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Flybug Notes

Practical notes on Linux, networks, backend services, and small tools.
Linux Service Checklist
Small repeatable checks for services and ports.
TLS Notes
Certificate renewal and verification habits.
SQLite Tools
Why small tools can stay simple.
A small checklist for Linux services

When a service is down, the first five minutes should be boring. A short checklist keeps the investigation grounded.

Check the unit

systemctl status my-service --no-pager -l
Flybug7/7/26Less than 1 minuteLinuxsystemdoperationschecklist
Systemd logs I check first

journalctl is one of the fastest ways to understand what a small server is doing.

Recent service logs

journalctl -u my-service --since "30 minutes ago" --no-pager
Flybug7/6/26Less than 1 minuteLinuxjournalctltroubleshooting
Keeping TLS certificates boring

TLS certificates should be quiet infrastructure. They only become interesting when renewal fails.

Check DNS first

Before issuing a certificate, confirm the domain points to the expected host:

dig example.com A
Flybug7/5/26Less than 1 minuteNetworkTLScertificatescertbot
Reverse proxy notes I keep coming back to

Reverse proxies are simple in diagrams and detailed in production.

Forwarded headers

Most applications need the original host, scheme, and client address:

Host
X-Forwarded-For
X-Forwarded-Proto
Flybug7/4/26Less than 1 minuteNetworkreverse-proxyhttpheaders
Why SQLite is enough for many internal tools

SQLite is often treated as a prototype database, but it is a very practical choice for many internal tools.

What it makes easy

  • A single file is simple to back up.
  • There is no database service to operate.
  • SQL is still available.
  • Local development matches production surprisingly well for small workloads.
Flybug7/3/26Less than 1 minuteToolsSQLitebackenddata
Observability basics for small systems

Small systems do not need a huge monitoring stack to become easier to operate. They need a few consistent signals.

Logs

Logs should answer what happened, when it happened, and which request or job was involved.

Metrics

Start with request count, error count, latency, queue length, process memory, and disk usage.

Flybug7/2/26Less than 1 minuteToolsobservabilitylogsmetrics
About

Flybug Notes is a compact technical notebook about small production systems.

The site focuses on Linux operations, backend habits, networking details, and tools that keep servers easier to understand.

FlybugLess than 1 minute