diff --git a/.github/workflows/build-images-workflow-run.yml b/.github/workflows/build-images-workflow-run.yml
index 3e96d4f5366..1da0a742299 100644
--- a/.github/workflows/build-images-workflow-run.yml
+++ b/.github/workflows/build-images-workflow-run.yml
@@ -45,7 +45,7 @@ jobs:
   cancel-workflow-runs:
     timeout-minutes: 10
     name: "Cancel workflow runs"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     outputs:
       sourceHeadRepo: ${{ steps.source-run-info.outputs.sourceHeadRepo }}
       sourceHeadBranch: ${{ steps.source-run-info.outputs.sourceHeadBranch }}
@@ -193,7 +193,7 @@ jobs:
       Source Sha: ${{ needs.cancel-workflow-runs.outputs.sourceHeadSha }}
       Merge commit Sha: ${{ needs.cancel-workflow-runs.outputs.mergeCommitSha }}
       Target commit Sha: ${{ needs.cancel-workflow-runs.outputs.targetCommitSha }}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [cancel-workflow-runs]
     env:
       GITHUB_CONTEXT: ${{ toJson(github) }}
@@ -248,7 +248,7 @@ jobs:
   build-images:
     timeout-minutes: 80
     name: "Build ${{matrix.image-type}} images ${{matrix.python-version}}"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, cancel-workflow-runs]
     strategy:
       matrix:
@@ -374,7 +374,7 @@ jobs:
 
   cancel-on-build-cancel:
     name: "Cancel 'CI Build' jobs on build image cancelling."
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     if: cancelled()
     needs: [build-images]
     steps:
@@ -389,7 +389,7 @@ jobs:
 
   cancel-on-build-failure:
     name: "Cancel 'CI Build' jobs on build image failing."
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     if: failure()
     needs: [build-images]
     steps:
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 94934f39c19..175a6b0b546 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -65,7 +65,7 @@ jobs:
 
   build-info:
     name: "Build info"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     env:
       GITHUB_CONTEXT: ${{ toJson(github) }}
     outputs:
@@ -147,7 +147,7 @@ jobs:
 
   test-openapi-client-generation:
     name: "Test OpenAPI client generation"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info]
     if: needs.build-info.outputs.needs-api-codegen == 'true'
     steps:
@@ -161,7 +161,7 @@ jobs:
   ci-images:
     timeout-minutes: 120
     name: "Wait for CI images"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info]
     if: needs.build-info.outputs.image-build == 'true'
     env:
@@ -195,7 +195,7 @@ jobs:
   static-checks:
     timeout-minutes: 30
     name: "Static checks"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, ci-images]
     env:
       SKIP: "pylint"
@@ -231,7 +231,7 @@ jobs:
   static-checks-basic-checks-only:
     timeout-minutes: 30
     name: "Static checks: basic checks only"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info]
     env:
       SKIP: "build,mypy,flake8,pylint,bats-in-container-tests"
@@ -268,7 +268,7 @@ jobs:
   static-checks-pylint:
     timeout-minutes: 30
     name: "Pylint"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, ci-images]
     if: needs.build-info.outputs.basic-checks-only == 'false'
     env:
@@ -302,7 +302,7 @@ jobs:
   docs:
     timeout-minutes: 30
     name: "Build docs"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, ci-images]
     if: needs.build-info.outputs.docs-build == 'true'
     steps:
@@ -322,7 +322,7 @@ jobs:
   docs-spell-check:
     timeout-minutes: 30
     name: "Spell check docs"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, ci-images]
     env:
       PYTHON_MAJOR_MINOR_VERSION: ${{needs.build-info.outputs.defaultPythonVersion}}
@@ -338,7 +338,7 @@ jobs:
   prepare-backport-provider-packages:
     timeout-minutes: 30
     name: "Backport packages"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, ci-images]
     env:
       INSTALL_AIRFLOW_VERSION: "1.10.12"
@@ -375,7 +375,7 @@ jobs:
   prepare-provider-packages:
     timeout-minutes: 30
     name: "Provider packages"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, ci-images]
     env:
       INSTALL_AIRFLOW_VERSION: "wheel"
@@ -412,7 +412,7 @@ jobs:
   tests-helm:
     timeout-minutes: 20
     name: "Python unit tests for helm chart"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, ci-images]
     env:
       MOUNT_LOCAL_SOURCES: "true"
@@ -460,7 +460,7 @@ jobs:
     name: >
       Postgres${{matrix.postgres-version}},Py${{matrix.python-version}}:
       ${{needs.build-info.outputs.testTypes}}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, ci-images]
     strategy:
       matrix:
@@ -512,7 +512,7 @@ jobs:
     timeout-minutes: 80
     name: >
       MySQL${{matrix.mysql-version}}, Py${{matrix.python-version}}: ${{needs.build-info.outputs.testTypes}}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, ci-images]
     strategy:
       matrix:
@@ -563,7 +563,7 @@ jobs:
     timeout-minutes: 60
     name: >
       Sqlite Py${{matrix.python-version}}: ${{needs.build-info.outputs.testTypes}}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, ci-images]
     strategy:
       matrix:
@@ -611,7 +611,7 @@ jobs:
   tests-quarantined:
     timeout-minutes: 60
     name: "Quarantined tests"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     continue-on-error: true
     needs: [build-info, ci-images]
     strategy:
@@ -683,7 +683,7 @@ jobs:
   upload-coverage:
     timeout-minutes: 5
     name: "Upload coverage"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     continue-on-error: true
     needs:
       - tests-kubernetes
@@ -706,7 +706,7 @@ jobs:
   prod-images:
     timeout-minutes: 120
     name: "Wait for PROD images"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info]
     env:
       BACKEND: sqlite
@@ -736,7 +736,7 @@ jobs:
   tests-kubernetes:
     timeout-minutes: 50
     name: K8s ${{matrix.python-version}} ${{matrix.kubernetes-version}} ${{matrix.kubernetes-mode}}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [build-info, prod-images]
     strategy:
       matrix:
@@ -811,7 +811,7 @@ jobs:
   push-prod-images-to-github-registry:
     timeout-minutes: 10
     name: "Push PROD images"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs:
       - build-info
       - static-checks
@@ -851,7 +851,7 @@ jobs:
   push-ci-images-to-github-registry:
     timeout-minutes: 10
     name: "Push CI images"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs:
       - build-info
       - static-checks
@@ -890,7 +890,7 @@ jobs:
   constraints:
     timeout-minutes: 10
     name: "Constraints"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     strategy:
       matrix:
         python-version: ${{ fromJson(needs.build-info.outputs.pythonVersions) }}
@@ -923,7 +923,7 @@ jobs:
   constraints-push:
     timeout-minutes: 10
     name: "Constraints push"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs:
       - build-info
       - constraints
@@ -961,7 +961,7 @@ jobs:
   tag-repo-nightly:
     timeout-minutes: 10
     name: "Tag repo nightly"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs:
       - docs
       - docs-spell-check
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index e0178bf3be0..2bf92b788af 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -27,7 +27,7 @@ on:  # yamllint disable-line rule:truthy
 jobs:
   selective-checks:
     name: Selective checks
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     outputs:
       needs-python-scans: ${{ steps.selective-checks.outputs.needs-python-scans }}
       needs-javascript-scans: ${{ steps.selective-checks.outputs.needs-javascript-scans }}
@@ -52,7 +52,7 @@ jobs:
 
   analyze:
     name: Analyze
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [selective-checks]
     strategy:
       fail-fast: false
diff --git a/.github/workflows/delete_old_artifacts.yml b/.github/workflows/delete_old_artifacts.yml
index 8b3571196b6..98329d5d642 100644
--- a/.github/workflows/delete_old_artifacts.yml
+++ b/.github/workflows/delete_old_artifacts.yml
@@ -23,7 +23,7 @@ on:  # yamllint disable-line rule:truthy
 
 jobs:
   delete-artifacts:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: kolpav/purge-artifacts-action@04c636a505f26ebc82f8d070b202fb87ff572b10  # v1.0
         with:
diff --git a/.github/workflows/label_when_reviewed.yml b/.github/workflows/label_when_reviewed.yml
index 62d7cc642fc..5095953def1 100644
--- a/.github/workflows/label_when_reviewed.yml
+++ b/.github/workflows/label_when_reviewed.yml
@@ -23,7 +23,7 @@ jobs:
 
   label-when-reviewed:
     name: "Label PRs when reviewed"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: "Do nothing. Only trigger corresponding workflow_run event"
         run: echo
diff --git a/.github/workflows/label_when_reviewed_workflow_run.yml b/.github/workflows/label_when_reviewed_workflow_run.yml
index f943609a8d2..6e450383956 100644
--- a/.github/workflows/label_when_reviewed_workflow_run.yml
+++ b/.github/workflows/label_when_reviewed_workflow_run.yml
@@ -25,7 +25,7 @@ jobs:
 
   label-when-reviewed:
     name: "Label PRs when reviewed workflow run"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     outputs:
       labelSet: ${{ steps.label-when-reviewed.outputs.labelSet }}
     steps:
diff --git a/.github/workflows/repo_sync.yml b/.github/workflows/repo_sync.yml
index 4d1646ad518..5df2e9113d4 100644
--- a/.github/workflows/repo_sync.yml
+++ b/.github/workflows/repo_sync.yml
@@ -22,7 +22,7 @@ on:  # yamllint disable-line rule:truthy
 jobs:
   repo-sync:
     if: github.repository != 'apache/airflow'
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@master
       - name: repo-sync
diff --git a/.github/workflows/scheduled_quarantined.yml b/.github/workflows/scheduled_quarantined.yml
index 552edfbc242..cf29c38f926 100644
--- a/.github/workflows/scheduled_quarantined.yml
+++ b/.github/workflows/scheduled_quarantined.yml
@@ -48,7 +48,7 @@ jobs:
   trigger-tests:
     timeout-minutes: 5
     name: "Checks if tests should be run"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     outputs:
       run-tests: ${{ steps.trigger-tests.outputs.run-tests }}
     steps:
@@ -60,7 +60,7 @@ jobs:
   tests-quarantined:
     timeout-minutes: 80
     name: "Quarantined tests"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     continue-on-error: true
     needs: [trigger-tests]
     strategy: