NexaPG

NexaPG is a full-stack PostgreSQL monitoring platform for multiple remote targets. It combines FastAPI, React, and PostgreSQL in a Docker Compose stack with RBAC, polling collectors, query insights, alerting, and target-owner email notifications.

Highlights

• Multi-target monitoring for remote PostgreSQL instances
• PostgreSQL compatibility support: 14, 15, 16, 17, 18
• JWT auth (access + refresh) and RBAC (admin, operator, viewer)
• Polling collector for metrics, locks, activity, and optional pg_stat_statements
• Target detail overview (instance, storage, replication, core performance metrics)
• Alerts system:
  • standard built-in alerts
  • custom SQL alerts (admin/operator)
  • warning + alert severities
  • real-time UI updates + toast notifications
• Target owners: alert emails are sent only to responsible users assigned to a target
• SMTP settings in admin UI (send-only) with test mail support
• Structured backend logs + audit logs

Repository Layout

• backend/ FastAPI app, SQLAlchemy async models, Alembic migrations, collector services
• frontend/ React + Vite UI
• ops/ helper files/scripts
• docker-compose.yml full local stack
• .env.example complete environment template
• Makefile common commands

Prerequisites

• Docker Engine 24+
• Docker Compose v2+
• GNU Make (optional but recommended)
• Open host ports (or custom values in .env):
  • FRONTEND_PORT (default 5173)
  • BACKEND_PORT (default 8000)
  • DB_PORT (default 5433)

Optional:

• psql for manual DB checks

Quick Start

1. Copy environment template:

cp .env.example .env

2. Generate a Fernet key and set ENCRYPTION_KEY in .env:

python -c "from cryptography.fernet import Fernet; print(Fernet.generate_key().decode())"

3. Start the stack:

make up

4. Run migrations:

make migrate

5. Open the application:

• Frontend: http://<SERVER_IP>:<FRONTEND_PORT>
• API base: http://<SERVER_IP>:<BACKEND_PORT>/api/v1
• OpenAPI: http://<SERVER_IP>:<BACKEND_PORT>/docs

Initial admin bootstrap user (created from .env if missing):

• Email: value from INIT_ADMIN_EMAIL
• Password: value from INIT_ADMIN_PASSWORD

Make Commands

make up        # build and start all services
make down      # stop all services
make logs      # follow compose logs
make migrate   # run alembic upgrade head in backend container

Configuration Reference (.env)

Application

Variable	Description
APP_NAME	Application display name
ENVIRONMENT	Runtime environment (dev, staging, prod, test)
LOG_LEVEL	Backend log level (DEBUG, INFO, WARNING, ERROR)

Core Database

Variable	Description
DB_NAME	Core metadata database name
DB_USER	Core database user
DB_PASSWORD	Core database password
DB_PORT	Host port mapped to internal PostgreSQL 5432

Backend / Security

Variable	Description
BACKEND_PORT	Host port mapped to backend container port 8000
JWT_SECRET_KEY	JWT signing secret
JWT_ALGORITHM	JWT algorithm (default HS256)
JWT_ACCESS_TOKEN_MINUTES	Access token lifetime in minutes
JWT_REFRESH_TOKEN_MINUTES	Refresh token lifetime in minutes
ENCRYPTION_KEY	Fernet key for target credentials and SMTP password encryption
CORS_ORIGINS	Allowed CORS origins (comma-separated or * for dev only)
POLL_INTERVAL_SECONDS	Collector polling interval
INIT_ADMIN_EMAIL	Bootstrap admin email
INIT_ADMIN_PASSWORD	Bootstrap admin password

Alert Noise Tuning

Variable	Description
ALERT_ACTIVE_CONNECTION_RATIO_MIN_TOTAL_CONNECTIONS	Minimum total sessions required before evaluating active-connection ratio
ALERT_ROLLBACK_RATIO_WINDOW_MINUTES	Time window for rollback ratio evaluation
ALERT_ROLLBACK_RATIO_MIN_TOTAL_TRANSACTIONS	Minimum transaction volume before rollback ratio is evaluated
ALERT_ROLLBACK_RATIO_MIN_ROLLBACKS	Minimum rollback count before rollback ratio is evaluated

Frontend

Variable	Description
FRONTEND_PORT	Host port mapped to frontend container port 80
VITE_API_URL	Frontend API base URL (build-time)

Recommended values for VITE_API_URL:

• Reverse proxy setup: /api/v1
• Direct backend access: http://<SERVER_IP>:<BACKEND_PORT>/api/v1

Core Functional Areas

Targets

• Create, list, edit, delete targets
• Test target connection before save
• Configure SSL mode per target
• Toggle pg_stat_statements usage per target
• Assign responsible users (target owners)

Target Details

• Database Overview section with instance, role, uptime, size, replication, and core metrics
• Metric charts with range selection and live mode
• Locks and activity tables

Query Insights

• Uses collected pg_stat_statements data
• Ranking and categorization views
• Search and pagination
• Disabled automatically for targets where query insights flag is off

Alerts

• Warning and alert severity split
• Expandable alert cards with details and recommended actions
• Custom alert definitions (SQL + thresholds)
• Real-time refresh and in-app toast notifications

Admin Settings

• User management (RBAC)
• SMTP settings for outgoing alert mails:
  • enable/disable
  • host/port/auth
  • STARTTLS / SSL mode
  • from email + from name
  • recipient test mail

Target Owner Notifications

Email alert routing is target-specific:

• only users assigned as owners for a target receive that target's alert emails
• supports multiple owners per target
• notification sending is throttled to reduce repeated alert spam

API Overview

Health

• GET /api/v1/healthz
• GET /api/v1/readyz

Auth

• POST /api/v1/auth/login
• POST /api/v1/auth/refresh
• POST /api/v1/auth/logout
• GET /api/v1/me

Targets

• GET /api/v1/targets
• POST /api/v1/targets
• POST /api/v1/targets/test-connection
• GET /api/v1/targets/{id}
• PUT /api/v1/targets/{id}
• DELETE /api/v1/targets/{id}
• GET /api/v1/targets/{id}/owners
• PUT /api/v1/targets/{id}/owners
• GET /api/v1/targets/owner-candidates
• GET /api/v1/targets/{id}/metrics
• GET /api/v1/targets/{id}/locks
• GET /api/v1/targets/{id}/activity
• GET /api/v1/targets/{id}/top-queries
• GET /api/v1/targets/{id}/overview

Alerts

• GET /api/v1/alerts/status
• GET /api/v1/alerts/definitions
• POST /api/v1/alerts/definitions
• PUT /api/v1/alerts/definitions/{id}
• DELETE /api/v1/alerts/definitions/{id}
• POST /api/v1/alerts/definitions/test

Admin

• GET /api/v1/admin/users
• POST /api/v1/admin/users
• PUT /api/v1/admin/users/{user_id}
• DELETE /api/v1/admin/users/{user_id}
• GET /api/v1/admin/settings/email
• PUT /api/v1/admin/settings/email
• POST /api/v1/admin/settings/email/test

pg_stat_statements Requirement

Query Insights requires pg_stat_statements on the monitored target:

CREATE EXTENSION IF NOT EXISTS pg_stat_statements;

If unavailable, disable it per target in target settings.

Reverse Proxy / SSL Guidance

For production, serve frontend and API under the same public origin via reverse proxy.

• Frontend URL example: https://monitor.example.com
• Proxy API path /api/ to backend service
• Use VITE_API_URL=/api/v1

This prevents mixed-content and CORS issues.

PostgreSQL Compatibility Smoke Test

Run manually against one DSN:

PG_DSN='postgresql://postgres:postgres@127.0.0.1:5432/compatdb?sslmode=disable' \
python backend/scripts/pg_compat_smoke.py

Run with DSN candidates (CI style):

PG_DSN_CANDIDATES='postgresql://postgres:postgres@postgres:5432/compatdb?sslmode=disable,postgresql://postgres:postgres@127.0.0.1:5432/compatdb?sslmode=disable' \
python backend/scripts/pg_compat_smoke.py

Troubleshooting

Backend container keeps restarting during make migrate

Most common reason: failed migration. Check logs:

docker compose logs --tail=200 backend
docker compose logs --tail=200 db

CORS or mixed-content issues behind SSL proxy

• Set VITE_API_URL=/api/v1
• Ensure proxy forwards /api/ to backend
• Set correct frontend origin(s) in CORS_ORIGINS

rejected SSL upgrade for a target

Target likely does not support SSL with current settings. Set target sslmode to disable (or correct SSL config on target DB).

Query Insights empty

• Check target has Use pg_stat_statements enabled
• Verify extension exists on target (CREATE EXTENSION ...)

Security Notes

• No secrets hardcoded in repository
• Passwords hashed with Argon2
• Sensitive values encrypted at rest (Fernet)
• RBAC enforced on protected endpoints
• Audit logs for critical actions
• Collector error logging includes throttling to reduce repeated noise