Deliberately trigger CI workflows based on what files were changed (#…

…2213)

* Add Readme

* Trigger more carefully

* Specifically trigger workflows

.github/workflows/README.md

@@ -0,0 +1,25 @@
+<!---
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements.  See the NOTICE file
+  distributed with this work for additional information
+  regarding copyright ownership.  The ASF licenses this file
+  to you under the Apache License, Version 2.0 (the
+  "License"); you may not use this file except in compliance
+  with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing,
+  software distributed under the License is distributed on an
+  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+  KIND, either express or implied.  See the License for the
+  specific language governing permissions and limitations
+  under the License.
+-->
+
+The CI is structured so most tests are run in specific workflows:
+`arrow.yml` for `arrow`, `parquet.yml` for `parquet` and so on.
+
+The basic idea is to run all tests on pushes to master (to ensure we
+keep master green) but run only the individual workflows on PRs that
+change files that could affect them.

.github/workflows/arrow_flight.yml

@@ -19,8 +19,17 @@
 # tests for arrow_flight crate
 name: arrow_flight
 
+
+# trigger for all PRs that touch certain files and changes to master
 on:
+  push:
+    branches:
+      - master
   pull_request:
+    paths:
+      - arrow/**
+      - arrow-flight/**
+      - .github/**
 
 jobs:
   # test the crate

.github/workflows/cancel.yml

@@ -15,6 +15,7 @@
 # specific language governing permissions and limitations
 # under the License.
 
+# Attempt to cancel stale workflow runs to save github actions runner time
 name: Cancel stale runs
 
 on:

.github/workflows/dev.yml

@@ -17,9 +17,11 @@
 
 name: Dev
 
+# trigger for all PRs and changes to master
 on:
-  # always trigger
   push:
+    branches:
+      - master
   pull_request:
 
 env:

.github/workflows/dev_pr.yml

@@ -17,6 +17,7 @@
 
 name: Dev PR
 
+# Trigger whenever a PR is changed (title as well as new / changed commits)
 on:
   pull_request_target:
     types:
@@ -41,9 +42,3 @@ jobs:
           repo-token: ${{ secrets.GITHUB_TOKEN }}
           configuration-path: .github/workflows/dev_pr/labeler.yml
           sync-labels: true
-
-      #- name: Checks if PR needs rebase
-      #  uses: eps1lon/actions-label-merge-conflict@releases/2.x
-      #  with:
-      #    dirtyLabel: "needs-rebase"
-      #    repoToken: "${{ secrets.GITHUB_TOKEN }}"

.github/workflows/docs.yml

@@ -17,8 +17,8 @@
 
 name: Docs
 
+# trigger for all PRs and changes to master
 on:
-  # always trigger
   push:
     branches:
       - master

.github/workflows/integration.yml

@@ -17,14 +17,16 @@
 
 name: Integration
 
-# Only run when arrow or github changes
+# trigger for all PRs that touch certain files and changes to master
 on:
   push:
     branches:
       - master
   pull_request:
     paths:
       - arrow/**
+      - arrow-pyarrow-integration-testing/**
+      - integration-testing/**
       - .github/**
 
 jobs:

.github/workflows/miri.yaml

@@ -17,12 +17,15 @@
 
 name: MIRI
 
+# trigger for all PRs that touch certain files and changes to master
 on:
-  # always trigger
   push:
     branches:
       - master
   pull_request:
+    paths:
+      - arrow/**
+      - .github/**
 
 jobs:
   miri-checks:

.github/workflows/object_store.yml

@@ -16,16 +16,16 @@
 # under the License.
 
 ---
-# tests for object_store crate
+# tests for `object_store` crate
 name: object_store
 
+# trigger for all PRs that touch certain files and changes to master
 on:
   push:
     branches:
       - master
   pull_request:
     paths:
-      # Only run when object store files or github workflows change
       - object_store/**
       - .github/**
 

.github/workflows/parquet.yml

@@ -19,12 +19,17 @@
 # tests for parquet crate
 name: "parquet"
 
+
+# trigger for all PRs that touch certain files and changes to master
 on:
-  # always trigger
   push:
     branches:
       - master
   pull_request:
+    paths:
+      - arrow/**
+      - parquet/**
+      - .github/**
 
 jobs:
   # test the crate

.github/workflows/parquet_derive.yml

@@ -19,8 +19,18 @@
 # tests for parquet_derive crate
 name: parquet_derive
 
+
+# trigger for all PRs that touch certain files and changes to master
 on:
+  push:
+    branches:
+      - master
   pull_request:
+    paths:
+      - parquet/**
+      - parquet_derive/**
+      - parquet_derive_test/**
+      - .github/**
 
 jobs:
   # test the crate

.github/workflows/rust.yml

@@ -15,17 +15,20 @@
 # specific language governing permissions and limitations
 # under the License.
 
+# tests for workspace wide
 name: Rust
 
+# trigger for all PRs and changes to master
 on:
-  # always trigger
   push:
     branches:
       - master
   pull_request:
 
 jobs:
 
+  # Check workspace wide compile and test with default features for
+  # mac and windows
   windows-and-macos:
     name: Test on ${{ matrix.os }} Rust ${{ matrix.rust }}
     runs-on: ${{ matrix.os }}
@@ -75,6 +78,7 @@ jobs:
         run: |
           cargo check --benches --workspace --features test_common,prettyprint,async,experimental
 
+  # Run cargo fmt for all crates
   lint:
     name: Lint (cargo fmt)
     runs-on: ubuntu-latest