proxy: add NodeGetInfo support

src/driver/controller-proxy/index.js

@@ -6,10 +6,11 @@ const fs = require('fs');
 const { Registry } = require("../../utils/registry");
 const { GrpcError, grpc } = require("../../utils/grpc");
 const path = require('path');
+const os = require("os");
 
 const volumeIdPrefix = 'v:';
 const snapshotIdPrefix = 's:';
-const NODE_TOPOLOGY_KEY_NAME = "org.democratic-csi.topology/node";
+const TOPOLOGY_DEFAULT_PREFIX = 'org.democratic-csi.topology';
 
 class CsiProxyDriver extends CsiBaseDriver {
   constructor(ctx, options) {
@@ -21,6 +22,7 @@ class CsiProxyDriver extends CsiBaseDriver {
     if (configFolder.slice(-1) == '/') {
       configFolder = configFolder.slice(0, -1);
     }
+    this.nodeIdSerializer = new NodeIdSerializer(ctx, options.proxy.nodeId || {});
 
     const timeoutMinutes = this.options.proxy.cacheTimeoutMinutes ?? 60;
     const defaultOptions = this.options;
@@ -142,7 +144,7 @@ class CsiProxyDriver extends CsiBaseDriver {
   }
 
   async checkAndRun(driver, methodName, call, defaultValue) {
-    if(typeof driver[methodName] !== 'function') {
+    if (typeof driver[methodName] !== 'function') {
       if (defaultValue) return defaultValue;
       // UNIMPLEMENTED could possibly confuse CSI CO into thinking
       // that driver does not support methodName at all.
@@ -225,7 +227,6 @@ class CsiProxyDriver extends CsiBaseDriver {
         );
     }
     const result = await this.checkAndRun(driver, 'CreateVolume', call);
-    this.ctx.logger.debug("CreateVolume result " + result);
     result.volume.volume_id = this.decorateVolumeHandle(connectionName, result.volume.volume_id);
     return result;
   }
@@ -292,9 +293,8 @@ class CsiProxyDriver extends CsiBaseDriver {
   }
 
   async NodeGetInfo(call) {
-    const nodeName = process.env.CSI_NODE_ID || os.hostname();
     const result = {
-      node_id: nodeName,
+      node_id: this.nodeIdSerializer.serialize(),
       max_volumes_per_node: 0,
     };
     const topologyType = this.options.proxy.nodeTopology?.type ?? 'cluster';
@@ -310,7 +310,7 @@ class CsiProxyDriver extends CsiBaseDriver {
       case 'node':
         result.accessible_topology = {
           segments: {
-            [prefix + '/node']: nodeName,
+            [prefix + '/node']: NodeIdSerializer.getLocalNodeName(),
           },
         };
         break
@@ -507,4 +507,124 @@ class DriverCache {
   }
 }
 
+const nodeIdCode_NodeName = 'n';
+const nodeIdCode_Hostname = 'h';
+const nodeIdCode_ISCSI = 'i';
+const nodeIdCode_NVMEOF = 'v';
+class NodeIdSerializer {
+  constructor(ctx, nodeIdConfig) {
+    this.ctx = ctx;
+    this.config = nodeIdConfig;
+  }
+
+  static getLocalNodeName() {
+    if (!process.env.CSI_NODE_ID) {
+      throw 'CSI_NODE_ID is required for proxy driver';
+    }
+    return process.env.CSI_NODE_ID;
+  }
+  static getLocalIqn() {
+    const iqnPath = '/etc/iscsi/initiatorname.iscsi';
+    const lines = fs.readFileSync(iqnPath, "utf8").split('\n');
+    for (let line of lines) {
+      line = line.replace(/#.*/, '').replace(/\s+$/, '');
+      if (line == '') {
+        continue;
+      }
+      const linePrefix = 'InitiatorName=';
+      if (line.startsWith(linePrefix)) {
+        const iqn = line.slice(linePrefix.length);
+        return iqn;
+      }
+    }
+    throw 'iqn is not found';
+  }
+  static getLocalNqn() {
+    const nqnPath = '/etc/nvme/hostnqn';
+    return fs.readFileSync(nqnPath, "utf8").replace(/\s+$/, '');
+  }
+
+  // returns { prefixName, suffix }
+  findPrefix(value, prefixMap) {
+    for (const prefixInfo of prefixMap) {
+      if (value.startsWith(prefixInfo.prefix)) {
+        return {
+          prefixName: prefixInfo.shortName,
+          suffix: value.split(prefixInfo.prefix.length),
+        };
+      }
+    }
+  }
+
+  serializeByPrefix(code, value, prefixMap) {
+    const prefixInfo = prefixMap.find(prefixInfo => value.startsWith(prefixInfo.prefix));
+    if (!prefixInfo) {
+      throw `node id: prefix is not found for value: ${value}`;
+    }
+    if (!prefixInfo.shortName.match(/^[0-9a-z]+$/)) {
+      throw `prefix short name must be alphanumeric, invalid name: '${prefixInfo.shortName}'`;
+    }
+    const suffix = value.substring(prefixInfo.prefix.length);
+    return code + prefixInfo.shortName + '=' + suffix;
+  }
+
+  deserializeFromPrefix(value, prefixMap, humanName) {
+    const prefixName = value.substring(0, value.indexOf('='));
+    const suffix = value.substring(value.indexOf('=') + 1);
+    const prefixInfo = prefixMap.find(prefixInfo => prefixInfo.shortName === prefixName);
+    if (!prefixInfo) {
+      throw new GrpcError(
+        grpc.status.INVALID_ARGUMENT,
+        `unknown node prefix short name for ${humanName}: ${value}`
+      );
+    }
+    return prefixInfo.prefix + suffix;
+  }
+
+  // returns a single string that incorporates node id components specified in config.parts
+  serialize() {
+    let result = '';
+    if (this.config.parts?.nodeName ?? true) {
+      result += '/' + nodeIdCode_NodeName + '=' + NodeIdSerializer.getLocalNodeName();
+    }
+    if (this.config.parts?.hostname ?? false) {
+      result += '/' + nodeIdCode_Hostname + '=' + os.hostname();
+    }
+    if (this.config.parts?.iqn ?? false) {
+      result += '/' + this.serializeByPrefix(nodeIdCode_ISCSI, NodeIdSerializer.getLocalIqn(), this.config.iqnPrefix);
+    }
+    if (this.config.parts?.nqn ?? false) {
+      result += '/' + this.serializeByPrefix(nodeIdCode_NVMEOF, NodeIdSerializer.getLocalNqn(), this.config.nqnPrefix);
+    }
+    if (result === '') {
+      throw 'node id can not be empty';
+    }
+    // remove starting /
+    return result.slice(1);
+  }
+
+  // takes a string generated by NodeIdSerializer.serialize
+  // returns an { nodeName, iqn, nqn } if they exist in nodeId
+  deserialize(nodeId) {
+    const result = {};
+    for (const v in nodeId.split("/")) {
+      switch (v[0]) {
+        case nodeIdCode_NodeName:
+          result.nodeName = v.substring(v.indexOf('=') + 1);
+          continue;
+        case nodeIdCode_Hostname:
+          result.hostname = v.substring(v.indexOf('=') + 1);
+          continue;
+        case nodeIdCode_ISCSI:
+          result.iqn = this.deserializeFromPrefix(v, this.config.iqnPrefix, 'iSCSI');
+          continue;
+        case nodeIdCode_NVMEOF:
+          result.nqn = this.deserializeFromPrefix(v, this.config.nqnPrefix, 'NVMEoF');
+          continue;
+      }
+    }
+    return result;
+  }
+}
+
 module.exports.CsiProxyDriver = CsiProxyDriver;

src/driver/controller-proxy/nodeInfo.md

@@ -8,12 +8,11 @@ There are 2 important values:
 - topology
 - node ID
 
-There are only 2 types of topology in democratic-csi:
-topology without constraints and node-local volumes.
-It's easy to account for with proxy settings.
+# Node ID
 
-Node ID is a bit harder to solve, but this page suggests a solution.
-Also, currently no real driver actually needs `node_id` to work,
+Node ID is a bit tricky to solve, because of limited field length.
+
+Currently no real driver actually needs `node_id` to work,
 so all of this is mostly a proof-of-concept.
 A proof that you can create a functional proxy driver even with current CSI spec.
 
@@ -23,7 +22,7 @@ before calling the actual real driver method.
 Node ID docs are not a part of user documentation because currently this is very theoretical.
 Current implementation works fine but doesn't do anything useful for users.
 
-# Node info: config example
+## Node ID: config example
 
 ```yaml
 # configured in root proxy config
@@ -62,7 +61,7 @@ proxy:
     nodeIdType: nodeName
 ```
 
-# Reasoning why such complex node_id is required
+## Node ID: Reasoning why such complex node_id is required
 
 `node_name + iqn + nqn` can be very long.
 
@@ -89,7 +88,7 @@ For example, if driver needs iqn, proxy will find field in node id starting with
 search `proxy.nodeId.iqnPrefix` for entry with `shortName = 1`, and then set `node_id` to
 `proxy.nodeId.iqnPrefix[name=1].prefix` + `qwerty`
 
-## Alternatives to prefixes
+## Node ID: Alternatives to prefixes
 
 Each driver can override `node_id` based on node name.
 
@@ -118,3 +117,28 @@ Still, if this were to be useful for some reason, this is fully compatible with
 
 Theoretically, more info can be extracted from node to be used in `nodeIdTemplate`,
 provided the info is short enough to fit into `node_id` length limit.
+
+# Topology
+
+There are 3 cases of cluster topology:
+
+- Each node has unique topology domain (`local` drivers)
+- All nodes are the same (usually the case for non-local drivers)
+- Several availability zones that can contain several nodes
+
+Simple cases are currently supported by the proxy.
+Custom availability zones are TBD.
+
+Example configuration:
+
+```yaml
+proxy:
+  nodeTopology:
+    # allowed values:
+    # node - each node has its own storage
+    # cluster - the whole cluster has unified storage
+    type: node
+    # topology reported by CSI driver is reflected in k8s as node labels.
+    # you may want to set unique prefixes on different drivers to avoid collisions
+    prefix: org.democratic-csi.topology
+```