ci: Run full matrix only on Ready to merge or Full CI build labeled PRs (#7689)

Co-authored-by: Bart <bthomee@users.noreply.github.com>

.github/scripts/strategy-matrix/generate.py

@@ -25,24 +25,16 @@ def get_cmake_args(build_type: str, extra_args: str) -> str:
     return " ".join(args)
 
 
-def runs_on_event(exclude_event_types: list[str], event: str | None) -> bool:
-    """Whether a config should run for the current event.
-
-    'exclude_event_types' is a list of GitHub event names (e.g.
-    ["pull_request"]) on which the config should NOT run; an empty list means
-    the config runs on every event. When no event is given (event is None), no
-    filtering is applied.
-    """
-    if event is None:
-        return True
-    return event not in exclude_event_types
-
-
 # ---------------------------------------------------------------------------
 # Input types — shapes of the JSON config files
 # ---------------------------------------------------------------------------
 
 
+# Every config must declare 'minimal'. Minimal configs form the reduced matrix
+# built for pull requests by default; the full matrix adds the rest. Packaging
+# configs declare it too, but packaging is gated in the workflow, not by it.
+
+
 @dataclasses.dataclass
 class LinuxConfig:
     """One entry in linux.json's 'configs' or 'package_configs' arrays."""
@@ -50,13 +42,11 @@ class LinuxConfig:
     compiler: list[str]
     build_type: list[str]
     arch: list[str]
+    minimal: bool
     sanitizers: list[str] = dataclasses.field(default_factory=list)
     suffix: str = ""
     extra_cmake_args: str = ""
     image: str = ""  # only used by package_configs entries
-    # List of GitHub event names (e.g. "pull_request") on which this config
-    # should NOT run. Empty means it runs on every event.
-    exclude_event_types: list[str] = dataclasses.field(default_factory=list)
 
 
 @dataclasses.dataclass
@@ -89,11 +79,9 @@ class PlatformConfig:
     """One entry in macos.json's or windows.json's 'configs' array."""
 
     build_type: list[str]
+    minimal: bool
     build_only: bool = False  # if true, skip tests (e.g. macos/Windows Debug)
     extra_cmake_args: str = ""
-    # List of GitHub event names (e.g. "pull_request") on which this config
-    # should NOT run. Empty means it runs on every event.
-    exclude_event_types: list[str] = dataclasses.field(default_factory=list)
 
     def __post_init__(self) -> None:
         if isinstance(self.build_type, str):
@@ -168,20 +156,18 @@ _ARCHS: dict[str, Architecture] = {
 }
 
 
-def expand_linux_matrix(
-    linux: LinuxFile, event: str | None = None
-) -> list[MatrixEntry]:
+def expand_linux_matrix(linux: LinuxFile, minimal: bool) -> list[MatrixEntry]:
     """Expand a LinuxFile into a flat list of matrix entries.
 
     Each config entry is expanded over the cross-product of its
-    compiler, build_type, sanitizers, and architecture lists. Configs that
-    exclude the current event are skipped.
+    compiler, build_type, sanitizers, and architecture lists. When 'minimal' is
+    true, only configs flagged as minimal are included.
     """
     entries: list[MatrixEntry] = []
 
     for distro, configs in linux.configs.items():
         for cfg in configs:
-            if not runs_on_event(cfg.exclude_event_types, event):
+            if minimal and not cfg.minimal:
                 continue
             # An empty sanitizers list means "one entry with no sanitizer".
             effective_sanitizers = cfg.sanitizers or [""]
@@ -240,19 +226,17 @@ def expand_linux_packaging(linux: LinuxFile) -> list[PackagingEntry]:
     return entries
 
 
-def expand_platform_matrix(
-    pf: PlatformFile, event: str | None = None
-) -> list[MatrixEntry]:
+def expand_platform_matrix(pf: PlatformFile, minimal: bool) -> list[MatrixEntry]:
     """Expand a PlatformFile (macOS or Windows) into matrix entries.
 
-    Configs that exclude the current event are skipped.
+    When 'minimal' is true, only configs flagged as minimal are included.
     """
     platform_name, arch = pf.platform.split("/")
     is_windows = platform_name == "windows"
 
     entries: list[MatrixEntry] = []
     for cfg in pf.configs:
-        if not runs_on_event(cfg.exclude_event_types, event):
+        if minimal and not cfg.minimal:
             continue
         for build_type in cfg.build_type:
             entries.append(
@@ -292,12 +276,12 @@ if __name__ == "__main__":
         action="store_true",
     )
     parser.add_argument(
-        "-e",
-        "--event",
-        help="The GitHub event name that triggered the workflow (e.g. 'push', "
-        "'pull_request'). Configs are filtered by their 'event_type'. If "
-        "omitted, no filtering is applied.",
-        default=None,
+        "-m",
+        "--minimal",
+        help="Emit only the minimal matrix (the configs flagged 'minimal'), "
+        "used for pull requests by default. If omitted, the full matrix is "
+        "emitted.",
+        action="store_true",
     )
     args = parser.parse_args()
 
@@ -308,15 +292,15 @@ if __name__ == "__main__":
     else:
         if args.config in ("linux", None):
             matrix += expand_linux_matrix(
-                LinuxFile.load(THIS_DIR / "linux.json"), args.event
+                LinuxFile.load(THIS_DIR / "linux.json"), args.minimal
             )
         if args.config in ("macos", None):
             matrix += expand_platform_matrix(
-                PlatformFile.load(THIS_DIR / "macos.json"), args.event
+                PlatformFile.load(THIS_DIR / "macos.json"), args.minimal
             )
         if args.config in ("windows", None):
             matrix += expand_platform_matrix(
-                PlatformFile.load(THIS_DIR / "windows.json"), args.event
+                PlatformFile.load(THIS_DIR / "windows.json"), args.minimal
             )
 
     print(f"matrix={json.dumps({'include': [dataclasses.asdict(e) for e in matrix]})}")

.github/scripts/strategy-matrix/linux.json

@@ -2,16 +2,30 @@
   "image_tag": "sha-e29b523",
   "configs": {
     "ubuntu": [
+      {
+        "compiler": ["clang"],
+        "build_type": ["Release"],
+        "arch": ["amd64"],
+        "minimal": true
+      },
+      {
+        "compiler": ["gcc"],
+        "build_type": ["Release"],
+        "arch": ["amd64"],
+        "minimal": false
+      },
       {
         "compiler": ["gcc", "clang"],
         "build_type": ["Debug", "Release"],
-        "arch": ["amd64", "arm64"]
+        "arch": ["arm64"],
+        "minimal": false
       },
 
       {
         "compiler": ["gcc", "clang"],
         "build_type": ["Debug", "Release"],
         "arch": ["amd64"],
+        "minimal": false,
         "sanitizers": ["address", "undefinedbehavior"]
       },
 
@@ -19,6 +33,7 @@
         "compiler": ["gcc"],
         "build_type": ["Debug"],
         "arch": ["amd64"],
+        "minimal": true,
         "suffix": "coverage",
         "extra_cmake_args": "-DUNIT_TEST_REFERENCE_FEE=500 -Dcoverage=ON -Dcoverage_format=xml -DCODE_COVERAGE_VERBOSE=ON -DCMAKE_C_FLAGS=-O0 -DCMAKE_CXX_FLAGS=-O0"
       },
@@ -26,6 +41,7 @@
         "compiler": ["clang"],
         "build_type": ["Debug"],
         "arch": ["amd64"],
+        "minimal": false,
         "suffix": "voidstar",
         "extra_cmake_args": "-Dvoidstar=ON"
       },
@@ -33,6 +49,7 @@
         "compiler": ["clang"],
         "build_type": ["Release"],
         "arch": ["amd64"],
+        "minimal": false,
         "suffix": "reffee",
         "extra_cmake_args": "-DUNIT_TEST_REFERENCE_FEE=1000"
       },
@@ -40,9 +57,9 @@
         "compiler": ["gcc"],
         "build_type": ["Debug"],
         "arch": ["amd64"],
+        "minimal": false,
         "suffix": "unity",
-        "extra_cmake_args": "-Dunity=ON",
-        "exclude_event_types": ["pull_request"]
+        "extra_cmake_args": "-Dunity=ON"
       }
     ],
 
@@ -50,7 +67,8 @@
       {
         "compiler": ["gcc"],
         "build_type": ["Release"],
-        "arch": ["amd64"]
+        "arch": ["amd64"],
+        "minimal": false
       }
     ],
 
@@ -58,7 +76,8 @@
       {
         "compiler": ["gcc"],
         "build_type": ["Release"],
-        "arch": ["amd64"]
+        "arch": ["amd64"],
+        "minimal": false
       }
     ]
   },
@@ -68,6 +87,7 @@
         "compiler": ["gcc"],
         "build_type": ["Release"],
         "arch": ["amd64"],
+        "minimal": false,
         "image": "ghcr.io/xrplf/xrpld/packaging-debian:sha-577d745"
       }
     ],
@@ -77,6 +97,7 @@
         "compiler": ["gcc"],
         "build_type": ["Release"],
         "arch": ["amd64"],
+        "minimal": false,
         "image": "ghcr.io/xrplf/xrpld/packaging-rhel:sha-577d745"
       }
     ]

.github/scripts/strategy-matrix/macos.json

@@ -4,13 +4,14 @@
   "configs": [
     {
       "build_type": "Release",
-      "extra_cmake_args": "-DCMAKE_POLICY_VERSION_MINIMUM=3.5"
+      "extra_cmake_args": "-DCMAKE_POLICY_VERSION_MINIMUM=3.5",
+      "minimal": true
     },
     {
       "build_type": "Debug",
       "extra_cmake_args": "-DCMAKE_POLICY_VERSION_MINIMUM=3.5",
       "build_only": true,
-      "exclude_event_types": ["pull_request"]
+      "minimal": false
     }
   ]
 }

.github/scripts/strategy-matrix/windows.json

@@ -2,11 +2,11 @@
   "platform": "windows/amd64",
   "runner": ["self-hosted", "Windows", "dev-box-windows-2026"],
   "configs": [
-    { "build_type": "Release" },
+    { "build_type": "Release", "minimal": true },
     {
       "build_type": "Debug",
       "build_only": true,
-      "exclude_event_types": ["pull_request"]
+      "minimal": false
     }
   ]
 }

.github/workflows/on-pr.yml

@@ -1,7 +1,11 @@
-# This workflow runs all workflows to check, build and test the project on
-# various Linux flavors, as well as on MacOS and Windows, on every push to a
-# user branch. However, it will not run if the pull request is a draft unless it
-# has the 'DraftRunCI' label. For commits to PRs that target a release branch,
+# This workflow runs workflows to check, build and test the project
+# on every meaningful change on pull_request.
+# However, it will not run if the PR is a draft
+# unless it has the 'DraftRunCI' or 'Full CI build' label.
+#
+# By default a PR builds only a minimal matrix.
+# The full matrix runs once the PR is labeled "Ready to merge" or "Full CI build".
+# For commits to PRs that target a release branch,
 # it also uploads the libxrpl recipe to the Conan remote.
 name: PR
 
@@ -15,9 +19,24 @@ on:
       - reopened
       - synchronize
       - ready_for_review
+      # Trigger on label changes so toggling "Ready to merge" or "Full CI build"
+      # switches between the minimal and full matrix without needing a new push.
+      - labeled
+      - unlabeled
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
+  # Use a per-ref group so a newer run (a push, or a change to a label below)
+  # supersedes the in-progress one for that ref. Label events we don't act on get
+  # their own unique group (per run id) instead, keeping them out of the shared
+  # group so real builds keep running. Keep this list in sync with `should-run`.
+  group: >-
+    ${{ github.workflow }}-${{ github.ref }}${{
+      ((github.event.action == 'labeled' || github.event.action == 'unlabeled')
+      && github.event.label.name != 'Ready to merge'
+      && github.event.label.name != 'DraftRunCI'
+      && github.event.label.name != 'Full CI build')
+      && format('-{0}', github.run_id) || ''
+    }}
   cancel-in-progress: true
 
 defaults:
@@ -26,10 +45,21 @@ defaults:
 
 jobs:
   # This job determines whether the rest of the workflow should run. It runs
-  # when the PR is not a draft (which should also cover merge-group) or
-  # has the 'DraftRunCI' label.
+  # when the PR is not a draft (which should also cover merge-group) or has the
+  # 'DraftRunCI' or 'Full CI build' label. For label events it only runs when the
+  # label added or removed is one we act on ('Ready to merge', 'DraftRunCI' or
+  # 'Full CI build'), so unrelated label changes do not trigger a redundant run.
   should-run:
-    if: ${{ !github.event.pull_request.draft || contains(github.event.pull_request.labels.*.name, 'DraftRunCI') }}
+    if: >-
+      ${{
+        ((github.event.action != 'labeled' && github.event.action != 'unlabeled')
+          || github.event.label.name == 'Ready to merge'
+          || github.event.label.name == 'DraftRunCI'
+          || github.event.label.name == 'Full CI build')
+        && (!github.event.pull_request.draft
+          || contains(github.event.pull_request.labels.*.name, 'DraftRunCI')
+          || contains(github.event.pull_request.labels.*.name, 'Full CI build'))
+      }}
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
@@ -91,15 +121,17 @@ jobs:
         # least one of:
         # * Any of the files checked in the `changes` step were modified
         # * The PR is NOT a draft and is labeled "Ready to merge"
+        # * The PR is labeled "Full CI build" (draft or not)
         # * The workflow is running from the merge queue
         id: go
         env:
           FILES: ${{ steps.changes.outputs.any_changed }}
           DRAFT: ${{ github.event.pull_request.draft }}
           READY: ${{ contains(github.event.pull_request.labels.*.name, 'Ready to merge') }}
+          FULL: ${{ contains(github.event.pull_request.labels.*.name, 'Full CI build') }}
           MERGE: ${{ github.event_name == 'merge_group' }}
         run: |
-          echo "go=${{ (env.DRAFT != 'true' && env.READY == 'true') || env.FILES == 'true' || env.MERGE == 'true' }}" >>"${GITHUB_OUTPUT}"
+          echo "go=${{ (env.DRAFT != 'true' && env.READY == 'true') || env.FULL == 'true' || env.FILES == 'true' || env.MERGE == 'true' }}" >>"${GITHUB_OUTPUT}"
           cat "${GITHUB_OUTPUT}"
     outputs:
       go: ${{ steps.go.outputs.go == 'true' }}
@@ -142,7 +174,10 @@ jobs:
 
   package:
     needs: [should-run, build-test]
-    if: ${{ needs.should-run.outputs.go == 'true' }}
+    # Packaging consumes the debian/rhel release binaries, which are only built
+    # by the full matrix. Skip it for pull requests that ran only the minimal
+    # matrix (i.e. not yet labeled "Ready to merge" or "Full CI build").
+    if: ${{ needs.should-run.outputs.go == 'true' && (github.event_name != 'pull_request' || contains(github.event.pull_request.labels.*.name, 'Ready to merge') || contains(github.event.pull_request.labels.*.name, 'Full CI build')) }}
     uses: ./.github/workflows/reusable-package.yml
 
   upload-recipe:

.github/workflows/reusable-strategy-matrix.yml

@@ -35,5 +35,8 @@ jobs:
         id: generate
         env:
           GENERATE_CONFIG: ${{ inputs.os != '' && format('--config={0}', inputs.os) || '' }}
-          GENERATE_EVENT: ${{ github.event_name }}
-        run: ./generate.py ${GENERATE_CONFIG} --event="${GENERATE_EVENT}" >>"${GITHUB_OUTPUT}"
+          # Run only the minimal matrix for pull requests that are not yet
+          # labeled "Ready to merge" or "Full CI build". Any other event (merge
+          # queue, push, schedule, manual dispatch) runs the full matrix.
+          GENERATE_MINIMAL: ${{ (github.event_name == 'pull_request' && !contains(github.event.pull_request.labels.*.name, 'Ready to merge') && !contains(github.event.pull_request.labels.*.name, 'Full CI build')) && '--minimal' || '' }}
+        run: ./generate.py ${GENERATE_CONFIG} ${GENERATE_MINIMAL} >>"${GITHUB_OUTPUT}"