Rename the main branch of the Airflow repo to be main (#16149)

.asf.yaml

@@ -41,7 +41,7 @@ github:
     rebase: false
 
   protected_branches:
-    master:
+    main:
       required_pull_request_reviews:
         required_approving_review_count: 1
     v1-10-stable:

.github/PULL_REQUEST_TEMPLATE.md

@@ -17,7 +17,7 @@ http://chris.beams.io/posts/git-commit/
 ---
 **^ Add meaningful description above**
 
-Read the **[Pull Request Guidelines](https://github.com/apache/airflow/blob/master/CONTRIBUTING.rst#pull-request-guidelines)** for more information.
+Read the **[Pull Request Guidelines](https://github.com/apache/airflow/blob/main/CONTRIBUTING.rst#pull-request-guidelines)** for more information.
 In case of fundamental code change, Airflow Improvement Proposal ([AIP](https://cwiki.apache.org/confluence/display/AIRFLOW/Airflow+Improvements+Proposals)) is needed.
 In case of a new dependency, check compliance with the [ASF 3rd Party License Policy](https://www.apache.org/legal/resolved.html#category-x).
-In case of backwards incompatible changes please leave a note in [UPDATING.md](https://github.com/apache/airflow/blob/master/UPDATING.md).
+In case of backwards incompatible changes please leave a note in [UPDATING.md](https://github.com/apache/airflow/blob/main/UPDATING.md).

.github/boring-cyborg.yml

@@ -199,20 +199,20 @@ labelerFlags:
 firstPRWelcomeComment: >
   Congratulations on your first Pull Request and welcome to the Apache Airflow community!
   If you have any issues or are unsure about any anything please check our
-  Contribution Guide (https://github.com/apache/airflow/blob/master/CONTRIBUTING.rst)
+  Contribution Guide (https://github.com/apache/airflow/blob/main/CONTRIBUTING.rst)
 
   Here are some useful points:
 
   - Pay attention to the quality of your code (flake8, pylint and type annotations). Our [pre-commits](
-  https://github.com/apache/airflow/blob/master/STATIC_CODE_CHECKS.rst#prerequisites-for-pre-commit-hooks)
+  https://github.com/apache/airflow/blob/main/STATIC_CODE_CHECKS.rst#prerequisites-for-pre-commit-hooks)
   will help you with that.
 
   - In case of a new feature add useful documentation (in docstrings or in `docs/` directory).
   Adding a new operator? Check this short
-  [guide](https://github.com/apache/airflow/blob/master/docs/apache-airflow/howto/custom-operator.rst)
+  [guide](https://github.com/apache/airflow/blob/main/docs/apache-airflow/howto/custom-operator.rst)
   Consider adding an example DAG that shows how users should use it.
 
-  - Consider using [Breeze environment](https://github.com/apache/airflow/blob/master/BREEZE.rst) for testing
+  - Consider using [Breeze environment](https://github.com/apache/airflow/blob/main/BREEZE.rst) for testing
   locally, it’s a heavy docker but it ships with a working Airflow and a lot of integrations.
 
   - Be patient and persistent. It might take some time to get a review or get the final approval from
@@ -222,7 +222,7 @@ firstPRWelcomeComment: >
   communication including (but not limited to) comments on Pull Requests, Mailing list and Slack.
 
   - Be sure to read the [Airflow Coding style](
-  https://github.com/apache/airflow/blob/master/CONTRIBUTING.rst#coding-style-and-best-practices).
+  https://github.com/apache/airflow/blob/main/CONTRIBUTING.rst#coding-style-and-best-practices).
 
   Apache Airflow is a community-driven project and together we are making it better 🚀.
 

.github/workflows/build-images.yml

@@ -22,7 +22,7 @@ on:  # yamllint disable-line rule:truthy
     - cron: '28 0 * * *'
   pull_request_target:
   push:
-    branches: ['main', 'master', 'v1-10-test', 'v1-10-stable', 'v2-0-test']
+    branches: ['main', 'v1-10-test', 'v1-10-stable', 'v2-0-test']
 env:
   MOUNT_SELECTED_LOCAL_SOURCES: "false"
   FORCE_ANSWER_TO_QUESTIONS: "yes"
@@ -130,7 +130,7 @@ jobs:
     strategy:
       matrix:
         # We need to attempt to build all possible versions here because pull_request_target
-        # event is run from master for both master and v1-10-tests
+        # event is run for both main and v1-10-tests
         python-version: ${{ fromJson(needs.build-info.outputs.allPythonVersions) }}
       fail-fast: true
     if: needs.build-info.outputs.image-build == 'true'
@@ -158,7 +158,7 @@ jobs:
         # We cannot "source" the script here because that would be a security problem (we cannot run
         # any code that comes from the sources coming from the PR. Therefore we extract the
         # DEFAULT_BRANCH and DEFAULT_CONSTRAINTS_BRANCH via custom grep/awk/sed commands
-        # Also 2.7 and 3.5 versions are not allowed to proceed on master
+        # Also 2.7 and 3.5 versions are not allowed to proceed on main
         id: defaults
         run: |
           DEFAULT_BRANCH=$(grep "export DEFAULT_BRANCH" scripts/ci/libraries/_initialization.sh | \
@@ -218,7 +218,7 @@ jobs:
     strategy:
       matrix:
         # We need to attempt to build all possible versions here because pull_request_target
-        # event is run from master for both master and v1-10-tests
+        # event is run for both main and v1-10-tests
         python-version: ${{ fromJson(needs.build-info.outputs.allPythonVersions) }}
       fail-fast: true
     if: needs.build-info.outputs.image-build == 'true'
@@ -245,7 +245,7 @@ jobs:
         # We cannot "source" the script here because that would be a security problem (we cannot run
         # any code that comes from the sources coming from the PR. Therefore we extract the
         # DEFAULT_BRANCH and DEFAULT_CONSTRAINTS_BRANCH via custom grep/awk/sed commands
-        # Also 2.7 and 3.5 versions are not allowed to proceed on master
+        # Also 2.7 and 3.5 versions are not allowed to proceed on main
         id: defaults
         run: |
           DEFAULT_BRANCH=$(grep "export DEFAULT_BRANCH" scripts/ci/libraries/_initialization.sh | \

.github/workflows/ci.yml

@@ -21,9 +21,9 @@ on:  # yamllint disable-line rule:truthy
   schedule:
     - cron: '28 0 * * *'
   push:
-    branches: ['master', 'v[0-9]+-[0-9]+-test']
+    branches: ['main', 'v[0-9]+-[0-9]+-test']
   pull_request:
-    branches: ['master', 'v[0-9]+-[0-9]+-test', 'v[0-9]+-[0-9]+-stable']
+    branches: ['main', 'v[0-9]+-[0-9]+-test', 'v[0-9]+-[0-9]+-stable']
 
 env:
   MOUNT_SELECTED_LOCAL_SOURCES: "false"
@@ -496,15 +496,15 @@ ${{ hashFiles('.pre-commit-config.yaml') }}"
       - name: Configure AWS credentials
         uses: ./.github/actions/configure-aws-credentials
         if: >
-          github.ref == 'refs/heads/master' && github.repository == 'apache/airflow' &&
+          github.ref == 'refs/heads/main' && github.repository == 'apache/airflow' &&
           github.event_name == 'push'
         with:
           aws-access-key-id: ${{ secrets.DOCS_AWS_ACCESS_KEY_ID }}
           aws-secret-access-key: ${{ secrets.DOCS_AWS_SECRET_ACCESS_KEY }}
           aws-region: eu-central-1
       - name: "Upload documentation to AWS S3"
         if: >
-          github.ref == 'refs/heads/master' && github.repository == 'apache/airflow' &&
+          github.ref == 'refs/heads/main' && github.repository == 'apache/airflow' &&
           github.event_name == 'push'
         run: aws s3 sync --delete ./files/documentation s3://apache-airflow-docs
 
@@ -519,13 +519,13 @@ ${{ hashFiles('.pre-commit-config.yaml') }}"
       PYTHON_MAJOR_MINOR_VERSION: ${{needs.build-info.outputs.defaultPythonVersion}}
       VERSION_SUFFIX_FOR_PYPI: ".dev0"
       GITHUB_REGISTRY: ${{ needs.ci-images.outputs.githubRegistry }}
-    if: needs.build-info.outputs.image-build == 'true' && needs.build-info.outputs.default-branch == 'master'
+    if: needs.build-info.outputs.image-build == 'true' && needs.build-info.outputs.default-branch == 'main'
     steps:
       - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
         uses: actions/checkout@v2
         with:
           persist-credentials: false
-        if: needs.build-info.outputs.default-branch == 'master'
+        if: needs.build-info.outputs.default-branch == 'main'
       - name: "Setup python"
         uses: actions/setup-python@v2
         with:
@@ -566,13 +566,13 @@ ${{ hashFiles('.pre-commit-config.yaml') }}"
       PYTHON_MAJOR_MINOR_VERSION: ${{needs.build-info.outputs.defaultPythonVersion}}
       VERSION_SUFFIX_FOR_PYPI: ".dev0"
       GITHUB_REGISTRY: ${{ needs.ci-images.outputs.githubRegistry }}
-    if: needs.build-info.outputs.image-build == 'true' && needs.build-info.outputs.default-branch == 'master'
+    if: needs.build-info.outputs.image-build == 'true' && needs.build-info.outputs.default-branch == 'main'
     steps:
       - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
         uses: actions/checkout@v2
         with:
           persist-credentials: false
-        if: needs.build-info.outputs.default-branch == 'master'
+        if: needs.build-info.outputs.default-branch == 'main'
       - name: "Setup python"
         uses: actions/setup-python@v2
         with:
@@ -897,8 +897,8 @@ ${{ hashFiles('.pre-commit-config.yaml') }}"
         uses: actions/setup-python@v2
         with:
           python-version: ${{ env.PYTHON_MAJOR_MINOR_VERSION }}
-      - name: "Set issue id for master"
-        if: github.ref == 'refs/heads/master'
+      - name: "Set issue id for main"
+        if: github.ref == 'refs/heads/main'
         run: |
           echo "ISSUE_ID=10118" >> $GITHUB_ENV
       - name: "Set issue id for v1-10-stable"
@@ -1109,7 +1109,7 @@ ${{ hashFiles('.pre-commit-config.yaml') }}"
       - docs
     # TODO: Generalize me (find a better way to select matching branches)
     if: >
-      (github.ref == 'refs/heads/master' || github.ref == 'refs/heads/v1-10-test' ||
+      (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/v1-10-test' ||
       github.ref == 'refs/heads/v2-0-test' || github.ref == 'refs/heads/v2-1-test') &&
       github.event_name != 'schedule'
     strategy:
@@ -1134,7 +1134,7 @@ ${{ hashFiles('.pre-commit-config.yaml') }}"
       - name: Set push-python-image
         id: push-python-image
         run: |
-          if [[ "${REF}" == 'refs/head/master' || "${REF}" == 'refs/head/main' ]]; then
+          if [[ "${REF}" == 'refs/head/main' || "${REF}" == 'refs/head/main' ]]; then
               echo "::set-output name=wanted::true"
           else
               echo "::set-output name=wanted::false"
@@ -1171,7 +1171,7 @@ ${{ hashFiles('.pre-commit-config.yaml') }}"
       - docs
     # TODO: Generalize me (find a better way to select matching branches)
     if: >
-      (github.ref == 'refs/heads/master' || github.ref == 'refs/heads/v1-10-test' ||
+      (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/v1-10-test' ||
       github.ref == 'refs/heads/v2-0-test' || github.ref == 'refs/heads/v2-1-test') &&
       github.event_name != 'schedule'
     strategy:
@@ -1221,7 +1221,7 @@ ${{ hashFiles('.pre-commit-config.yaml') }}"
     # Only run it for direct pushes
     # TODO: Generalize me (find a better way to select matching branches)
     if: >
-      github.ref == 'refs/heads/master' || github.ref == 'refs/heads/v1-10-test' ||
+      github.ref == 'refs/heads/main' || github.ref == 'refs/heads/v1-10-test' ||
       github.ref == 'refs/heads/v2-0-test' || github.ref == 'refs/heads/v2-1-test'
     steps:
       - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
@@ -1308,7 +1308,7 @@ ${{ hashFiles('.pre-commit-config.yaml') }}"
           github_token: ${{ secrets.GITHUB_TOKEN }}
           tags: true
           force: true
-          branch: master
+          branch: main
 
   tests-ui:
     timeout-minutes: 10

.github/workflows/codeql-analysis.yml

@@ -20,7 +20,7 @@ name: "CodeQL"
 
 on:  # yamllint disable-line rule:truthy
   push:
-    branches: [master, main]
+    branches: [main]
   schedule:
     - cron: '0 2 * * *'
 

.github/workflows/label_when_reviewed_workflow_run.yml

@@ -72,7 +72,7 @@ jobs:
           ref: ${{ steps.source-run-info.outputs.targetCommitSha }}
           fetch-depth: 2
           persist-credentials: false
-      # checkout the master version again, to use the right script in master workflow
+      # checkout the main branch again, to use the right script in main workflow
       - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
         uses: actions/checkout@v2
         with:
@@ -107,7 +107,7 @@ jobs:
           comment: >
             The PR most likely needs to run full matrix of tests because it modifies parts of the core
             of Airflow. However, committers might decide to merge it quickly and take the risk.
-            If they don't merge it quickly - please rebase it to the latest master at your convenience,
+            If they don't merge it quickly - please rebase it to the latest main at your convenience,
             or amend the last commit of the PR, and push it with --force-with-lease.
       - name: "Initiate GitHub Check forcing rerun of SH ${{ github.event.pull_request.head.sha }}"
         uses: ./.github/actions/checks-action
@@ -139,7 +139,7 @@ jobs:
             The PR is likely OK to be merged with just subset of tests for default Python and Database
             versions without running the full matrix of tests, because it does not modify the core of
             Airflow. If the committers decide that the full tests matrix is needed, they will add the label
-            'full tests needed'. Then you should rebase to the latest master or amend the last commit
+            'full tests needed'. Then you should rebase to the latest main or amend the last commit
             of the PR, and push it with --force-with-lease.
       - name: "Label when approved by committers for PRs that do not require tests at all"
         uses: ./.github/actions/label-when-approved-action
@@ -153,7 +153,7 @@ jobs:
           comment: >
             The PR is likely ready to be merged. No tests are needed as no important environment files,
             nor python files were modified by it. However, committers might decide that full test matrix is
-            needed and add the 'full tests needed' label. Then you should rebase it to the latest master
+            needed and add the 'full tests needed' label. Then you should rebase it to the latest main
             or amend the last commit of the PR, and push it with --force-with-lease.
       - name: Update Selective Build check
         uses: ./.github/actions/checks-action