tests: bootstrap spread

This is "just enough" spread to run locally considering one has google
credentials to run with.

Signed-off-by: Sergio Schvezov <[email protected]>

Author: sergiusens

.gitmodules

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+[submodule "tools/external"]
+	path = tools/external
+	url = https://github.com/snapcore/snapd-testing-tools.git

spread.yaml

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+project: charmcraft
+
+path: /charmcraft
+environment:
+  PROJECT_PATH: /charmcraft
+  PATH: /snap/bin:$PATH:$PROJECT_PATH/tools/external/tools
+
+backends:
+  google:
+    key: '$(HOST: echo "$SPREAD_GOOGLE_KEY")'
+    location: snapd-spread/us-east1-b
+    halt-timeout: 2h
+    systems:
+      - ubuntu-18.04-64:
+          workers: 1
+          storage: 40G
+      - ubuntu-20.04-64:
+          workers: 1
+          storage: 40G
+      - ubuntu-22.04-64:
+          workers: 1
+          storage: 40G
+      - fedora-35-64:
+          workers: 1
+          storage: 40G
+
+prepare: |
+  set -e
+  if os.query is-ubuntu; then
+    tempfile="$(mktemp)"
+    if ! apt-get update > "$tempfile" 2>&1; then
+        cat "$tempfile"
+        exit 1
+    fi
+  fi
+
+  tests.pkgs install snapd
+
+  snap wait system seed.loaded
+
+  # The /snap directory does not exist in some environments
+  [ ! -d /snap ] && ln -s /var/lib/snapd/snap /snap
+
+  snap install lxd
+
+  # Hold snap refreshes for 24h.
+  snap set system refresh.hold="$(date --date=tomorrow +%Y-%m-%dT%H:%M:%S%:z)"
+  if ! snap watch --last=auto-refresh?; then
+      journalctl -xe
+  fi
+  if ! snap watch --last=install?; then
+      journalctl -xe
+  fi
+
+  lxd waitready --timeout=30
+  lxd init --auto
+
+  if stat /charmcraft/charmcraft_*.snap 2>/dev/null; then
+    snap install --classic --dangerous /charmcraft/charmcraft_*.snap
+  else
+    echo "Expected a snap to exist in /charmcraft/"
+    exit 1
+  fi
+
+suites:
+  tests/spread/commands/:
+    summary: simple charmcraft commands

tests/spread/commands/version/task.yaml

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+summary: simple version command probe
+
+execute: |
+  if ! charmcraft version; then
+      echo charmcraft version command is not working
+      exit 1
+  fi