diff --git a/Jenkinsfile b/Jenkinsfile
index 772dfab..dd4f2bc 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -40,10 +40,10 @@ pipeline {
       steps {
         withEnv(["PYTHON_BASE_IMAGE=${params.PYTHON_BASE_IMAGE}", "DEBIAN_MIRROR=${params.DEBIAN_MIRROR ?: 'https://deb.debian.org'}"]) {
           sh '''set -eu
-            docker build --target test --build-arg PYTHON_BASE_IMAGE="$PYTHON_BASE_IMAGE" --build-arg DEBIAN_MIRROR="$DEBIAN_MIRROR" -t "$CHAT_IMAGE-test" .
-            docker build --target production --build-arg PYTHON_BASE_IMAGE="$PYTHON_BASE_IMAGE" --build-arg DEBIAN_MIRROR="$DEBIAN_MIRROR" \
+            sh deploy/build-image.sh --target test --build-arg PYTHON_BASE_IMAGE="$PYTHON_BASE_IMAGE" --build-arg DEBIAN_MIRROR="$DEBIAN_MIRROR" -t "$CHAT_IMAGE-test" .
+            sh deploy/build-image.sh --target production --build-arg PYTHON_BASE_IMAGE="$PYTHON_BASE_IMAGE" --build-arg DEBIAN_MIRROR="$DEBIAN_MIRROR" \
               --label "org.opencontainers.image.revision=$SOURCE_COMMIT" -t "$CHAT_IMAGE" .
-            docker build --target certbot --build-arg PYTHON_BASE_IMAGE="$PYTHON_BASE_IMAGE" --build-arg DEBIAN_MIRROR="$DEBIAN_MIRROR" \
+            sh deploy/build-image.sh --target certbot --build-arg PYTHON_BASE_IMAGE="$PYTHON_BASE_IMAGE" --build-arg DEBIAN_MIRROR="$DEBIAN_MIRROR" \
               --label "org.opencontainers.image.revision=$SOURCE_COMMIT" -t "$CERTBOT_IMAGE" .
           '''
         }
diff --git a/deploy/build-image.sh b/deploy/build-image.sh
new file mode 100644
index 0000000..a617456
--- /dev/null
+++ b/deploy/build-image.sh
@@ -0,0 +1,18 @@
+#!/bin/sh
+set -eu
+
+# 构建前至少保留 1GiB 给业务服务，避免在宿主机内存不足时继续启动构建。
+available_kib=$(awk '$1 == "MemAvailable:" { print $2 }' /proc/meminfo)
+case "$available_kib" in
+  ''|*[!0-9]*) echo 'Cannot read host available memory; build refused.' >&2; exit 69 ;;
+esac
+if [ "$available_kib" -lt 4194304 ]; then
+  echo 'Docker build requires at least 4GiB available host memory; retry after resources recover.' >&2
+  exit 75
+fi
+
+# 当前节点使用 Docker 26 的经典构建器。显式固定后端，确保资源参数实际生效。
+# 限制覆盖每个 RUN 容器，失败时也清理中间容器，超时由宿主机独立终止。
+exec env DOCKER_BUILDKIT=0 timeout --signal=TERM --kill-after=30s 15m \
+  docker build --memory=3g --memory-swap=3g \
+  --cpu-period=100000 --cpu-quota=200000 --force-rm "$@"
diff --git a/docs/deployment.md b/docs/deployment.md
index 0cd26b7..3a9bc04 100644
--- a/docs/deployment.md
+++ b/docs/deployment.md
@@ -14,6 +14,8 @@
 
 `java-builder` 标签代理须有 Docker、Bash、Python 3、Node.js 18+、OpenSSL、SSH，并能下载所选 Python 基础镜像和 PyPI 依赖。标签不表示固定物理节点。
 
+三个镜像目标均通过 `deploy/build-image.sh` 构建。当前 Docker 26 节点显式使用经典构建器，每个构建容器限制为 3GiB 内存及内存/交换总额、2 CPU；宿主机可用内存不足 4GiB 或无法读取时拒绝启动。单次构建由 GNU timeout 限制为 15 分钟，TERM 后 30 秒强制终止，流水线总上限仍为 30 分钟。正常构建失败也移除中间容器；服务器重启留下的退出容器只占磁盘。构建节点保持单执行器，须提供 GNU timeout 和 awk，切换构建后端时重新验证硬限制。离线回归使用 `node --test tests/frontend/build_resources.test.cjs`。
+
 以下参数由私有灰度配置提供，实际地址和凭据值不写入源码：
 
 | 参数 | 含义 |
diff --git a/tests/frontend/build_resources.test.cjs b/tests/frontend/build_resources.test.cjs
new file mode 100644
index 0000000..c383263
--- /dev/null
+++ b/tests/frontend/build_resources.test.cjs
@@ -0,0 +1,61 @@
+const assert = require('node:assert/strict')
+const { existsSync, mkdtempSync, readFileSync, rmSync, writeFileSync } = require('node:fs')
+const { tmpdir } = require('node:os')
+const { dirname, join, resolve } = require('node:path')
+const { spawnSync } = require('node:child_process')
+const test = require('node:test')
+
+const root = resolve(__dirname, '../..')
+const wrapper = join(root, 'deploy/build-image.sh')
+const bash = process.platform === 'win32' ? 'C:/Program Files/Git/bin/bash.exe' : 'bash'
+const shellAvailable = process.platform !== 'win32' || existsSync(bash)
+
+// 使用替身验证参数、内存预检和退出码，不启动 Docker 或访问部署环境。
+function runBuild(availableMemory, childStatus = '0') {
+  const directory = mkdtempSync(join(tmpdir(), 'frontend-build-resource-'))
+  try {
+    writeFileSync(join(directory, 'awk'), '#!/bin/sh\nprintf "%s\\n" "$TEST_AVAILABLE_MEMORY"\n', { mode: 0o755 })
+    writeFileSync(join(directory, 'timeout'), '#!/bin/sh\nprintf "%s\\n" watchdog "$@"\nshift 3\nexec "$@"\n', { mode: 0o755 })
+    writeFileSync(join(directory, 'docker'), '#!/bin/sh\nprintf "%s\\n" "builder=$DOCKER_BUILDKIT" "$@"\nexit "$TEST_CHILD_STATUS"\n', { mode: 0o755 })
+    return spawnSync(bash, ['-c',
+      'testbin=$(cd "$1" && pwd); shift; PATH="$testbin:$PATH"; export PATH; exec sh "$@"',
+      'fixture', directory.replaceAll('\\', '/'), wrapper.replaceAll('\\', '/'),
+      '--build-arg', 'VALUE=with space', '-t', 'web:test', '.'], {
+      encoding: 'utf8', timeout: 10000,
+      env: { ...process.env, DOCKER_BUILDKIT: '1', TEST_AVAILABLE_MEMORY: availableMemory, TEST_CHILD_STATUS: childStatus }
+    })
+  } finally {
+    assert.equal(dirname(resolve(directory)), resolve(tmpdir()))
+    rmSync(directory, { recursive: true })
+  }
+}
+
+test('all image targets use the resource gate', () => {
+  const pipeline = readFileSync(join(root, 'Jenkinsfile'), 'utf8')
+  for (const target of ['test', 'production', 'certbot']) {
+    assert.ok(pipeline.includes(`sh deploy/build-image.sh --target ${target} `))
+  }
+  assert.doesNotMatch(pipeline, /docker build\s/)
+  assert.match(pipeline, /timeout\(time: 30, unit: 'MINUTES'\)/)
+})
+
+test('build forwards quoted arguments, enforces container budgets and propagates failure', { skip: !shellAvailable }, () => {
+  const result = runBuild('4194304', '23')
+  assert.equal(result.status, 23, result.stderr)
+  assert.match(result.stdout, /watchdog\r?\n--signal=TERM\r?\n--kill-after=30s\r?\n15m\r?\ndocker\r?\nbuild/)
+  assert.match(result.stdout, /builder=0\r?\nbuild/)
+  for (const argument of ['--memory=3g', '--memory-swap=3g', '--cpu-period=100000', '--cpu-quota=200000', '--force-rm']) {
+    assert.ok(result.stdout.split(/\r?\n/).includes(argument), argument)
+  }
+  assert.match(result.stdout, /--build-arg\r?\nVALUE=with space\r?\n-t\r?\nweb:test\r?\n\./)
+  assert.equal(runBuild('8388608').status, 0)
+  assert.equal(runBuild('8388608', '124').status, 124)
+})
+
+test('low or unreadable host memory refuses to start Docker', { skip: !shellAvailable }, () => {
+  for (const [memory, status] of [['4194303', 75], ['', 69], ['unknown', 69]]) {
+    const result = runBuild(memory)
+    assert.equal(result.status, status, result.stderr)
+    assert.equal(result.stdout, '')
+  }
+})