Infrastructure tutorials

Production-grade guides for Linux, servers, security and performance. Copy-paste commands, multi-distro support, written by engineers who run this in production.

linux Beginner

Fix apt update E: Repository no longer has a Release file

Learn why apt update fails with the Release file error on Ubuntu and Debian, how to find the broken repository entry, and how to fix it safely, including EOL releases and GPG key issues.

15 min 4 distros 12 views
linux Beginner

Fix PostgreSQL FATAL sorry, too many clients already

Learn why PostgreSQL throws FATAL: sorry, too many clients already, how to check and close idle connections, safely raise max_connections, and prevent the error from coming back with connection pooling.

20 min 4 distros 132 views
monitoring Advanced

Configure Logstash 8 security pipelines with threat intelligence enrichment

Build a production Logstash 8 pipeline that ingests firewall, IDS and syslog data, enriches events with MISP, AlienVault OTX and AbuseIPDB threat intel, and ships hardened IOC-enriched events to Elasticsearch.

75 min 4 distros 458 views
devops Advanced

Configure Ansible Vault integration with HashiCorp Vault for secrets management

Learn how to combine Ansible Vault with HashiCorp Vault using the community.hashi_vault collection, AppRole authentication, and least-privilege policies for production-grade secrets management in playbooks.

45 min 4 distros 570 views
monitoring Advanced

Set up Thanos Query and Compactor for distributed metrics querying

Deploy Thanos Sidecar, Query, and Compactor to unify multiple Prometheus instances into a single global query view with long-term S3-backed storage. Covers deduplication, TLS, and production troubleshooting.

75 min 4 distros 461 views
monitoring Advanced

Configure Kubernetes network monitoring with Hubble and Cilium for traffic visibility

Enable Hubble on Cilium to get real-time eBPF-based flow visibility, deploy Hubble UI and Relay, and integrate flow metrics with Prometheus and Grafana for full Kubernetes network observability.

75 min 4 distros 630 views
networking Advanced

Configure HAProxy with Consul for dynamic service discovery and automatic backend updates

Build a self-updating load balancer by integrating HAProxy with Consul service discovery, consul-template, and health checks so backends register and deregister automatically without manual reloads.

75 min 4 distros 584 views
security Advanced

Implement HAProxy WAF integration with ModSecurity 3 for advanced threat protection

Deploy ModSecurity 3 as a Stream Processing Offload Agent in front of HAProxy to inspect HTTP traffic with the OWASP Core Rule Set. This tutorial covers SPOA compilation, SPOE filter configuration, detection versus blocking modes, and production tuning.

75 min 4 distros 729 views
databases Advanced

Configure PostgreSQL 17 SSL encryption and certificate-based authentication

Set up a private CA, issue server and client certificates, enforce TLS 1.2+ with strong ciphers, and configure pg_hba.conf for mutual TLS client certificate authentication in PostgreSQL 17.

45 min 4 distros 838 views
networking Intermediate

Set up HAProxy SSL termination with Let's Encrypt certificates

Learn how to terminate SSL/TLS at HAProxy using Let's Encrypt certificates, redirect HTTP to HTTPS, automate renewal with deploy hooks, and harden your cipher suites for production load balancing.

35 min 4 distros 1,048 views
networking Advanced

Configure HAProxy with Consul for dynamic service discovery

Learn how to combine HAProxy, Consul and consul-template to build a self-updating load balancer that discovers backends automatically, reacts to health checks, and reloads without downtime.

50 min 4 distros 978 views
databases Intermediate

Configure PostgreSQL 17 connection pooling with PgBouncer for high availability

Deploy PgBouncer in front of PostgreSQL 17 with session, transaction and statement pooling modes, SCRAM-SHA-256 authentication, keepalived-based HA, and Prometheus monitoring for production workloads.

45 min 4 distros 973 views

Don't want to manage this yourself?

We handle infrastructure for businesses that depend on uptime. Fully managed, with one fixed contact who knows your setup.

You get one fixed contact who knows your setup

Rotterdam 15:14 · reachable in a message, no ticket form