docs(router): added documentation for env vars

packages/web/docs/src/content/router/configuration/_meta.ts

@@ -1,3 +1,4 @@
 export default {
   index: 'Overview',
+  'environment-variables': 'Environment Variables',
 };

packages/web/docs/src/content/router/configuration/environment-variables.mdx

@@ -0,0 +1,34 @@
+---
+title: 'Environment Variables'
+---
+
+# Environment Variables
+
+## Available Environment Variables
+
+The following environment variables are accepted by the router, and they override other
+configurations that can be set in the router's configuration file (`router.config.yaml`):
+
+| Name                     | Accepted Values                                      | Overrides (YAML)                                               |
+| ------------------------ | ---------------------------------------------------- | -------------------------------------------------------------- |
+| `LOG_LEVEL`              | `trace` / `debug` / `info` / `warn` / `error`        | [`log.level`](./log#level)                                     |
+| `LOG_FORMAT`             | `json` / `pretty-tree` / `pretty-compact`            | [`log.format`](./log#format)                                   |
+| `LOG_FILTER`             | `string`                                             | [`log.filter`](./log#filter)                                   |
+| `GRAPHIQL_ENABLED`       | `true` / `false`                                     | [`graphiql.enabled`](./graphiql#enabled)                       |
+| `PORT`                   | `number` (port number)                               | [`http.port`](./http#port)                                     |
+| `HOST`                   | `string` (host name or IP address)                   | [`http.host`](./http#host)                                     |
+| `SUPERGRAPH_FILE_PATH`   | `string` (relative or absolute path to a local file) | [`supergraph[file].path`](./supergraph#path)                   |
+| `HIVE_CDN_ENDPOINT`      | `string` (full url to Hive CDN supergraph artifact)  | [`supergraph[hive].endpoint`](./supergraph#endpoint)           |
+| `HIVE_CDN_KEY`           | `string` (Hive CDN key)                              | [`supergraph[hive].key`](./supergraph#key)                     |
+| `HIVE_CDN_POLL_INTERVAL` | `string` (human-readable, for example: `10s`)        | [`supergraph[hive].poll_interval`](./supergraph#poll_interval) |
+
+> In cases where a configuration file (`router.config.yaml`) is used with environment variables at
+> the same time, environment variables will only override the specific configuration values.
+
+## Additional Variables
+
+In addition, you may specify the following environment variables:
+
+| Name                      | Accepted Values                                      | Description                                          |
+| ------------------------- | ---------------------------------------------------- | ---------------------------------------------------- |
+| `ROUTER_CONFIG_FILE_PATH` | `string` (relative or absolute path to a local file) | Overrides the path to the router configuration file. |

packages/web/docs/src/content/router/configuration/graphiql.mdx

@@ -0,0 +1,17 @@
+---
+title: 'graphiql'
+---
+
+# graphiql
+
+The `graphiql` configuration object allows you to control the GraphiQL interface.
+
+## Options
+
+### `enabled`
+
+- **Type:** `boolean`
+- **Default:** `true`
+- **Environment Variable:** `GRAPHIQL_ENABLED`
+
+The `enabled` property controls whether the GraphiQL interface is enabled or disabled.

packages/web/docs/src/content/router/configuration/http.mdx

@@ -13,6 +13,7 @@ Router listens on for incoming GraphQL requests.
 
 - **Type:** `string`
 - **Default:** `"0.0.0.0"`
+- **Environment Variable:** `HOST`
 
 The `host` property specifies the IP address to which the router's HTTP server will bind.
 
@@ -25,6 +26,7 @@ The `host` property specifies the IP address to which the router's HTTP server w
 
 - **Type:** `integer`
 - **Default:** `4000`
+- **Environment Variable:** `PORT`
 
 The `port` property specifies the network port that the router will listen on. Ensure this port is
 not already in use by another service on the same host. When running in a container, this is the

packages/web/docs/src/content/router/configuration/index.mdx

@@ -7,6 +7,9 @@ title: 'Configuration reference'
 You can configure Hive Router using a YAML, JSON, or TOML file (by default, `router.config.yaml`).
 We'll use YAML for all examples in this documentation since it's the most readable.
 
+Some configuration variables can be overridden at runtime using
+[environment variables](./environment-variables).
+
 This page covers all the main configuration options available. Each option links to a detailed page
 that explains how to use that feature.
 

packages/web/docs/src/content/router/configuration/log.mdx

@@ -16,6 +16,7 @@ You can control the verbosity, format, and filtering of the logs generated by th
 
 - **Type:** `string`
 - **Default:** `info`
+- **Environment Variable:** `LOG_LEVEL`
 
 The `level` property controls the verbosity of the logs. By default, the router is configured to be
 mostly silent at the `info` level, emitting only important operational messages, warnings, and
@@ -33,6 +34,7 @@ The available log levels, from most verbose to least, are:
 
 - **Type:** `string`
 - **Default:** `json`
+- **Environment Variable:** `LOG_FORMAT`
 
 The `format` property determines the structure of the log output.
 
@@ -47,6 +49,7 @@ The `format` property determines the structure of the log output.
 ### `filter`
 
 - **Type:** `string`
+- **Environment Variable:** `LOG_FILTER`
 
 The `filter` property provides advanced, fine-grained control over which log messages are emitted
 based on their origin (e.g., a specific module within the router) and their level. This can be used

packages/web/docs/src/content/router/configuration/supergraph.mdx

@@ -24,6 +24,7 @@ Load the Supergraph schema from [Hive Console](../../schema-registry) CDN.
 
 - **Type:** `string`
 - **Required:** Yes
+- **Environment Variable:** `HIVE_CDN_ENDPOINT`
 
 The [_Hive CDN Endpoint_](../../schema-registry/get-started/apollo-federation#cdn-access) of your
 target.
@@ -39,6 +40,7 @@ supergraph:
 
 - **Type:** `string`
 - **Required:** Yes
+- **Environment Variable:** `HIVE_CDN_KEY`
 
 The [_Hive CDN key/token_](../../schema-registry/management/targets#creating-a-cdn-access-token) of
 your target.
@@ -55,6 +57,7 @@ supergraph:
 - **Type:** `string`
 - **Required:** No
 - **Default:** `10s`
+- **Environment Variable:** `HIVE_CDN_POLL_INTERVAL`
 
 A human-readable string representing the interval at which the router should poll Hive CDN for
 changes.
@@ -114,6 +117,7 @@ Load the schema from a local file.
 
 - **Type:** `string`
 - **Required:** Yes
+- **Environment Variable:** `SUPERGRAPH_FILE_PATH`
 
 Path to your supergraph schema file. Can be absolute or relative to where you're running the router.