workflows: Skip jobs instead of workflows

.github/workflows/documentation.yaml

@@ -2,33 +2,41 @@ name: Documentation Updates
 
 # Any change in triggers needs to be reflected in the concurrency group.
 on:
-  pull_request:
-    paths:
-      - 'Documentation/**'
-      - 'bugtool/cmd/**'
-      - 'cilium/cmd/**'
-      - 'cilium-health/cmd/**'
-      - 'daemon/cmd/**'
-      - 'hubble-relay/cmd/**'
-      - 'operator/cmd/**'
+  pull_request: {}
   push:
     branches:
       - master
-    paths:
-      - 'Documentation/**'
-      - 'bugtool/cmd/**'
-      - 'cilium/cmd/**'
-      - 'cilium-health/cmd/**'
-      - 'daemon/cmd/**'
-      - 'hubble-relay/cmd/**'
-      - 'operator/cmd/**'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.event.after }}
   cancel-in-progress: true
 
 jobs:
+  check_changes:
+    name: Deduce required tests from code changes
+    runs-on: ubuntu-18.04
+    outputs:
+      docs-tree: ${{ steps.docs-tree.outputs.src }}
+    steps:
+      - name: Check code changes
+        uses: dorny/paths-filter@78ab00f87740f82aec8ed8826eb4c3c851044126
+        id: docs-tree
+        with:
+          filters: |
+            src:
+              - 'Documentation/**'
+              - 'bugtool/cmd/**'
+              - 'cilium/cmd/**'
+              - 'cilium-health/cmd/**'
+              - 'daemon/cmd/**'
+              - 'hubble-relay/cmd/**'
+              - 'operator/cmd/**'
+
+  # Runs only if code under Documentation or */cmd/ is changed as the docs
+  # should be unaffected otherwise.
   build-html:
+    needs: check_changes
+    if: ${{ needs.check_changes.outputs.docs-tree == 'true' }}
     name: Validate & Build HTML
     runs-on: ubuntu-18.04
     steps:

.github/workflows/lint-codeql.yaml

@@ -1,22 +1,31 @@
 name: codeql
 
 on:
-  push:
-    paths:
-      - '*.go'
-      - 'go.mod'
-      - 'go.sum'
-  pull_request:
-    paths:
-      - '*.go'
-      - 'go.mod'
-      - 'go.sum'
+  push: {}
+  pull_request: {}
   schedule:
     - cron: "45 6 * * 3"
 
 jobs:
+  check_changes:
+    name: Deduce required tests from code changes
+    runs-on: ubuntu-18.04
+    outputs:
+      go-changes: ${{ steps.go-changes.outputs.src }}
+    steps:
+      - name: Check code changes
+        uses: dorny/paths-filter@78ab00f87740f82aec8ed8826eb4c3c851044126
+        id: go-changes
+        with:
+          filters: |
+            src:
+              - '*.go'
+              - 'go.mod'
+              - 'go.sum'
+
   analyze:
-    if: github.repository == 'cilium/cilium'
+    needs: check_changes
+    if: github.repository == 'cilium/cilium' && needs.check_changes.outputs.go-changes == 'true'
     runs-on: ubuntu-18.04
     steps:
     - name: Checkout repo

.github/workflows/tests-smoke-ipv6.yaml

@@ -2,16 +2,10 @@ name: Smoke Test with IPv6
 
 # Any change in triggers needs to be reflected in the concurrency group.
 on:
-  pull_request:
-    paths-ignore:
-      - 'Documentation/**'
-      - 'test/**'
+  pull_request: {}
   push:
     branches:
       - master
-    paths-ignore:
-      - 'Documentation/**'
-      - 'test/**'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.event.after }}
@@ -26,8 +20,23 @@ env:
   LOG_TIME: 30m
 
 jobs:
+  check_changes:
+    name: Deduce required tests from code changes
+    runs-on: ubuntu-18.04
+    outputs:
+      tested: ${{ steps.tested-tree.outputs.src }}
+    steps:
+      - name: Check code changes
+        uses: dorny/paths-filter@78ab00f87740f82aec8ed8826eb4c3c851044126
+        id: tested-tree
+        with:
+          filters: |
+            src:
+              - '!(test|Documentation)/**'
+
   conformance-test-ipv6:
-    if: ${{ github.repository == 'cilium/cilium' }}
+    needs: check_changes
+    if: ${{ github.repository == 'cilium/cilium' && needs.check_changes.outputs.tested == 'true' }}
     runs-on: ubuntu-latest
     steps:
       - name: Checkout

.github/workflows/tests-smoke.yaml

@@ -2,16 +2,10 @@ name: Smoke test
 
 # Any change in triggers needs to be reflected in the concurrency group.
 on:
-  pull_request:
-    paths-ignore:
-      - 'Documentation/**'
-      - 'test/**'
+  pull_request: {}
   push:
     branches:
       - master
-    paths-ignore:
-      - 'Documentation/**'
-      - 'test/**'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.event.after }}
@@ -25,6 +19,20 @@ env:
   LOG_TIME: 30m
 
 jobs:
+  check_changes:
+    name: Deduce required tests from code changes
+    runs-on: ubuntu-18.04
+    outputs:
+      tested: ${{ steps.tested-tree.outputs.src }}
+    steps:
+      - name: Check code changes
+        uses: dorny/paths-filter@78ab00f87740f82aec8ed8826eb4c3c851044126
+        id: tested-tree
+        with:
+          filters: |
+            src:
+              - '!(test|Documentation)/**'
+
   preflight-clusterrole:
     runs-on: ubuntu-latest
     steps:
@@ -69,7 +77,8 @@ jobs:
           git diff --exit-code || (echo "please run 'make -C install/kubernetes docs' and submit your changes"; exit 1)
 
   conformance-test:
-    if: ${{ github.repository == 'cilium/cilium' }}
+    needs: check_changes
+    if: ${{ github.repository == 'cilium/cilium' && needs.check_changes.outputs.tested == 'true' }}
     runs-on: ubuntu-latest
     steps:
       - name: Checkout