Specifying client config.json with Bazel label (#2032)

* Specifying client config.json with Bazel label

* regenerate stardoc

README.md

@@ -1255,6 +1255,12 @@ docker_toolchain_configure(
   client_config="/path/to/docker/client/config",
 )
 
+# Alternatively, specify the Bazel label for the config.json
+docker_toolchain_configure(
+  name = "docker_config",
+  client_config="@//path/to/docker/client:config.json",
+)
+
 # Load the custom version of container_pull created by the docker toolchain
 # configuration.
 load("@docker_config//:pull.bzl", authenticated_container_pull="container_pull")

container/pull.bzl

@@ -48,7 +48,8 @@ _container_pull_attrs = {
         doc = "The digest of the image to pull.",
     ),
     "docker_client_config": attr.string(
-        doc = """Specifies a custom directory to look for the docker client configuration.
+        doc = """Specifies a custom directory to look for the docker client configuration, or a Bazel label of
+            the config.json file.
 
             Don't use this directly.
             Instead, specify the docker configuration directory using a custom docker toolchain configuration.
@@ -170,8 +171,11 @@ def _impl(repository_ctx):
     ]
 
     # Use the custom docker client config directory if specified.
-    if repository_ctx.attr.docker_client_config != "":
-        args += ["-client-config-dir", "{}".format(repository_ctx.attr.docker_client_config)]
+    docker_client_config = repository_ctx.attr.docker_client_config
+    if docker_client_config.startswith("@") or docker_client_config.startswith("//"):
+        args += ["-client-config-dir", repository_ctx.path(Label(docker_client_config)).dirname]
+    elif docker_client_config:
+        args += ["-client-config-dir", docker_client_config]
 
     cache_dir = repository_ctx.os.environ.get("DOCKER_REPO_CACHE")
     if cache_dir:

docs/container.md

@@ -197,7 +197,7 @@ please use the bazel startup flag `--loading_phase_threads=1` in your bazel invo
 | <a id="container_pull-architecture"></a>architecture |  Which CPU architecture to pull if this image refers to a multi-platform manifest list, default 'amd64'.   | String | optional | "amd64" |
 | <a id="container_pull-cpu_variant"></a>cpu_variant |  Which CPU variant to pull if this image refers to a multi-platform manifest list.   | String | optional | "" |
 | <a id="container_pull-digest"></a>digest |  The digest of the image to pull.   | String | optional | "" |
-| <a id="container_pull-docker_client_config"></a>docker_client_config |  Specifies a custom directory to look for the docker client configuration.<br><br>            Don't use this directly.             Instead, specify the docker configuration directory using a custom docker toolchain configuration.             Look for the <code>client_config</code> attribute in <code>docker_toolchain_configure</code>             [here](https://github.com/bazelbuild/rules_docker#setup) for details.             See [here](https://github.com/bazelbuild/rules_docker#container_pull-custom-client-configuration)             for an example on how to use container_pull after configuring the docker toolchain<br><br>            When left unspecified (ie not set explicitly or set by the docker toolchain),             docker will use the directory specified via the <code>DOCKER_CONFIG</code> environment variable.<br><br>            If <code>DOCKER_CONFIG</code> isn't set, docker falls back to <code>$HOME/.docker</code>.   | String | optional | "" |
+| <a id="container_pull-docker_client_config"></a>docker_client_config |  Specifies a custom directory to look for the docker client configuration, or a Bazel label of             the config.json file.<br><br>            Don't use this directly.             Instead, specify the docker configuration directory using a custom docker toolchain configuration.             Look for the <code>client_config</code> attribute in <code>docker_toolchain_configure</code>             [here](https://github.com/bazelbuild/rules_docker#setup) for details.             See [here](https://github.com/bazelbuild/rules_docker#container_pull-custom-client-configuration)             for an example on how to use container_pull after configuring the docker toolchain<br><br>            When left unspecified (ie not set explicitly or set by the docker toolchain),             docker will use the directory specified via the <code>DOCKER_CONFIG</code> environment variable.<br><br>            If <code>DOCKER_CONFIG</code> isn't set, docker falls back to <code>$HOME/.docker</code>.   | String | optional | "" |
 | <a id="container_pull-import_tags"></a>import_tags |  Tags to be propagated to generated rules.   | List of strings | optional | [] |
 | <a id="container_pull-os"></a>os |  Which os to pull if this image refers to a multi-platform manifest list.   | String | optional | "linux" |
 | <a id="container_pull-os_features"></a>os_features |  Specifies os features when pulling a multi-platform manifest list.   | List of strings | optional | [] |

toolchains/docker/toolchain.bzl

@@ -68,8 +68,8 @@ docker_toolchain = rule(
         ),
         "client_config": attr.string(
             default = "",
-            doc = "A custom directory for the docker client config.json. If " +
-                  "DOCKER_CONFIG is not specified, the value of the " +
+            doc = "A custom directory or a Bazel label for the docker client config.json. " +
+                  "If DOCKER_CONFIG is not specified, the value of the " +
                   "DOCKER_CONFIG environment variable will be used. " +
                   "DOCKER_CONFIG is not defined, the home directory will be " +
                   "used.",
@@ -189,7 +189,7 @@ toolchain_configure = repository_rule(
         ),
         "client_config": attr.string(
             mandatory = False,
-            doc = "A custom directory for the docker client " +
+            doc = "A custom directory or a Bazel label for the docker client" +
                   "config.json. If DOCKER_CONFIG is not specified, the value " +
                   "of the DOCKER_CONFIG environment variable will be used. " +
                   "DOCKER_CONFIG is not defined, the default set for the " +