Add CI for testnode that starts up nitro test node and rans l2 transactions

.github/workflows/ci.yml

@@ -0,0 +1,37 @@
+name: CI
+run-name: CI triggered from @${{ github.actor }} of ${{ github.head_ref }}
+
+on:
+    workflow_dispatch:
+    merge_group:
+    pull_request:
+    push:
+      branches:
+        - master
+        - develop
+
+
+jobs:
+  build_and_run:
+    runs-on: ubuntu-8
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+      with:
+        submodules: recursive
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v3
+      with:
+        driver-opts: network=host
+
+    - name: Cache Docker layers
+      uses: actions/cache@v3
+      with:
+        path: /tmp/.buildx-cache
+        key: ${{ runner.os }}-buildx-${{ hashFiles('Dockerfile') }}
+        restore-keys: ${{ runner.os }}-buildx-
+
+    - name:  Startup Nitro testnode
+      run: ${{ github.workspace }}/.github/workflows/testnode.bash

.github/workflows/testnode.bash

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+#!/bin/bash
+# The script starts up the test node and waits until the timeout (10min) or 
+# until send-l2 succeeds.
+
+# Start the test node and get PID, to terminate it once send-l2 is done.
+${GITHUB_WORKSPACE}/test-node.bash --init > output.log 2>&1 &
+PID=$!
+
+sleep 5m
+
+START=$(date +%s)
+SUCCEDED=0
+
+while true; do
+    if ${GITHUB_WORKSPACE}/test-node.bash script send-l2 --ethamount 100 --to user_l2user --wait; then
+        echo "Sending l2 transaction succeeded"
+        SUCCEDED=1
+        break
+    fi
+
+    # Check if the timeout (10 min) has been reached.
+    NOW=$(date +%s)
+    DIFF=$((NOW - START))
+    if [ "$DIFF" -ge 600 ]; then
+        echo "Timed out"
+        break
+    fi
+
+    sleep 10
+done
+
+# Shut down the test node and wait for it to terminate.
+kill $PID
+wait $PID
+
+if [ "$SUCCEDED" -eq 0 ]; then
+    exit 1
+fi
+
+exit 0