Table of Contents

Environment Variables

Validation rules

Known-bad-values block list
JWT secret length rule

System logging
Embedded workers
Request profiling (Pyinstrument)
API server
Ingester batching
Web dashboard
Tracing (OpenTelemetry)
Database
CORS
Starter .env.local
Notes

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Environment Variables

DECNET reads configuration from process environment. On import, decnet/env.py loads .env.local first (preferred, git-ignored) then .env from the project root. Any variable already present in the shell environment wins over both files.

Only the variables listed below are recognised. Anything else is noise.

Source of truth: decnet/env.py
Starter template: env.config.example

See also: DB drivers, Logging, Systemd, Tracing.

Validation rules

Two validators live in decnet/env.py:

_port(name, default) — integer in [1, 65535]. Applies to DECNET_API_PORT, DECNET_WEB_PORT, DECNET_DB_PORT.
_require_env(name) — variable must be set, and must not be a known-bad default. Under pytest (PYTEST* env var present) the bad-value check is skipped so test fixtures can use sentinel values.

Known-bad-values block list

_require_env rejects these case-insensitive literals:

admin
secret
password
changeme
fallback-secret-key-change-me

JWT secret length rule

When name == "DECNET_JWT_SECRET", the value must be at least 32 bytes. This matches HS256's minimum key length (RFC 7518 §3.2 — "A key of the same size as the hash output [...] or larger MUST be used"). The check is relaxed when DECNET_DEVELOPER=true.

System logging

Name	Type	Default	Required	Consequence
`DECNET_SYSTEM_LOGS`	path	`decnet.system.log`	No	Destination for the RFC 5424 `RotatingFileHandler` installed by `decnet/config.py`. All microservice daemons (api, sniffer, profiler, collector) append here. Skipped under pytest.

Embedded workers

These are escape hatches — leave them unset in normal deployments. decnet deploy always spawns standalone daemons, and embedding the same worker inside the API duplicates DB writes and sniffer packets.

Name	Type	Default	Required	Consequence
`DECNET_EMBED_PROFILER`	bool (`true`/other)	`false`	No	Embed profiler in API process. Do not combine with `decnet profiler --daemon`.
`DECNET_EMBED_SNIFFER`	bool	`false`	No	Embed MACVLAN sniffer in API process. Do not combine with `decnet sniffer --daemon`.

Request profiling (Pyinstrument)

Name	Type	Default	Required	Consequence
`DECNET_PROFILE_REQUESTS`	bool	`false`	No	Mount Pyinstrument ASGI middleware on the FastAPI app. Writes per-request HTML flamegraphs.
`DECNET_PROFILE_DIR`	path	`profiles`	No	Output directory for flamegraphs. Relative paths are relative to `$PWD`.

API server

Name	Type	Default	Required	Consequence
`DECNET_API_HOST`	str	`127.0.0.1`	No	Bind address for the FastAPI server.
`DECNET_API_PORT`	int (1–65535)	`8000`	No	TCP port for the API.
`DECNET_JWT_SECRET`	str (≥32 chars)	—	Yes	HS256 signing secret. Missing, known-bad, or short values abort startup unless `DECNET_DEVELOPER=true` (and even then, known-bad is still rejected).
`DECNET_INGEST_LOG_FILE`	path	`/var/log/decnet/decnet.log`	No	File the ingester tails for honeypot events.

Ingester batching

Name	Type	Default	Required	Consequence
`DECNET_BATCH_SIZE`	int	`100`	No	Rows accumulated per DB commit. Larger batches reduce SQLite write-lock contention.
`DECNET_BATCH_MAX_WAIT_MS`	int	`250`	No	Maximum milliseconds to wait before flushing a partial batch. Bounds latency during idle periods.

Web dashboard

Name	Type	Default	Required	Consequence
`DECNET_WEB_HOST`	str	`127.0.0.1`	No	Bind address for the web dashboard.
`DECNET_WEB_PORT`	int (1–65535)	`8080`	No	Web dashboard port.
`DECNET_ADMIN_USER`	str	`admin`	No*	Admin login. `admin` is a known-bad default and is rejected at startup outside pytest.
`DECNET_ADMIN_PASSWORD`	str	`admin`	No*	Admin password. Rejected if set to a known-bad value. Change both.
`DECNET_DEVELOPER`	bool	`false`	No	`true` enables DEBUG logging and relaxes the JWT length check. Does not enable tracing.

*The defaults exist so imports do not crash, but the web API refuses to start with them in non-pytest environments.

Tracing (OpenTelemetry)

Independent from DECNET_DEVELOPER so tracing can be toggled on its own.

Name	Type	Default	Required	Consequence
`DECNET_DEVELOPER_TRACING`	bool	`false`	No	Enable OpenTelemetry tracing for the API and workers.
`DECNET_OTEL_ENDPOINT`	URL	`http://localhost:4317`	No	OTLP gRPC collector endpoint.

See Tracing and Profiling.

Database

See Database Drivers for the full driver matrix.

Name	Type	Default	Required	Consequence
`DECNET_DB_TYPE`	`sqlite` \| `mysql`	`sqlite`	No	Selects the repository subclass. Lower-cased automatically.
`DECNET_DB_URL`	SQLAlchemy URL	unset	No	Full URL, e.g. `mysql+asyncmy://user:pass@host:3306/decnet`. When set, all component vars below are ignored.
`DECNET_DB_HOST`	str	`localhost`	No	MySQL host.
`DECNET_DB_PORT`	int (1–65535)	`3306`	No	MySQL port. Validated only when explicitly set.
`DECNET_DB_NAME`	str	`decnet`	No	Database name.
`DECNET_DB_USER`	str	`decnet`	No	DB user.
`DECNET_DB_PASSWORD`	str	unset	No	DB password. `None` when unset.

CORS

Name	Type	Default	Required	Consequence
`DECNET_CORS_ORIGINS`	CSV of URLs	`http://<web_host>:<web_port>`	No	Allowed origins for the dashboard API. Wildcard bind addresses (`0.0.0.0`, `127.0.0.1`, `::`) resolve to `localhost` in the default.

Example override:

DECNET_CORS_ORIGINS=http://192.168.1.50:9090,https://dashboard.example.com

Starter `.env.local`

Copy this to the project root as .env.local, change every placeholder, and keep it out of git.

# System logging
DECNET_SYSTEM_LOGS=decnet.system.log

# Embedded workers (leave off unless you know why)
DECNET_EMBED_PROFILER=false
DECNET_EMBED_SNIFFER=false

# Request profiling
DECNET_PROFILE_REQUESTS=false
DECNET_PROFILE_DIR=profiles

# API
DECNET_API_HOST=127.0.0.1
DECNET_API_PORT=8000
# Generate with:  python -c 'import secrets; print(secrets.token_urlsafe(48))'
DECNET_JWT_SECRET=REPLACE_WITH_A_64_BYTE_URLSAFE_TOKEN_NOT_IN_THE_BAD_LIST
DECNET_INGEST_LOG_FILE=/var/log/decnet/decnet.log

# Ingester batching
DECNET_BATCH_SIZE=100
DECNET_BATCH_MAX_WAIT_MS=250

# Web dashboard
DECNET_WEB_HOST=127.0.0.1
DECNET_WEB_PORT=8080
DECNET_ADMIN_USER=anti
DECNET_ADMIN_PASSWORD=REPLACE_ME_WITH_A_LONG_PASSPHRASE
DECNET_DEVELOPER=false

# Tracing
DECNET_DEVELOPER_TRACING=false
DECNET_OTEL_ENDPOINT=http://localhost:4317

# Database (sqlite is the default; uncomment the mysql block to switch)
DECNET_DB_TYPE=sqlite
# DECNET_DB_TYPE=mysql
# DECNET_DB_URL=mysql+asyncmy://decnet:REPLACE_ME@db.internal:3306/decnet
# DECNET_DB_HOST=db.internal
# DECNET_DB_PORT=3306
# DECNET_DB_NAME=decnet
# DECNET_DB_USER=decnet
# DECNET_DB_PASSWORD=REPLACE_ME

# CORS (only needed when the browser is not on the same host:port as the API)
# DECNET_CORS_ORIGINS=http://192.168.1.50:9090,https://dashboard.example.com

Notes

decnet/config.py re-reads DECNET_DEVELOPER and DECNET_SYSTEM_LOGS during logging setup. Those are the same variables documented above — there are no others.

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DECNET — honeypot deception-network framework. Pre-1.0, active development — use with caution. See Sponsors to support the project. Contact: samuel@securejump.cl