https://hangyan.github.io/categories/cni/Recent content in CNI on 涯余的博客Hugozhhang.yan@hotmail.com (涯余)hang.yan@hotmail.com (涯余)Fri, 17 Sep 2021 14:05:47 +0800https://hangyan.github.io/post/2021-cni-ipam/Fri, 17 Sep 2021 14:05:47 +0800hang.yan@hotmail.com (涯余)https://hangyan.github.io/post/2021-cni-ipam/<p>CNI相关笔记，本文主要记录下 IPAM 功能相关。</p> <p>CNI的职责包括给 Container 分配网络设备，并且分配IP. IPAM(IP Address Management)就是指IP分配相关的功能和规范。</p> <p>CNI本身只是一个规范，不同的实现在 IPAM 方面的功能集也不尽相同。下面将首先尝试说明下不同 CNI在这块的实现。</p> <h2 id="cni实现">CNI实现</h2> <h3 id="calico">Calico</h3> <p>calico开发的IPAM组件叫 <code>calico-ipam</code>, 它使用 calico 的 IP pool resource来管理 IP. 它的主要优势就是可以将 pool 分割成小的 block, 并且可以动态对分配给不同的 node. node 上的 ip 利用率会更高，并且可扩展性也很好。calico 目前也支持给不同的 namespace分配不同的 ip pool. 从大的方面来看，其实最终 各个CNI 实现要解决的问题都是类似的，一般区别只是 dataplane 以及具体的 CRD的设计不太一样。所以这些功能很可能(已经有了或者以后会有)出现在其他的 CNI 上面。</p> <p>下面看一个实际的例子:</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-yaml" data-lang="yaml"><span class="line"><span class="cl"><span class="nt">apiVersion</span><span class="p">:</span><span class="w"> </span><span class="l">projectcalico.org/v3</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="nt">kind</span><span class="p">:</span><span class="w"> </span><span class="l">IPPool</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="nt">metadata</span><span class="p">:</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">name</span><span class="p">:</span><span class="w"> </span><span class="l">external-pool</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="nt">spec</span><span class="p">:</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">cidr</span><span class="p">:</span><span class="w"> </span><span class="m">172.16.0.0</span><span class="l">/26</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">blockSize</span><span class="p">:</span><span class="w"> </span><span class="m">29</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">ipipMode</span><span class="p">:</span><span class="w"> </span><span class="l">Always</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">natOutgoing</span><span class="p">:</span><span class="w"> </span><span class="kc">true</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="nn">---</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="nt">apiVersion</span><span class="p">:</span><span class="w"> </span><span class="l">projectcalico.org/v3</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="nt">kind</span><span class="p">:</span><span class="w"> </span><span class="l">IPPool</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="nt">metadata</span><span class="p">:</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">name</span><span class="p">:</span><span class="w"> </span><span class="l">internal-pool</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="nt">spec</span><span class="p">:</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">cidr</span><span class="p">:</span><span class="w"> </span><span class="m">192.169.0.0</span><span class="l">/24</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">blockSize</span><span class="p">:</span><span class="w"> </span><span class="m">29</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">ipipMode</span><span class="p">:</span><span class="w"> </span><span class="l">Always</span><span class="w"> </span></span></span><span class="line"><span class="cl"><span class="w"> </span><span class="nt">natOutgoing</span><span class="p">:</span><span class="w"> </span><span class="kc">true</span><span class="w"> </span></span></span></code></pre></div><p>这里面可以创建两个 IPPool, 并且可以通过给 NS 打 label 的方式，分配给不同的 NS.</p>