feat(runner): provide Docker before workflow steps

.gitea/workflows/pod-smoke.yml

@@ -20,28 +20,11 @@ jobs:
             >/dev/null
           test "$(id -u)" = 2000
 
-      - name: Start job-local Docker
-        shell: bash
-        run: |
-          set -euo pipefail
-          findmnt /var/lib/docker
-          sudo nohup dockerd \
-            --host=unix:///var/run/docker.sock \
-            --storage-driver=overlay2 \
-            >/tmp/dockerd.log 2>&1 &
-          for _ in {1..60}; do
-            if docker info >/dev/null 2>&1; then
-              exit 0
-            fi
-            sleep 1
-          done
-          cat /tmp/dockerd.log
-          exit 1
-
       - name: Build and run image
         shell: bash
         run: |
           set -euo pipefail
+          findmnt /var/lib/docker
           context=$(mktemp -d)
           cleanup() {
             docker image rm --force pod-docker-smoke:test \

.gitea/workflows/publish-images.yml

@@ -63,6 +63,10 @@ jobs:
           set -euo pipefail
           set +x
 
+          # Bootstrap the image that first introduces automatic Docker setup.
+          # Once deployed, the job-started hook makes this an idempotent no-op.
+          sudo scripts/setup-job-docker
+
           : "${GITHUB_SHA:?GITHUB_SHA is required}"
           image_tag="sha-${GITHUB_SHA}"
           docker_config=$(mktemp -d)

.gitea/workflows/vm-kind-smoke.yml

@@ -7,64 +7,21 @@ on:
 
 jobs:
   kind:
-    runs-on: [self-hosted, vm-dev]
+    runs-on: [self-hosted, vm]
     steps:
-      - name: Start job-local Docker
+      - name: Prepare nested kubelet device
         shell: bash
         run: |
           set -euo pipefail
           if [[ ! -e /dev/kmsg ]]; then
             sudo mknod /dev/kmsg c 1 11
           fi
-          sudo install -d /var/lib/docker
-          sudo truncate -s 20G /tmp/docker-data.img
-          sudo mkfs.ext4 -F /tmp/docker-data.img
-          if [[ ! -e /dev/loop-control ]]; then
-            sudo mknod /dev/loop-control c 10 237
-          fi
-          for minor in {0..7}; do
-            if [[ ! -e "/dev/loop${minor}" ]]; then
-              sudo mknod "/dev/loop${minor}" b 7 "$minor"
-            fi
-          done
-          loop_device=$(sudo losetup --find --show /tmp/docker-data.img)
-          sudo mount "$loop_device" /var/lib/docker
-          findmnt /var/lib/docker
-
-          # A nested systemd needs a domain cgroup namespace. This is the
-          # cgroup v2 nesting initialization performed by the official DinD
-          # entrypoint, kept here because the shared runner image deliberately
-          # does not carry a second DinD-specific entrypoint.
-          if [[ -f /sys/fs/cgroup/cgroup.controllers ]]; then
-            sudo sh -c '
-              mkdir -p /sys/fs/cgroup/init
-              while read -r pid; do
-                printf "%s\n" "$pid" \
-                  >/sys/fs/cgroup/init/cgroup.procs 2>/dev/null || true
-              done </sys/fs/cgroup/cgroup.procs
-              sed -e "s/ / +/g" -e "s/^/+/" \
-                /sys/fs/cgroup/cgroup.controllers \
-                >/sys/fs/cgroup/cgroup.subtree_control
-            '
-          fi
-
-          sudo nohup dockerd \
-            --host=unix:///var/run/docker.sock \
-            --storage-driver=overlay2 \
-            >/tmp/dockerd.log 2>&1 &
-          for _ in {1..60}; do
-            if docker info >/dev/null 2>&1; then
-              exit 0
-            fi
-            sleep 1
-          done
-          cat /tmp/dockerd.log
-          exit 1
 
       - name: Verify Docker
         shell: bash
         run: |
           set -euo pipefail
+          findmnt /var/lib/docker
           docker info
           echo '### runner cgroup'
           cat /proc/self/cgroup

.gitea/workflows/vm-runtime-smoke.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   runtime:
-    runs-on: [self-hosted, vm-dev]
+    runs-on: [self-hosted, vm]
     steps:
       - name: Verify workload identity socket
         shell: bash

README.md

@@ -36,8 +36,9 @@ runs-on: [self-hosted, vm]
   entry；不持有 OpenSandbox API key、Gitea token 或 Bao 凭据。身份与 Pool 契约见
   [`docs/opensandbox-runner.md`](docs/opensandbox-runner.md)。
 - Pod executor：在 Kubernetes 中创建一次性 privileged Pod；Pod 内的 workflow 使用
-  host executor，Docker、BuildKit 和 kind 等工具由 pipeline 按需 setup。Runner 固定在
-  支持原生 job hooks 的 3.x 版本，在 workflow 第一步前等待实际任务对应的 SVID。
+  host executor。Runner 固定在支持原生 job hooks 的 3.x 版本，在 workflow 第一步前
+  等待实际任务对应的 SVID，并启动 job-local Docker daemon；workflow 可直接使用与
+  GitHub-hosted runner 相同的 Docker/BuildKit action。
 - `jwt-broker`：早期共享 Kubernetes runner 的过渡实验；目标架构不部署它，每个
   动态 Pod 或 VM 直接取得自己的 SPIFFE 身份。
 

container/runner.Dockerfile

@@ -29,6 +29,7 @@ COPY --from=spire /opt/spire/bin/spire-agent /opt/spire/bin/spire-agent
 COPY config/runner.yaml /etc/gitea-runner/config.yaml
 COPY --chmod=0755 scripts/gitea-job-started /usr/local/libexec/gitea-job-started
 COPY --chmod=0755 scripts/gitea-opensandbox-runner /usr/local/libexec/gitea-opensandbox-runner
+COPY --chmod=0755 scripts/setup-job-docker /usr/local/libexec/setup-job-docker
 
 VOLUME ["/data"]
 ENV HOME=/home/runner

docs/opensandbox-runner.md

@@ -42,8 +42,8 @@ UID attestation 的临时 Agent 失去父级。
 
 - runner 镜像包含 Gitea Runner、Node.js action userspace、SPIRE CLI、Docker 工具和
   identity gate；Pod 与 VM backend 使用同一个镜像；
-- runner UID 2000；SPIRE Agent 独立运行，需要 Docker 的 workflow 通过 sudo 在
-  privileged executor 内启动 job-local daemon；
+- runner UID 2000；SPIRE Agent 独立运行；job-started hook 在第一步 workflow 之前
+  启动 job-local Docker daemon，业务 workflow 不负责 runner 基础设施初始化；
 - Kata VM 中 Docker 数据使用 guest 内的 loop-backed ext4，并随 sandbox 一起删除；
 - `self-hosted` 必须是所有 runner labels 的前缀；
 - ephemeral/once runner 完成一项任务后退出。

scripts/gitea-job-started

@@ -10,6 +10,7 @@ while [ "$(date +%s)" -lt "$deadline" ]; do
         -audience ci-job-ready \
         -socketPath "$socket" \
         >/dev/null 2>&1; then
+        /usr/local/libexec/setup-job-docker
         exit 0
     fi
     sleep 1

scripts/setup-job-docker

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if docker info >/dev/null 2>&1; then
+  printf '%s\n' 'job Docker daemon is already ready'
+  exit 0
+fi
+
+storage_size=${DOCKER_DATA_SIZE:-20G}
+storage_driver=${DOCKER_STORAGE_DRIVER:-overlay2}
+wait_seconds=${DOCKER_START_WAIT_SECONDS:-60}
+
+sudo install -d /var/lib/docker
+if ! mountpoint --quiet /var/lib/docker; then
+  printf '%s\n' "preparing ${storage_size} loop-backed Docker storage"
+  if [[ ! -e /dev/loop-control ]]; then
+    sudo mknod /dev/loop-control c 10 237
+  fi
+  for minor in {0..7}; do
+    if [[ ! -e "/dev/loop${minor}" ]]; then
+      sudo mknod "/dev/loop${minor}" b 7 "$minor"
+    fi
+  done
+  sudo truncate -s "$storage_size" /tmp/docker-data.img
+  sudo mkfs.ext4 -F /tmp/docker-data.img
+  loop_device=$(sudo losetup --find --show /tmp/docker-data.img)
+  sudo mount "$loop_device" /var/lib/docker
+else
+  printf '%s\n' 'using mounted Docker storage at /var/lib/docker'
+fi
+
+if [[ -f /sys/fs/cgroup/cgroup.controllers ]]; then
+  sudo sh -c '
+    mkdir -p /sys/fs/cgroup/init
+    while read -r pid; do
+      printf "%s\n" "$pid" \
+        >/sys/fs/cgroup/init/cgroup.procs 2>/dev/null || true
+    done </sys/fs/cgroup/cgroup.procs
+    sed -e "s/ / +/g" -e "s/^/+" \
+      /sys/fs/cgroup/cgroup.controllers \
+      >/sys/fs/cgroup/cgroup.subtree_control
+  '
+fi
+
+sudo nohup dockerd \
+  --host=unix:///var/run/docker.sock \
+  --storage-driver="$storage_driver" \
+  >/tmp/dockerd.log 2>&1 &
+printf '%s\n' 'waiting for job Docker daemon'
+for ((attempt = 0; attempt < wait_seconds; attempt++)); do
+  if docker info >/dev/null 2>&1; then
+    findmnt /var/lib/docker
+    docker info --format \
+      '{{json .ServerVersion}} {{json .Driver}} {{json .CgroupVersion}}'
+    exit 0
+  fi
+  sleep 1
+done
+
+cat /tmp/dockerd.log
+exit 1