recent version of snapd than Fedora ships
+    # https://github.com/canonical/rockcraft/pull/277
+    snap install docker --channel=core18/stable
+  else
+    snap install docker
+  fi  
+
+  # make sure docker is working
+  retry -n 10 --wait 2 sh -c 'docker run --rm hello-world'
+
+  # install rockcraft just to use its bundled skopeo
+  snap install --classic --stable rockcraft
+
+  load_snapcraft_rock
+
+
+restore-each: |
+  # Cleanup after each task.
+  rm -f *.snap
+
+
+suites:
+  tests/spread/general/:
+    summary: general tests that should work on all bases and Snapcraft versions

tests/spread/general/hello/snap/snapcraft.yaml

@@ -0,0 +1,17 @@
+name: hello-world
+version: "1.0"
+summary: test
+description: hello-world
+grade: devel
+confinement: strict
+base: SNAPCRAFT_BASE
+build-base: SNAPCRAFT_BUILD_BASE
+
+parts:
+  hello-world:
+    plugin: nil
+    stage-packages: ["hello"]
+
+apps:
+  hello-world:
+    command: usr/bin/hello

tests/spread/general/hello/task.yaml

@@ -0,0 +1,9 @@
+summary: build & run a basic "hello world" snap
+
+execute: |
+  # pack the snap
+  run_snapcraft pack
+
+  # install & run it
+  snap install --dangerous hello-world_1.0_amd64.snap
+  hello-world -g "hello-from-snap" | MATCH "hello-from-snap"

tools/spread/load_snapcraft_rock

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+# load_snapcraft_rock: helper to load the Snapcraft rock into docker.
+# 
+# The rock is always loaded as "snapcraft-rock", regardless of supported base. 
+
+if stat ${PROJECT_PATH}/tests/*.rock 2>/dev/null; then
+  rockname=$(ls ${PROJECT_PATH}/tests/*.rock)
+  /snap/rockcraft/current/bin/skopeo --insecure-policy copy oci-archive:${rockname} docker-daemon:snapcraft-rock:latest
+else
+  echo "Expected a rock to exist in ${PROJECT_PATH}/tests/"
+  exit 1
+fi

tools/spread/run_snapcraft

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+# run_snapcraft: helper to run Snapcraft inside a container.
+
+# replace the SNAPCRAFT_* tokens with the correct values for our Snapcraft image
+sed --in-place='' "s/SNAPCRAFT_BASE/$SNAPCRAFT_BASE/" snap/snapcraft.yaml
+sed --in-place='' "s/SNAPCRAFT_BUILD_BASE/$SNAPCRAFT_BUILD_BASE/" snap/snapcraft.yaml
+docker run --rm -v `pwd`:/project snapcraft-rock:latest "$@"