---
last_review: "2026-01-15"
last_reviewer: "Alexander Schlemmer"
documented_code: [ ]
---

```{tags} reference
```

# Environment variables

:::{note}
This new documentation page has not yet been fully reviewed and may be incomplete.
:::

When deploying LinkAhead with Docker Compose, these environment variables are used by Compose or
inside the containers:

## General settings

`LINKAHEAD_IMAGE`
: The Docker image used for the LinkAhead Java server.  
  **Default:** `indiscale/linkahead:0.16.0`

`LINKAHEAD_CONTAINER_NAME`
: The name of the Docker container running the LinkAhead server.  
  **Default:** `linkahead`

`COMPOSE_PROJECT_NAME`
: The name that identifies the Docker Compose setup. You can use this name to start and stop the
  Compose setup.  
  **Default:** `default`

`DEBUG`
: If `1`, the Java server runs in debug mode.  
  **Default:** `0`

`DOCKER_TZ`
: Defines the time zone in the Docker container, which is used by the LinkAhead server.  
  **Default:** `UTC`

`USERGROUP`
: The user and group (in `UID:GID` format) assigned to the LinkAhead server process.  
  **Default:** `999:999`

`DOCKER_MAIL`
: If `1`, enables sending mail.  
  **Default:** `0`

`SENDMAIL`
: The sendmail implementation to be used for sending mails. Typically `/usr/sbin/sendmail` or
  `/usr/local/bin/sendmail_to_file`.  
  **Default:** `/usr/sbin/sendmail`

% TODO: New email setup

## Authentication

`NIS_ENABLE`
: If `1`, enables NIS authentication.  
  **Default:** `0`

`NIS_DOMAIN`
: Specifies the NIS domain used for authentication. The domain can be acquired by running
  `ypdomainname`.  
  **Default:** `nis_domain`

`NIS_SERVER`
: Specifies the NIS server used for authentication. The server can be acquired by running
  `ypwhich`.  
  **Default:** `nis_server`

`LDAP_ENABLE`
: If `1`, enables LDAP authentication. In this case, a `nslcd.conf` file with correct configuration
  must be mounted into the container.  
  **Default:** `0`

`LOCAL_USERS`
: If `1`, users from the Docker host are available inside the Docker container.  
  **Default:** `0`

## Server configuration

The LinkAhead server can be configured via environment variables by prefixing the `server.conf`
options with `LINKAHEAD_CONFIG_`. See also the
[server configuration docs](/explanation/server/configuration.md) and
[https://gitlab.com/linkahead/linkahead-server/-/blob/main/conf/core/server.conf](https://gitlab.com/linkahead/linkahead-server/-/blob/main/conf/core/server.conf)

Example:

```
LINKAHEAD_CONFIG_AUTH_OPTIONAL=TRUE
```

## Network configuration

`BIND_IP`
: Defines which IP address the LinkAhead server binds to. An empty string (`""`) means it accepts
  connections from any IP.  
  **Default:** `127.0.0.1`

`NO_TLS`
: If `1`, disables TLS (SSL) in the LinkAhead server. **This might be insecure!**  
  **Default:** `0`

### Ports

`LA_PORT_SSL`
: The host port mapped to the internal SSL port of the LinkAhead server.  
  **Default:** `10443`

`LA_PORT_PLAIN`
: The host port mapped to the internal plain (non-SSL) HTTP port of the LinkAhead server.  
  **Default:** `8000`

`LA_PORT_DEBUG`
: The host port mapped to the Java debug interface of the LinkAhead server.  
  **Default:** `9000`

`LA_PORT_PROFILER`
: The host port mapped to the profiler interface of the LinkAhead server.  
  **Default:** `9090`

`LA_PORT_GRPC_SSL`
: The host port mapped to the internal gRPC SSL port of the LinkAhead server.  
  **Default:** `8443`

`LA_PORT_GRPC_PLAIN`
: The host port mapped to the internal plain gRPC port of the LinkAhead server.  
  **Default:** `8080`

### Proxy settings

`HTTP_PROXY`
: Optional proxy URL for HTTP connections.  
  **Default:** *(unset)*

`HTTPS_PROXY`
: Optional proxy URL for HTTPS connections.  
  **Default:** *(unset)*

`FTP_PROXY`
: Optional proxy URL for FTP connections.  
  **Default:** *(unset)*

`NO_PROXY`
: Optional comma-separated list of hosts or IPs that should bypass the proxy.  
  **Default:** *(unset)*

### Envoy

`ENVOY_PATH`
: Path to the `envoy.yaml` configuration file. If empty, a default configuration with sensible
  defaults is used.  
  **Default:** *(empty)*

`ENVOY_UID`
: The user ID of the Envoy proxy user.  
  **Default:** `987`

`ENVOY_PORT_PLAIN`
: Port for plain HTTP access via Envoy.  
  **Default:** `8081`

`ENVOY_PORT_SSL`
: Port for HTTPS access via Envoy.  
  **Default:** `10444`

:::{Note}
The following settings are defined inside the `envoy.yaml` file, not via environment variables:  
`ENVOY_CONNECT_TIMEOUT`, `ENVOY_ROUTE_TIMEOUT`.
:::

## Maintenance

`BACKUP_DIR`
: The directory used for storing and restoring backups.  
  **Default:** `backup`