Managing Nagios

Nagios Monitoring Skill

Query, analyze, and manage Nagios monitoring data using the Nagios API (Core or XI).

API Overview

Nagios XI uses a REST API at https://<NAGIOS_HOST>/nagiosxi/api/v1. Nagios Core uses the CGI interface or Livestatus.

Core Helper Function

#!/bin/bash

nagios_api() {
    local endpoint="$1"
    local params="${2:-}"
    curl -s "${NAGIOS_URL}/nagiosxi/api/v1/${endpoint}?apikey=${NAGIOS_API_KEY}&${params}"
}

# For Nagios Core with Livestatus
nagios_ls() {
    local query="$1"
    echo "$query" | unixcat "${NAGIOS_LIVESTATUS_SOCKET:-/var/nagios/rw/live}"
}

MANDATORY: Discovery-First Pattern

Always discover hostgroups, hosts, and servicegroups before querying.

Phase 1: Discovery

#!/bin/bash

echo "=== Host Groups ==="
nagios_api "objects/hostgrouplist" | jq -r '.hostgrouplist[] | "\(.hostgroup_name)\thosts:\(.members | length)"' | head -15

echo ""
echo "=== Hosts ==="
nagios_api "objects/hoststatus" "records=25" | jq -r '.hoststatus[] | "\(.host_name)\t\(.status_text)\t\(.address)\t\(.last_check[0:16])"' | head -25

echo ""
echo "=== Service Groups ==="
nagios_api "objects/servicegrouplist" | jq -r '.servicegrouplist[] | "\(.servicegroup_name)"' | head -15

echo ""
echo "=== Contact Groups ==="
nagios_api "objects/contactgrouplist" | jq -r '.contactgrouplist[] | "\(.contactgroup_name)"' | head -10

Phase 2: Analysis

#!/bin/bash

echo "=== Host Problems ==="
nagios_api "objects/hoststatus" "hoststatus_types=12" \
    | jq -r '.hoststatus[] | "\(.status_text)\t\(.host_name)\t\(.status_information[0:60])"' | head -15

echo ""
echo "=== Service Problems ==="
nagios_api "objects/servicestatus" "servicestatus_types=28" \
    | jq -r '.servicestatus[] | "\(.status_text)\t\(.host_name)/\(.service_description)\t\(.status_information[0:50])"' | head -20

echo ""
echo "=== Status Summary ==="
nagios_api "objects/hoststatus" | jq -r '[.hoststatus[] | .status_text] | group_by(.) | map({status: .[0], count: length})[] | "\(.status): \(.count)"'
nagios_api "objects/servicestatus" | jq -r '[.servicestatus[] | .status_text] | group_by(.) | map({status: .[0], count: length})[] | "\(.status): \(.count)"'

echo ""
echo "=== Scheduled Downtimes ==="
nagios_api "objects/downtimedata" | jq -r '.downtimedata[] | "\(.host_name)\t\(.service_description // "HOST")\t\(.start_time[0:16])-\(.end_time[0:16])\t\(.author)"' | head -10

echo ""
echo "=== Recent Notifications ==="
nagios_api "objects/notificationlist" "records=15" \
    | jq -r '.notificationlist[] | "\(.start_time[0:16])\t\(.host_name)\t\(.service_description // "HOST")\t\(.notification_type)"' | head -15

Output Rules

• TOKEN EFFICIENCY: Target ≤50 lines — use records parameter and filter by status types
• Status types bitmask: 1=OK/UP, 2=WARNING/DOWN, 4=CRITICAL/UNREACHABLE, 8=UNKNOWN, 16=PENDING
• Use hoststatus_types and servicestatus_types to filter at API level

Output Format

Present results as a structured report:

Managing Nagios Report
══════════════════════
Resources discovered: [count]

Resource       Status    Key Metric    Issues
──────────────────────────────────────────────
[name]         [ok/warn] [value]       [findings]

Summary: [total] resources | [ok] healthy | [warn] warnings | [crit] critical
Action Items: [list of prioritized findings]

Target ≤50 lines of output. Use tables for multi-resource comparisons.

Anti-Hallucination Rules

1. NEVER assume resource names — always discover via CLI/API in Phase 1 before referencing in Phase 2.
2. NEVER fabricate metric names or dimensions — verify against the service documentation or --help output.
3. NEVER mix CLI commands between service versions — confirm which version/API you are targeting.
4. ALWAYS use the discovery → verify → analyze chain — every resource referenced must have been discovered first.
5. ALWAYS handle empty results gracefully — an empty response is valid data, not an error to retry.

Counter-Rationalizations