From 586cf18b8d7c3baaca4164cebe0e392d9972bdbd Mon Sep 17 00:00:00 2001
From: Vincent Koc <vincentkoc@ieee.org>
Date: Sun, 7 Jun 2026 05:30:00 +0200
Subject: [PATCH] fix(e2e): bound docker log printing

---
 scripts/lib/docker-e2e-logs.sh           | 22 +++++++++++++++++-
 test/scripts/docker-build-helper.test.ts | 29 ++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/scripts/lib/docker-e2e-logs.sh b/scripts/lib/docker-e2e-logs.sh
index 3d5f839b0b21..fb8882b9d5ed 100644
--- a/scripts/lib/docker-e2e-logs.sh
+++ b/scripts/lib/docker-e2e-logs.sh
@@ -78,5 +78,25 @@ docker_e2e_run_log() {
 
 docker_e2e_print_log() {
   local log_file="$1"
-  cat "$log_file"
+  local max_bytes="${OPENCLAW_DOCKER_E2E_LOG_PRINT_BYTES:-65536}"
+  if ! [[ "$max_bytes" =~ ^[0-9]+$ ]] || [ "$max_bytes" -lt 1 ]; then
+    max_bytes="65536"
+  else
+    max_bytes="$((10#$max_bytes))"
+  fi
+  if [ ! -f "$log_file" ]; then
+    return 0
+  fi
+  local log_bytes
+  log_bytes="$(wc -c <"$log_file" 2>/dev/null || echo 0)"
+  log_bytes="${log_bytes//[[:space:]]/}"
+  if ! [[ "$log_bytes" =~ ^[0-9]+$ ]]; then
+    log_bytes="0"
+  fi
+  if [ "$log_bytes" -le "$max_bytes" ]; then
+    cat "$log_file"
+    return 0
+  fi
+  echo "--- ${log_file} truncated: showing last ${max_bytes} of ${log_bytes} bytes ---"
+  tail -c "$max_bytes" "$log_file"
 }
diff --git a/test/scripts/docker-build-helper.test.ts b/test/scripts/docker-build-helper.test.ts
index b5756b20e138..a71bb8089d15 100644
--- a/test/scripts/docker-build-helper.test.ts
+++ b/test/scripts/docker-build-helper.test.ts
@@ -1818,10 +1818,39 @@ test -f "$TMPDIR/docker-cmd-seen"
     expect(helper).toContain("docker_e2e_run_logged_print_with_harness()");
     expect(helper).toContain("run_logged_print_heartbeat \\");
     expect(helper).toContain("OPENCLAW_DOCKER_E2E_LOG_HEARTBEAT_SECONDS");
+    expect(readFileSync("scripts/lib/docker-e2e-logs.sh", "utf8")).toContain(
+      "OPENCLAW_DOCKER_E2E_LOG_PRINT_BYTES",
+    );
     expect(runner).toContain("docker_e2e_run_logged_print_with_harness \\");
     expect(runner).not.toContain("docker_e2e_run_logged_with_harness plugins-run");
   });
 
+  it("bounds printed Docker E2E logs to the configured tail", () => {
+    const workDir = mkdtempSync(join(tmpdir(), "openclaw-docker-e2e-log-print-tail-"));
+
+    try {
+      const rootDir = process.cwd();
+      const script = `
+set -euo pipefail
+ROOT_DIR=${shellQuote(rootDir)}
+TMPDIR=${shellQuote(workDir)}
+export ROOT_DIR TMPDIR
+export OPENCLAW_DOCKER_E2E_LOG_PRINT_BYTES=64
+
+source "$ROOT_DIR/scripts/lib/docker-e2e-logs.sh"
+
+output="$(run_logged_print_heartbeat plugins-run 30 bash -c 'printf "DO_NOT_PRINT_OLD_LOG_START"; printf "%0200d" 0; printf "recent container log tail\\\\n"')"
+[[ "$output" = *"truncated: showing last 64"* ]]
+[[ "$output" = *"recent container log tail"* ]]
+[[ "$output" != *"DO_NOT_PRINT_OLD_LOG_START"* ]]
+`;
+
+      execFileSync("bash", ["-lc", script], { encoding: "utf8" });
+    } finally {
+      rmSync(workDir, { recursive: true, force: true });
+    }
+  });
+
   it("prints heartbeat progress for long successful Docker E2E log captures", () => {
     const workDir = mkdtempSync(join(tmpdir(), "openclaw-docker-e2e-log-heartbeat-"));