Add manual e2e workflow to v0.34.x. (#8005)

.github/workflows/e2e-manual.yml

@@ -0,0 +1,35 @@
+# Manually run randomly generated E2E testnets (as nightly).
+name: e2e-manual
+on:
+  workflow_dispatch:
+
+jobs:
+  e2e-nightly-test:
+    # Run parallel jobs for the listed testnet groups (must match the
+    # ./build/generator -g flag)
+    strategy:
+      fail-fast: false
+      matrix:
+        group: ['00', '01', '02', '03']
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+    steps:
+      - uses: actions/setup-go@v2
+        with:
+          go-version: '1.17'
+
+      - uses: actions/checkout@v2.4.0
+
+      - name: Build
+        working-directory: test/e2e
+        # Run make jobs in parallel, since we can't run steps in parallel.
+        run: make -j2 docker generator runner tests
+
+      - name: Generate testnets
+        working-directory: test/e2e
+        # When changing -g, also change the matrix groups above
+        run: ./build/generator -g 4 -d networks/nightly/
+
+      - name: Run ${{ matrix.p2p }} p2p testnets
+        working-directory: test/e2e
+        run: ./run-multiple.sh networks/nightly/*-group${{ matrix.group }}-*.toml