Checkmk Monitoring Skill

Query, analyze, and manage Checkmk monitoring data using the Checkmk REST API.

API Overview

Checkmk uses a REST API at https://<CMK_HOST>/<SITE>/check_mk/api/1.0.

Core Helper Function

#!/bin/bash

cmk_api() {
    local method="$1"
    local endpoint="$2"
    local data="${3:-}"
    local url="${CHECKMK_URL}/check_mk/api/1.0/${endpoint}"
    if [ -n "$data" ]; then
        curl -s -X "$method" "$url" \
            -H "Authorization: Bearer ${CHECKMK_USER} ${CHECKMK_SECRET}" \
            -H "Content-Type: application/json" \
            -H "Accept: application/json" \
            -d "$data"
    else
        curl -s -X "$method" "$url" \
            -H "Authorization: Bearer ${CHECKMK_USER} ${CHECKMK_SECRET}" \
            -H "Accept: application/json"
    fi
}

MANDATORY: Discovery-First Pattern

Always discover hosts, folders, and host groups before querying.

Phase 1: Discovery

#!/bin/bash

echo "=== Site Version ==="
cmk_api GET "version" | jq -r '"Version: \(.versions.checkmk)\nEdition: \(.edition)"'

echo ""
echo "=== Folders ==="
cmk_api GET "domain-types/folder_config/collections/all" \
    | jq -r '.value[] | "\(.id)\t\(.title)"' | head -15

echo ""
echo "=== Hosts ==="
cmk_api GET "domain-types/host_config/collections/all" \
    | jq -r '.value[] | "\(.id)\t\(.title)\t\(.extensions.folder // "/")"' | head -25

echo ""
echo "=== Host Groups ==="
cmk_api GET "domain-types/host_group_config/collections/all" \
    | jq -r '.value[] | "\(.id)\t\(.title)"' | head -15

echo ""
echo "=== Contact Groups ==="
cmk_api GET "domain-types/contact_group_config/collections/all" \
    | jq -r '.value[] | "\(.id)\t\(.title)"' | head -10

Phase 2: Analysis

#!/bin/bash

echo "=== Host Problems ==="
cmk_api GET "domain-types/host/collections/all?query=%7B%22op%22%3A%22!%3D%22%2C%22left%22%3A%22state%22%2C%22right%22%3A%220%22%7D" \
    | jq -r '.value[] | "\(.extensions.state | if . == 1 then "DOWN" elif . == 2 then "UNREACH" else "UNKNOWN" end)\t\(.title)\t\(.extensions.last_check // "N/A")"' | head -15

echo ""
echo "=== Service Problems ==="
cmk_api GET "domain-types/service/collections/all?query=%7B%22op%22%3A%22!%3D%22%2C%22left%22%3A%22state%22%2C%22right%22%3A%220%22%7D" \
    | jq -r '.value[] | "\(.extensions.state | if . == 1 then "WARN" elif . == 2 then "CRIT" else "UNKNOWN" end)\t\(.extensions.host_name)/\(.title)\t\(.extensions.plugin_output[0:50])"' | head -20

echo ""
echo "=== Status Summary ==="
cmk_api GET "domain-types/host/collections/all" | jq -r '[.value[].extensions.state] | group_by(.) | map({state: (.[0] | if . == 0 then "UP" elif . == 1 then "DOWN" else "UNREACH" end), count: length})[] | "\(.state): \(.count)"'

echo ""
echo "=== Scheduled Downtimes ==="
cmk_api GET "domain-types/downtime/collections/all" \
    | jq -r '.value[] | "\(.extensions.host_name)\t\(.extensions.service_description // "HOST")\t\(.extensions.author)\t\(.extensions.comment[0:40])"' | head -10

Output Rules

• TOKEN EFFICIENCY: Target ≤50 lines — use query filters and head in output
• Host states: 0=UP, 1=DOWN, 2=UNREACHABLE
• Service states: 0=OK, 1=WARNING, 2=CRITICAL, 3=UNKNOWN
• Use Livestatus query expressions in query parameter for server-side filtering

Output Format

Present results as a structured report:

Managing Checkmk 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

Shortcut	Counter	Why
"I'll skip discovery and check known resources"	Always run Phase 1 discovery first	Resource names change, new resources appear — assumed names cause errors
"The user only asked for a quick check"	Follow the full discovery → analysis flow	Quick checks miss critical issues; structured analysis catches silent failures
"Default configuration is probably fine"	Audit configuration explicitly	Defaults often leave logging, security, and optimization features disabled
"Metrics aren't needed for this"	Always check relevant metrics when available	API/CLI responses show current state; metrics reveal trends and intermittent issues
"I don't have access to that"	Try the command and report the actual error	Assumed permission failures prevent useful investigation; actual errors are informative