Guide

Environment Variables

Ze reads environment variables for daemon-wide knobs (pprof, PID file, privilege drop) and BGP protocol tuning. Every variable has a matching YANG path under the environment { } config block; the OS env var wins when both are set.

See environment.md for the authoritative list.

Priority

OS environment variable (shell, systemd EnvironmentFile, container runtime)
Config file environment { ... } block
Built-in default

An OS env var is never overwritten by a config value.

Common Variables

Variable	Purpose
`ze.user`	User to drop to after binding privileged ports
`ze.pid.file`	Path to PID file written at startup, removed at clean shutdown
`ze.pprof`	Bind pprof HTTP server (e.g. `:6060`). Empty disables
`ze.bgp.openwait`	Seconds to wait for peer OPEN after TCP connect
`ze.bgp.announce.delay`	Duration to block between reactor Ready and first UPDATE
`exabgp.api.ack`	ExaBGP bridge: emit `done`/`error` ack lines on plugin stdin

Config Block Syntax

The same knobs can be expressed in the config file:

environment {
    daemon {
        pid "/run/ze.pid"
        user "zeuser"
    }
    bgp {
        openwait 60
        announce-delay 5s
    }
    pprof ":6060"
    exabgp {
        api {
            ack false
        }
    }
    chaos {
        seed 0
        rate "0.1"
    }
    reactor {
        cache-ttl 60
    }
    log {
        level INFO
        bgp.routes debug
    }
}

Discoverability

Shell completion offers env-key suggestions after ze env get and ze env registered using canonical dot-form keys. Concrete ze.log.<subsystem> keys (visible in ze env list) are completable and inspectable via ze env get.

In the interactive CLI operational mode, show env get and show env registered also offer env-key completion through the shared command tree.

Changes in 2026-04

The ExaBGP compatibility surface was trimmed. Every ze.bgp.daemon.*, ze.bgp.log.*, ze.bgp.tcp.*, ze.bgp.api.*, and ze.bgp.debug.* variable was either renamed, dropped, or plumbed from a YANG leaf to a new env key:

Old	New / Action
`ze.bgp.daemon.pid`	Plumbed to `ze.pid.file` (YANG leaf kept)
`ze.bgp.daemon.user`	Plumbed to `ze.user` (YANG leaf kept)
`ze.bgp.daemon.daemonize`, `drop`, `umask`	Dropped (use systemd unit file)
`ze.bgp.log.level`, `destination`, `short`	Dropped (slogutil owns `ze.log.*`)
`ze.bgp.tcp.attempts`	Dropped (test harness sends SIGTERM)
`ze.bgp.tcp.delay`	Dropped; new `ze.bgp.announce.delay` duration
`ze.bgp.tcp.port`	Renamed `ze.test.bgp.port` (test infrastructure only)
`ze.bgp.tcp.acl`	Dropped (experimental, unimplemented)
`ze.bgp.bgp.openwait`	Renamed `ze.bgp.openwait`
`ze.bgp.cache.attributes`	Dropped (caching is architectural)
`ze.bgp.debug.pprof`	Renamed `ze.pprof` (process-wide)
`ze.bgp.debug.*` (pdb/memory/rotate/etc.)	Dropped (use `go tool pprof`, `ze.log`)
`ze.bgp.api.ack`	Dropped; `exabgp.api.ack` handles bridge ack
`ze.bgp.api.chunk`, `encoder`, `respawn`, ...	Dropped (Ze manages plugins)

The ze exabgp migrate --env tool converts surviving keys to Ze YANG blocks and emits # <key> -- no longer supported comments for dropped ones so an operator can audit an ExaBGP env file before commit.