High Availability & Disaster Recovery

#!/bin/bash
# CDE Regional Failover Script (2026 - includes agent workloads)

set -euo pipefail

PRIMARY_REGION="us-east-1"
DR_REGION="eu-west-1"
HEALTH_ENDPOINT="https://cde.company.com/api/v2/health"
AGENT_HEALTH_ENDPOINT="https://cde.company.com/api/v2/agents/health"
SLACK_WEBHOOK="https://hooks.slack.com/services/xxx"

# Check primary health (workspaces + agents)
check_health() {
    local ws_status=$(curl -s -o /dev/null -w "%{http_code}" $HEALTH_ENDPOINT --max-time 10)
    local agent_status=$(curl -s -o /dev/null -w "%{http_code}" $AGENT_HEALTH_ENDPOINT --max-time 10)
    [[ "$ws_status" == "200" ]] && [[ "$agent_status" == "200" ]]
}

# Notify team
notify() {
    curl -X POST $SLACK_WEBHOOK \
        -H 'Content-Type: application/json' \
        -d "{\"text\": \"$1\"}"
}

# Failover database
failover_db() {
    echo "Promoting DR database to primary..."
    aws rds promote-read-replica \
        --db-instance-identifier cde-db-dr \
        --region $DR_REGION
}

# Drain and redirect agent task queues
failover_agents() {
    echo "Pausing agent task dispatch in $PRIMARY_REGION..."
    aws sqs set-queue-attributes \
        --queue-url $PRIMARY_QUEUE_URL \
        --attributes '{"ReceiveMessageWaitTimeSeconds":"0"}'

    echo "Activating DR agent queue consumers in $DR_REGION..."
    kubectl --context $DR_CONTEXT scale deployment agent-consumer \
        --replicas=10

    echo "Checkpointing in-flight agent tasks..."
    curl -X POST "https://cde.company.com/api/v2/agents/checkpoint-all" \
        --max-time 30
}

# Update DNS
update_dns() {
    echo "Updating DNS to DR region..."
    aws route53 change-resource-record-sets \
        --hosted-zone-id $HOSTED_ZONE_ID \
        --change-batch file://failover-dns.json
}

# Main failover logic
main() {
    if ! check_health; then
        notify ":rotating_light: Primary CDE region unhealthy - initiating failover"

        failover_agents
        failover_db
        update_dns

        notify ":white_check_mark: Failover complete - CDE now running in $DR_REGION"
        notify ":robot_face: Agent tasks checkpointed and resuming in $DR_REGION"
    else
        echo "Primary region healthy - no action needed"
    fi
}

main "$@"