一、无法连接到docker官方源

报错如下：

root@————————————————:~# apt update
Hit:1 http://mirrors.cloud.aliyuncs.com/ubuntu jammy InRelease
Hit:2 http://mirrors.cloud.aliyuncs.com/ubuntu jammy-updates InRelease
Hit:3 http://mirrors.cloud.aliyuncs.com/ubuntu jammy-backports InRelease
Hit:4 http://mirrors.cloud.aliyuncs.com/ubuntu jammy-security InRelease
Ign:5 https://download.docker.com/linux/ubuntu jammy InRelease
Ign:5 https://download.docker.com/linux/ubuntu jammy InRelease
Ign:5 https://download.docker.com/linux/ubuntu jammy InRelease
Err:5 https://download.docker.com/linux/ubuntu jammy InRelease
  Could not handshake: Error in the pull function. [IP: 3.170.229.111 443]
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
3 packages can be upgraded. Run 'apt list --upgradable' to see them.
W: Failed to fetch https://download.docker.com/linux/ubuntu/dists/jammy/InRelease  Could not handshake: Error in the pull function. [IP: 3.170.229.111 443]
W: Some index files failed to download. They have been ignored, or old ones used instead.
root@iZuf6dcmbpbqrs8t33kcyhZ:~# sudo apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Package docker-ce is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'docker-ce' has no installation candidate
E: Unable to locate package docker-ce-cli
E: Unable to locate package containerd.io
E: Couldn't find any package by glob 'containerd.io'
E: Unable to locate package docker-buildx-plugin
E: Unable to locate package docker-compose-plugin

问题是由于 访问 Docker 官方源失败 导致的安装包无法获取。报错关键是这一句：

Could not handshake: Error in the pull function. [IP: 3.170.229.111 443]

这说明你的服务器当前网络环境（很可能是在国内）无法成功与 download.docker.com 建立 TLS 握手，属于网络连接问题（通常是被墙）。

 解决方案：使用 Docker 国内镜像源（中科大 / 阿里云等）

我们将切换到 国内加速源 来完成 Docker 安装。

 步骤一：清理错误的 Docker 源

执行以下命令删除失效源：

sudo rm /etc/apt/sources.list.d/docker.list
sudo apt update

 步骤二：添加国内源（中科大源）

创建密钥：

curl -fsSL https://mirrors.ustc.edu.cn/docker-ce/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg

写入源配置（适配 jammy）：

echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://mirrors.ustc.edu.cn/docker-ce/linux/ubuntu \
  $(lsb_release -cs) stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

 步骤三：更新并安装 Docker

sudo apt update
sudo apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

 可选步骤：配置镜像加速器（用于 Docker 拉取镜像加速）

创建或编辑文件 /etc/docker/daemon.json：

sudo mkdir -p /etc/docker

sudo tee /etc/docker/daemon.json > /dev/null <<EOF
{
  "registry-mirrors": ["https://registry.docker-cn.com"]
}
EOF

重启 Docker：

sudo systemctl daemon-reexec
sudo systemctl restart docker

完成以上步骤后，应该可以顺利安装并运行 Docker 以及 Docker Compose。