Managing Rancher

Rancher Management Skill

Manage Rancher multi-cluster Kubernetes environments, projects, catalogs, and monitoring.

Core Helper Functions

#!/bin/bash

# Rancher API helper
rancher_api() {
    local method="${1:-GET}"
    local endpoint="$2"
    local data="${3:-}"
    local url="${RANCHER_URL:?RANCHER_URL required}"

    if [ -n "$data" ]; then
        curl -s -X "$method" \
            -H "Authorization: Bearer $RANCHER_TOKEN" \
            -H "Content-Type: application/json" \
            "${url}/v3/${endpoint}" \
            -d "$data"
    else
        curl -s -X "$method" \
            -H "Authorization: Bearer $RANCHER_TOKEN" \
            "${url}/v3/${endpoint}"
    fi
}

# Rancher kubectl context helper
rancher_kubectl() {
    local cluster_id="$1"
    shift
    curl -s -H "Authorization: Bearer $RANCHER_TOKEN" \
        "${RANCHER_URL}/k8s/clusters/${cluster_id}/api/v1/$*"
}

MANDATORY: Discovery-First Pattern

Always list clusters and projects before operating on specific resources.

Phase 1: Discovery

#!/bin/bash

echo "=== Rancher Server Info ==="
rancher_api GET "settings/server-version" | jq -r '.value'

echo ""
echo "=== Managed Clusters ==="
rancher_api GET "clusters" | jq -r '
    .data[] | "\(.id)\t\(.name)\t\(.state)\t\(.provider)\t\(.nodeCount // 0) nodes\t\(.version.gitVersion // "N/A")"
' | column -t | head -20

echo ""
echo "=== Cluster Health ==="
rancher_api GET "clusters" | jq -r '
    .data[] | "\(.name)\t\(.state)\t\(.componentStatuses // [] | map(.conditions[0].status) | join(","))"
' | column -t

echo ""
echo "=== Projects ==="
rancher_api GET "projects" | jq -r '
    .data[] | "\(.id)\t\(.name)\t\(.clusterId)\t\(.state)"
' | column -t | head -20

Output Rules

• TOKEN EFFICIENCY: Target <=50 lines per output
• Use Rancher API v3 with jq filtering
• Never dump full cluster specs -- extract key fields

Common Operations

Cluster Health Dashboard

#!/bin/bash
echo "=== Cluster Resource Summary ==="
rancher_api GET "clusters" | jq '
    .data[] | {
        name: .name,
        state: .state,
        nodes: .nodeCount,
        cpu: .allocatable.cpu,
        memory: .allocatable.memory,
        pods: .allocatable.pods,
        k8s_version: .version.gitVersion
    }' | head -40

echo ""
echo "=== Node Status per Cluster ==="
for cluster_id in $(rancher_api GET "clusters" | jq -r '.data[].id' | head -5); do
    CNAME=$(rancher_api GET "clusters/$cluster_id" | jq -r '.name')
    echo "--- $CNAME ---"
    rancher_api GET "clusters/${cluster_id}/nodes" | jq -r '
        .data[] | "\(.hostname)\t\(.state)\t\(.info.os.operatingSystem // "N/A")\t\(.allocatable.cpu) cpu\t\(.allocatable.memory) mem"
    ' | column -t | head -10
done

echo ""
echo "=== Cluster Events (warnings) ==="
rancher_api GET "clusters" | jq -r '.data[] | select(.state != "active") | "\(.name)\t\(.state)\t\(.transitioningMessage[0:60])"' | column -t

Project & Namespace Management

#!/bin/bash
CLUSTER_ID="${1:?Cluster ID required}"

echo "=== Projects in Cluster ==="
rancher_api GET "clusters/${CLUSTER_ID}/projects" | jq -r '
    .data[] | "\(.id)\t\(.name)\t\(.state)\t\(.description[0:40])"
' | column -t

echo ""
echo "=== Namespaces per Project ==="
for proj_id in $(rancher_api GET "clusters/${CLUSTER_ID}/projects" | jq -r '.data[].id' | head -10); do
    PNAME=$(rancher_api GET "projects/$proj_id" | jq -r '.name')
    echo "--- $PNAME ---"
    rancher_api GET "projects/${proj_id}/namespaces" | jq -r '
        .data[] | "\(.id)\t\(.name)\t\(.state)"
    ' | column -t | head -10
done

echo ""
echo "=== Resource Quotas ==="
rancher_api GET "clusters/${CLUSTER_ID}/projects" | jq '
    .data[] | select(.resourceQuota != null) | {
        project: .name,
        quota: .resourceQuota
    }' | head -20

Workload Monitoring

#!/bin/bash
PROJECT_ID="${1:?Project ID required}"

echo "=== Workloads ==="
rancher_api GET "projects/${PROJECT_ID}/workloads" | jq -r '
    .data[] | "\(.name)\t\(.type)\t\(.state)\t\(.scale // 1) replicas\t\(.containers[0].image)"
' | column -t | head -20

echo ""
echo "=== Unhealthy Workloads ==="
rancher_api GET "projects/${PROJECT_ID}/workloads" | jq -r '
    .data[] | select(.state != "active") | "\(.name)\t\(.state)\t\(.transitioningMessage[0:60])"
' | column -t

echo ""
echo "=== Services ==="
rancher_api GET "projects/${PROJECT_ID}/services" | jq -r '
    .data[] | "\(.name)\t\(.kind)\t\(.state)\t\(.clusterIp // "N/A")"
' | column -t | head -15

echo ""
echo "=== Ingresses ==="
rancher_api GET "projects/${PROJECT_ID}/ingresses" | jq -r '
    .data[] | "\(.name)\t\(.state)\t\(.rules[0].host // "N/A")"
' | column -t | head -10

Catalog & App Management

#!/bin/bash
echo "=== Global Catalogs ==="
rancher_api GET "catalogs" | jq -r '
    .data[] | "\(.name)\t\(.url)\t\(.state)\t\(.branch // "main")"
' | column -t

echo ""
echo "=== Installed Apps ==="
PROJECT_ID="${1:-}"
if [ -n "$PROJECT_ID" ]; then
    rancher_api GET "projects/${PROJECT_ID}/apps" | jq -r '
        .data[] | "\(.name)\t\(.state)\t\(.externalId)\t\(.version)"
    ' | column -t | head -15
fi

echo ""
echo "=== Available Charts ==="
rancher_api GET "templateVersions" | jq -r '
    .data[:20][] | "\(.externalId)\t\(.version)"
' | column -t | head -15

RBAC & User Management

#!/bin/bash
echo "=== Global Role Bindings ==="
rancher_api GET "globalRoleBindings" | jq -r '
    .data[] | "\(.userId // .groupPrincipalId)\t\(.globalRoleName)\t\(.name)"
' | column -t | head -20

echo ""
echo "=== Cluster Role Bindings ==="
CLUSTER_ID="${1:-}"
if [ -n "$CLUSTER_ID" ]; then
    rancher_api GET "clusterRoleTemplateBindings?clusterId=$CLUSTER_ID" | jq -r '
        .data[] | "\(.userId // .groupPrincipalId)\t\(.roleTemplateId)\t\(.clusterName)"
    ' | column -t | head -15
fi

echo ""
echo "=== Users ==="
rancher_api GET "users" | jq -r '
    .data[] | "\(.username)\t\(.name)\t\(.state)\t\(.enabled)"
' | column -t | head -15

Safety Rules

• Read-only by default: Use GET requests for cluster, project, workload inspection
• Never delete clusters or projects without explicit user confirmation
• Credential safety: Never expose Rancher API tokens or kubeconfig data
• Cluster operations: Scaling or upgrading clusters affects all workloads

Output Format

Present results as a structured report:

Managing Rancher 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

Common Pitfalls

• API version: Rancher v3 API differs significantly from v1 -- check the URL prefix
• Cluster ID format: Format is c-xxxxx -- use discovery to get correct IDs
• Project vs namespace: Projects are Rancher-specific groupings of namespaces -- not native K8s
• Catalog refresh: Catalogs can become stale -- refresh before checking available charts
• Fleet vs legacy: Rancher 2.6+ uses Fleet for GitOps -- check which deployment method is in use