scout: add information about cli env vars

Signed-off-by: David Karlsson <35727626+dvdksn@users.noreply.github.com>

content/scout/env-vars.md

@@ -0,0 +1,40 @@
+---
+title: Environment variables used by Docker Scout
+linkTitle: Docker Scout environment variables
+description: Configure how the behavior of Docker Scout CLI commands using these environment variables
+keywords: scout, supply chain, cli, env, variables, configure
+---
+
+The following environment variables are available to configure the Docker Scout
+CLI commands, and the corresponding `docker/scout-cli` container image:
+
+| Name                                    | Format  | Description                                                                                 |
+| :-------------------------------------- | ------- | :------------------------------------------------------------------------------------------ |
+| DOCKER_SCOUT_CACHE_FORMAT               | String  | Format of the local image cache; can be `oci` or `tar` (default: `oci`)                     |
+| DOCKER_SCOUT_CACHE_DIR                  | String  | Directory where the local SBOM cache is stored (default: `$HOME/.docker/scout`)             |
+| DOCKER_SCOUT_NO_CACHE                   | Boolean | When set to `true`, disables the use of local SBOM cache                                    |
+| DOCKER_SCOUT_OFFLINE                    | Boolean | Use [offline mode](#offline-mode) when indexing SBOM                                        |
+| DOCKER_SCOUT_REGISTRY_TOKEN             | String  | Token for authenticating to a registry when pulling images                                  |
+| DOCKER_SCOUT_REGISTRY_USER              | String  | Username for authenticating to a registry when pulling images                               |
+| DOCKER_SCOUT_REGISTRY_PASSWORD          | String  | Password or personal access token for authenticating to a registry when pulling images      |
+| DOCKER_SCOUT_HUB_USER                   | String  | Docker Hub username for authenticating to the Docker Scout backend                          |
+| DOCKER_SCOUT_HUB_PASSWORD               | String  | Docker Hub password or personal access token for authenticating to the Docker Scout backend |
+| DOCKER_SCOUT_NEW_VERSION_WARN           | Boolean | Warn about new versions of the Docker Scout CLI                                             |
+| DOCKER_SCOUT_EXPERIMENTAL_WARN          | Boolean | Warn about experimental features                                                            |
+| DOCKER_SCOUT_EXPERIMENTAL_POLICY_OUTPUT | Boolean | Disable experimental output for policy evaluation                                           |
+
+## Offline mode
+
+Under normal operation, Docker Scout cross-references external systems, such as
+npm, NuGet, or proxy.golang.org, to retrieve additional information about
+packages found in your image.
+
+When `DOCKER_SCOUT_OFFLINE` is set to `true`, Docker Scout image analysis runs
+in offline mode. Offline mode means Docker Scout doesn't make outbound requests
+to external systems.
+
+To use offline mode:
+
+```console
+$ export DOCKER_SCOUT_OFFLINE=true
+```

data/toc.yaml

@@ -1362,6 +1362,8 @@ Manuals:
         title: Analyze local files
       - path: /scout/sbom/
         title: SBOM
+      - path: /scout/env-vars/
+        title: Environment variables
     - sectiontitle: Policy Evaluation
       section:
       - path: /scout/policy/