Split up environment variable documentation between cli and dockerd

This creates a new section of environment variables in the CLI docs
which documents environment variables that can both be used on dockerd
and on docker cli.

In addition, it moves some of the environment variable documentation
from the docker cli documentation to the dockerd documentation, as
these environment variables are dockerd-specific.

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit ad301e74102fc028d6b4137038528ab6b03bb6b1)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Upstream-commit: 8b8ec04cd6adaedf178ad269a4dc0e6ab647d3e9
Component: cli

Author: sargun

components/cli/docs/reference/commandline/cli.md

@@ -61,27 +61,27 @@ by the `docker` command line:
 
 * `DOCKER_API_VERSION` The API version to use (e.g. `1.19`)
 * `DOCKER_CONFIG` The location of your client configuration files.
-* `DOCKER_CERT_PATH` The location of your authentication keys.
 * `DOCKER_CLI_EXPERIMENTAL` Enable experimental features for the cli (e.g. `enabled` or `disabled`)
-* `DOCKER_DRIVER` The graph driver to use.
 * `DOCKER_HOST` Daemon socket to connect to.
-* `DOCKER_NOWARN_KERNEL_VERSION` Prevent warnings that your Linux kernel is
-  unsuitable for Docker.
-* `DOCKER_RAMDISK` If set this will disable 'pivot_root'.
 * `DOCKER_STACK_ORCHESTRATOR` Configure the default orchestrator to use when using `docker stack` management commands.
-* `DOCKER_TLS` When set Docker uses TLS.
-* `DOCKER_TLS_VERIFY` When set Docker uses TLS and verifies the remote.
 * `DOCKER_CONTENT_TRUST` When set Docker uses notary to sign and verify images.
   Equates to `--disable-content-trust=false` for build, create, pull, push, run.
 * `DOCKER_CONTENT_TRUST_SERVER` The URL of the Notary server to use. This defaults
   to the same URL as the registry.
 * `DOCKER_HIDE_LEGACY_COMMANDS` When set, Docker hides "legacy" top-level commands (such as `docker rm`, and
   `docker pull`) in `docker help` output, and only `Management commands` per object-type (e.g., `docker container`) are
   printed. This may become the default in a future release, at which point this environment-variable is removed.
-* `DOCKER_TMPDIR` Location for temporary Docker files.
 * `DOCKER_CONTEXT` Specify the context to use (overrides DOCKER_HOST env var and default context set with "docker context use")
 * `DOCKER_DEFAULT_PLATFORM` Specify the default platform for the commands that take the `--platform` flag.
 
+#### Shared Environment variables
+
+These environment variables can be used both with the `docker` command line and
+`dockerd` command line:
+
+* `DOCKER_CERT_PATH` The location of your authentication keys.
+* `DOCKER_TLS_VERIFY` When set Docker uses TLS and verifies the remote.
+
 Because Docker is developed using Go, you can also use any environment
 variables used by the Go runtime. In particular, you may find these useful:
 

components/cli/docs/reference/commandline/dockerd.md

@@ -117,6 +117,17 @@ the `daemon.json` file.
 > Enable experimental features by starting `dockerd` with the `--experimental`
 > flag or adding `"experimental": true` to the `daemon.json` file.
 
+### Environment variables
+
+For easy reference, the following list of environment variables are supported
+by the `dockerd` command line:
+
+* `DOCKER_DRIVER` The graph driver to use.
+* `DOCKER_NOWARN_KERNEL_VERSION` Prevent warnings that your Linux kernel is
+  unsuitable for Docker.
+* `DOCKER_RAMDISK` If set this will disable 'pivot_root'.
+* `DOCKER_TMPDIR` Location for temporary Docker files.
+
 ## Examples
 
 ### Daemon socket option