Update apply CLI docs

Primarly,

1. Emphasize on the new '-c' flag, removing '-f'.
2. Adding related commands
3. Clarifying the use cases for apply

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

cmd/apply.go

@@ -60,8 +60,8 @@ func init() {
 }
 
 var applyCmd = &cobra.Command{
-	Use:   "apply [env-name] [-f <file-or-dir>]",
-	Short: `Apply local configuration to remote cluster`,
+	Use:   "apply <env-name>",
+	Short: `Apply local Kubernetes manifests to remote clusters`,
 	RunE: func(cmd *cobra.Command, args []string) error {
 		if len(args) != 1 {
 			return fmt.Errorf("'apply' requires an environment name; use `env list` to see available environments\n\n%s", cmd.UsageString())
@@ -121,29 +121,46 @@ var applyCmd = &cobra.Command{
 
 		return c.Run(objs, wd)
 	},
-	Long: `Update (or optionally create) Kubernetes resources on the cluster using the
-local configuration. Use the` + " `--create` " + `flag to control whether we create them
-if they do not exist (default: true).
+	Long: `
+Update (or optionally create) Kubernetes resources on the cluster using your
+local Kubernetes manifests. Use the` + " `--create` " + `flag to control whether
+they are created if they do not exist (default: true).
 
-ksonnet applications are accepted, as well as normal JSON, YAML, and Jsonnet
-files.`,
-	Example: `# Create or update all resources described in a ksonnet application, and
-# running in the 'dev' environment. Can be used in any subdirectory of the
-# application.
-ks apply dev
+The local Kubernetes manifests that are applied reside in your ` + "`components/`" + `
+directory. When applied, the manifests are fully expanded using the paremeters
+of the specified environment.
+
+By default, all manifests are applied. To apply a subset of manifests, use the
+` + "`--component` " + `flag, as seen in the examples below.
 
-# Create or update resources described in a YAML file. Automatically picks up
-# the cluster's location from '$KUBECONFIG'.
-ks appy -f ./pod.yaml
+### Related Commands
 
-# Create or update resources described in the JSON file. Changes are deployed
-# to the cluster pointed at the 'dev' environment.
-ks apply dev -f ./pod.json
+* ` + "`ks delete` " + `— Delete the component manifests on your cluster
 
-# Update resources described in a YAML file, and running in cluster referred
-# to by './kubeconfig'.
-ks apply --kubeconfig=./kubeconfig -f ./pod.yaml
+### Syntax
+`,
+	Example: `
+# Create or update all resources described in a ksonnet application, and
+# running in the 'dev' environment. Can be used in any subdirectory of the
+# application.
+#
+# This is equivalent to applying all components in the 'components/' directory.
+ks apply dev
 
-# Display set of actions we will execute when we run 'apply'.
-ks apply dev --dry-run`,
+# Create or update the single resource 'guestbook-ui' described in a ksonnet
+# application, and running in the 'dev' environment. Can be used in any
+# subdirectory of the application.
+#
+# This is equivalent to applying the component with the same file name (excluding
+# the extension) 'guestbook-ui' in the 'components/' directory.
+ks apply dev -c guestbook-ui
+
+# Create or update the multiple resources, 'guestbook-ui' and 'nginx-depl'
+# described in a ksonnet application, and running in the 'dev' environment. Can
+# be used in any subdirectory of the application.
+#
+# This is equivalent to applying the component with the same file name (excluding
+# the extension) 'guestbook-ui' and 'nginx-depl' in the 'components/' directory.
+ks apply dev -c guestbook-ui -c nginx-depl
+`,
 }

docs/cli-reference/ks.md

@@ -14,7 +14,7 @@ Synchronise Kubernetes resources with config files
 ```
 
 ### SEE ALSO
-* [ks apply](ks_apply.md)	 - Apply local configuration to remote cluster
+* [ks apply](ks_apply.md)	 - Apply local Kubernetes manifests to remote clusters
 * [ks delete](ks_delete.md)	 - Delete Kubernetes resources described in local config
 * [ks diff](ks_diff.md)	 - Display differences between server and local config, or server and server config
 * [ks env](ks_env.md)	 - Manage ksonnet environments

docs/cli-reference/ks_apply.md

 ## ks apply
 
-Apply local configuration to remote cluster
+Apply local Kubernetes manifests to remote clusters
 
 ### Synopsis
 
 
-Update (or optionally create) Kubernetes resources on the cluster using the
-local configuration. Use the `--create` flag to control whether we create them
-if they do not exist (default: true).
 
-ksonnet applications are accepted, as well as normal JSON, YAML, and Jsonnet
-files.
+Update (or optionally create) Kubernetes resources on the cluster using your
+local Kubernetes manifests. Use the `--create` flag to control whether
+they are created if they do not exist (default: true).
+
+The local Kubernetes manifests that are applied reside in your `components/`
+directory. When applied, the manifests are fully expanded using the paremeters
+of the specified environment.
+
+By default, all manifests are applied. To apply a subset of manifests, use the
+`--component` flag, as seen in the examples below.
+
+### Related Commands
+
+* `ks delete` — Delete the component manifests on your cluster
+
+### Syntax
+
 
 ```
-ks apply [env-name] [-f <file-or-dir>]
+ks apply <env-name>
 ```
 
 ### Examples
 
 ```
+
 # Create or update all resources described in a ksonnet application, and
 # running in the 'dev' environment. Can be used in any subdirectory of the
 # application.
+#
+# This is equivalent to applying all components in the 'components/' directory.
 ks apply dev
 
-# Create or update resources described in a YAML file. Automatically picks up
-# the cluster's location from '$KUBECONFIG'.
-ks appy -f ./pod.yaml
-
-# Create or update resources described in the JSON file. Changes are deployed
-# to the cluster pointed at the 'dev' environment.
-ks apply dev -f ./pod.json
-
-# Update resources described in a YAML file, and running in cluster referred
-# to by './kubeconfig'.
-ks apply --kubeconfig=./kubeconfig -f ./pod.yaml
+# Create or update the single resource 'guestbook-ui' described in a ksonnet
+# application, and running in the 'dev' environment. Can be used in any
+# subdirectory of the application.
+#
+# This is equivalent to applying the component with the same file name (excluding
+# the extension) 'guestbook-ui' in the 'components/' directory.
+ks apply dev -c guestbook-ui
+
+# Create or update the multiple resources, 'guestbook-ui' and 'nginx-depl'
+# described in a ksonnet application, and running in the 'dev' environment. Can
+# be used in any subdirectory of the application.
+#
+# This is equivalent to applying the component with the same file name (excluding
+# the extension) 'guestbook-ui' and 'nginx-depl' in the 'components/' directory.
+ks apply dev -c guestbook-ui -c nginx-depl
 
-# Display set of actions we will execute when we run 'apply'.
-ks apply dev --dry-run
 ```
 
 ### Options