Environment variables - Lasso

Environment Variables Reference

Core

Variable	Required	Description	Default
`SECRET_KEY_BASE`	Prod	Phoenix signing secret (64+ bytes)	-
`PHX_HOST`	Recommended in prod	Public hostname for generated URLs	`localhost`
`PHX_SCHEME`	No	External URL scheme	`https` in production
`PHX_SERVER`	No	Set to `true` to enable the HTTP server when the endpoint configuration does not already enable it; production enables it by default	-
`PORT`	No	HTTP listener port	`4000`
`LASSO_NODE_ID`	Prod	Unique node identifier	`"local"` in dev
`LASSO_DATA_DIR`	No	Base directory for profiles and snapshots	`/data` in Docker; unset outside Docker
`LASSO_PROFILES_DIR`	No	Profile YAML directory; overrides the data directory	`config/profiles` outside Docker
`LASSO_SNAPSHOTS_DIR`	No	Snapshot directory, selected at runtime	`priv/benchmark_snapshots` outside Docker
`LASSO_VM_METRICS_ENABLED`	No	Set to `true` to enable VM metrics	`false`
`LASSO_COWBOY_TELEMETRY_ENABLED`	No	Set to `false` to disable Cowboy per-request telemetry; Lasso application and dashboard events remain enabled	`true`
`LASSO_HTTP_RESPONSE_HEAP_TUNING_ENABLED`	No	Use a larger short-lived heap while validating completed HTTP upstream responses; benchmark before enabling for latency-bound traffic	`false`
`LASSO_HTTP_POOL_SIZE`	No	Maximum HTTP/1 connections per upstream host and pool	`256`
`LASSO_HTTP_POOL_COUNT`	No	Independent Finch pools per upstream host	`1`

Clustering

Variable	Required	Description
`CLUSTER_DNS_QUERY`	For clustering	DNS name for node discovery
`CLUSTER_NODE_BASENAME`	For clustering	Erlang distribution node basename
`RELEASE_DISTRIBUTION`	For clustering	Set to `name` for long node names
`RELEASE_NODE`	For clustering	`<basename>@<reachable-private-IP>`
`RELEASE_COOKIE`	Release/container	Private distribution secret; identical across cluster members

Provider Keys

Any ${VAR_NAME} in profile YAML is resolved from environment variables at startup.

Environment changes require a process restart or container recreation. YAML reload reads the environment of the running process. See Docker deployment.

Block continuity

Global mode requires LASSO_BLOCK_PUBLICATION_DATABASE_URL, LASSO_BLOCK_PUBLICATION_MEMBERS, and a unique stable LASSO_NODE_ID on every serving instance. Ordinary routing needs no database. Follow the complete journal and fleet setup before enabling it.