mcpField
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discovery-patterns

discovery-patterns

github.com/serac-labs云与 DevOps7759 次安装9 周前更新
代码仓库

关于 discovery-patterns

面向 ServiceNow 管理者和开发者的 Discovery 模式参考，涵盖网络与系统扫描、CMDB 填充及相关脚本示例。内容包括计划、凭据、探针、传感器、识别规则和运行状态。

主要功能

  1. 01介绍 Discovery 架构与相关表
  2. 02提供计划和 IP 范围示例
  3. 03涵盖凭据及其范围关联
  4. 04说明自定义探针与传感器
  5. 05展示 CI 识别和状态查询

适用场景

  1. 01配置网络扫描计划与范围
  2. 02管理 Discovery 凭据
  3. 03扩展数据采集和处理脚本
  4. 04检查运行状态及发现设备

MCP 相关

列出可用于查询 Discovery 表、查找工件、测试脚本和搜索已发现 CI 的 MCP 工具，并示范相关工作流。

安装

复制下面的命令，在终端中运行。

$npx skills add https://github.com/serac-labs/serac --skill discovery-patterns

安装后在 Claude Code 中输入/discovery-patterns确认已加载。

详细介绍

ServiceNow 的发现模式

发现功能通过扫描网络和系统，自动填充 CMDB。

发现架构

Discovery Schedule
    ↓
MID Server
    ↓
Probes (collect data)
    ↓
Sensors (process data)
    ↓
Identification Rules (match/create CIs)
    ↓
CMDB Population

关键表

表用途
discovery_schedule发现计划
discovery_credentials发现凭据
discovery_range要扫描的 IP 范围
cmdb_identification_ruleCI 标识
ecc_agentMID Server 记录
discovery_status发现运行状态

发现计划（ES5）

创建发现计划
// Create discovery schedule (ES5 ONLY!)
var schedule = new GlideRecord("discovery_schedule")
schedule.initialize()

// Basic info
schedule.setValue("name", "Data Center Discovery")
schedule.setValue("description", "Weekly discovery of data center infrastructure")

// Type
schedule.setValue("discover", "IP") // IP, CI, Cloud Resources

// Schedule
schedule.setValue("run_type", "weekly")
schedule.setValue("run_dayofweek", "sunday")
schedule.setValue("run_time", "02:00:00")

// MID Server
schedule.setValue("mid_server", getMIDServerSysId("DataCenterMID"))

// Enable
schedule.setValue("active", true)

var scheduleSysId = schedule.insert()

// Add IP range
addDiscoveryRange(scheduleSysId, "10.0.0.0", "10.0.255.255", "Data Center Network")
添加发现范围
// Add IP range to discovery schedule (ES5 ONLY!)
function addDiscoveryRange(scheduleSysId, startIP, endIP, name) {
  var range = new GlideRecord("discovery_range")
  range.initialize()
  range.setValue("schedule", scheduleSysId)
  range.setValue("name", name)
  range.setValue("type", "range")
  range.setValue("range_start", startIP)
  range.setValue("range_end", endIP)
  range.setValue("active", true)
  return range.insert()
}

// Add CIDR range
function addDiscoveryCIDR(scheduleSysId, cidr, name) {
  var range = new GlideRecord("discovery_range")
  range.initialize()
  range.setValue("schedule", scheduleSysId)
  range.setValue("name", name)
  range.setValue("type", "cidr")
  range.setValue("range", cidr) // e.g., '10.0.0.0/24'
  range.setValue("active", true)
  return range.insert()
}

发现凭据（ES5）

创建凭据
// Create Windows credential (ES5 ONLY!)
var cred = new GlideRecord("discovery_credentials")
cred.initialize()
cred.setValue("name", "Windows Domain Admin")
cred.setValue("type", "windows")
cred.setValue("user_name", "domain\\admin")
cred.setValue("password", "") // Set via secure method
cred.setValue("active", true)

// Credential order
cred.setValue("order", 100)

// Assign to credential affinity
cred.setValue("credential_alias", credentialAliasSysId)

cred.insert()
凭据关联性
// Create credential affinity (map credentials to IP ranges) (ES5 ONLY!)
var affinity = new GlideRecord("dscy_credentials_affinity")
affinity.initialize()
affinity.setValue("credential", credentialSysId)
affinity.setValue("range", discoveryRangeSysId)
affinity.setValue("order", 100)
affinity.insert()

自定义探针和传感器（ES5）

自定义探针
// Create custom probe script (ES5 ONLY!)
// Probes run on MID Server to collect data

// Table: discovery_probes_script
var probe = new GlideRecord("discovery_probes_script")
probe.initialize()
probe.setValue("name", "Custom Application Version")
probe.setValue("active", true)

// Probe script (runs on MID Server - ES5 ONLY!)
probe.setValue(
  "script",
  "var output = {};\n" +
    "\n" +
    "// Command to run\n" +
    'var cmd = "cat /opt/myapp/version.txt";\n' +
    "\n" +
    "try {\n" +
    "    var result = Packages.com.service_now.mid.probe.tpcon.OperatingSystemCommand.execute(cmd);\n" +
    "    output.app_version = result.getOutput().trim();\n" +
    "    output.success = true;\n" +
    "} catch (e) {\n" +
    "    output.success = false;\n" +
    "    output.error = e.message;\n" +
    "}\n" +
    "\n" +
    "output;",
)

probe.insert()
自定义传感器
// Create custom sensor (ES5 ONLY!)
// Sensors run on ServiceNow instance to process probe results

// Table: discovery_sensors_script
var sensor = new GlideRecord("discovery_sensors_script")
sensor.initialize()
sensor.setValue("name", "Process Custom Application Version")
sensor.setValue("active", true)
sensor.setValue("probe", probeSysId)

// Sensor script (runs on instance - ES5 ONLY!)
sensor.setValue(
  "script",
  "(function process(result, source) {\n" +
    "    var output = JSON.parse(result.output);\n" +
    "    \n" +
    "    if (!output.success) {\n" +
    '        gs.warn("Custom app discovery failed: " + output.error);\n' +
    "        return;\n" +
    "    }\n" +
    "    \n" +
    "    // Find or create CI\n" +
    "    var ci = source.getDeviceRecord();\n" +
    "    if (ci) {\n" +
    "        ci.u_custom_app_version = output.app_version;\n" +
    "        ci.update();\n" +
    '        gs.info("Updated CI with app version: " + output.app_version);\n' +
    "    }\n" +
    "})(result, source);",
)

sensor.insert()

标识规则（ES5）

CI 标识规则
// Create identification rule (ES5 ONLY!)
var rule = new GlideRecord("cmdb_identifier")
rule.initialize()

rule.setValue("name", "Server Identification")
rule.setValue("table", "cmdb_ci_server")
rule.setValue("active", true)

// Priority (lower = higher priority)
rule.setValue("order", 100)

// Identification entries (criteria)
rule.insert()

// Add identification criteria
var entry = new GlideRecord("cmdb_identifier_entry")
entry.initialize()
entry.setValue("identifier", rule.getUniqueValue())
entry.setValue("criterion_attributes", "serial_number") // Match by serial
entry.setValue("search_type", "equals")
entry.setValue("active", true)
entry.insert()
自定义标识脚本
// Identification script for complex matching (ES5 ONLY!)
// Table: cmdb_identifier_script

var script = new GlideRecord("cmdb_identifier_script")
script.initialize()
script.setValue("name", "Custom Server Match")
script.setValue("table", "cmdb_ci_server")
script.setValue("active", true)

script.setValue(
  "script",
  "(function identify(source) {\n" +
    '    var serial = source.getValue("serial_number");\n' +
    '    var hostname = source.getValue("name");\n' +
    "    \n" +
    "    // Try serial match first\n" +
    '    var gr = new GlideRecord("cmdb_ci_server");\n' +
    "    if (serial) {\n" +
    '        gr.addQuery("serial_number", serial);\n' +
    "        gr.query();\n" +
    "        if (gr.next()) {\n" +
    "            return gr.getUniqueValue();\n" +
    "        }\n" +
    "    }\n" +
    "    \n" +
    "    // Try hostname + IP match\n" +
    '    gr = new GlideRecord("cmdb_ci_server");\n' +
    '    gr.addQuery("name", hostname);\n' +
    '    gr.addQuery("ip_address", source.getValue("ip_address"));\n' +
    "    gr.query();\n" +
    "    if (gr.next()) {\n" +
    "        return gr.getUniqueValue();\n" +
    "    }\n" +
    "    \n" +
    "    // No match - return null to create new CI\n" +
    "    return null;\n" +
    "})(source);",
)

script.insert()

发现状态（ES5）

监控发现状态
// Check discovery run status (ES5 ONLY!)
function getDiscoveryStatus(scheduleSysId) {
  var status = new GlideRecord("discovery_status")
  status.addQuery("dscheduler", scheduleSysId)
  status.orderByDesc("sys_created_on")
  status.setLimit(1)
  status.query()

  if (status.next()) {
    return {
      state: status.state.getDisplayValue(),
      started: status.getValue("started"),
      completed: status.getValue("completed"),
      devices_found: status.getValue("devices_found"),
      devices_completed: status.getValue("devices_completed"),
      errors: status.getValue("error_count"),
    }
  }
  return null
}
发现设备结果
// Get discovered devices from a run (ES5 ONLY!)
function getDiscoveredDevices(statusSysId) {
  var devices = []

  var device = new GlideRecord("discovery_device_history")
  device.addQuery("status", statusSysId)
  device.query()

  while (device.next()) {
    devices.push({
      ip_address: device.getValue("source"),
      ci: device.cmdb_ci.getDisplayValue(),
      ci_class: device.getValue("ci_type"),
      state: device.state.getDisplayValue(),
      issues: device.getValue("issue_count"),
    })
  }

  return devices
}

MCP 工具集成

可用工具
工具用途
snow_query_table查询发现表
snow_artifact_manage查找制品（action='find'）
snow_execute_script测试发现脚本
snow_cmdb_search搜索已发现的 CI
示例工作流
// 1. Query active schedules
await snow_query_table({
  table: "discovery_schedule",
  query: "active=true",
  fields: "name,discover,run_type,mid_server",
})

// 2. Check recent discovery status
await snow_execute_script({
  script: `
        var status = getDiscoveryStatus('schedule_sys_id');
        gs.info(JSON.stringify(status));
    `,
})

// 3. Find discovery errors
await snow_query_table({
  table: "discovery_log",
  query: "level=error^sys_created_on>=javascript:gs.daysAgo(1)",
  fields: "message,source,sys_created_on",
})

最佳实践

  1. 凭据安全 - 使用凭据库
  2. 避开高峰时段安排 - 尽量降低对网络的影响
  3. 范围管理 - 按网络网段组织
  4. MID Server - 合理放置并配置容量
  5. 标识 - 明确匹配条件
  6. 协调 - 定期验证 CMDB
  7. 监控 - 跟踪发现运行状况
  8. 仅限 ES5 - 不使用现代 JavaScript 语法

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