---

name: discovery-patterns description: This skill should be used when the user asks to "discovery", "discover", "probe", "sensor", "identification", "discovery schedule", "MID server", "network scan", or any ServiceNow Discovery development. license: Apache-2.0 compatibility: Designed for Snow-Code and ServiceNow development metadata: author: groeimetai version: "1.0.0" category: servicenow tools:

• snow_discovery_schedule_create
• snow_cmdb_search
• snow_query_table
• snow_execute_script_with_output

---

Discovery Patterns for ServiceNow

Discovery automatically populates the CMDB by scanning networks and systems.

Discovery Architecture

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

Key Tables

Discovery Schedules (ES5)

Create Discovery Schedule

Copy// 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');

Add Discovery Range

Copy// 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();
}

Discovery Credentials (ES5)

Create Credentials

Copy// 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();

Credential Affinity

Copy// 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();

Custom Probes and Sensors (ES5)

Custom Probe

Copy// 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();

Custom Sensor

Copy// 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();

Identification Rules (ES5)

CI Identification Rule

Copy// 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();

Custom Identification Script

Copy// 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();

Discovery Status (ES5)

Monitor Discovery Status

Copy// 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;
}

Discovery Device Results

Copy// 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 Tool Integration

Available Tools

Example Workflow

Copy// 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_with_output({
    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'
});

Best Practices

1. Credential Security - Use credential vault
2. Schedule Off-Peak - Minimize network impact
3. Range Management - Organize by network segment
4. MID Server - Proper placement and sizing
5. Identification - Clear matching criteria
6. Reconciliation - Regular CMDB validation
7. Monitoring - Track discovery health
8. ES5 Only - No modern JavaScript syntax