Primary cmd help message.

cmd/vault-handler/vault_handler.go

@@ -12,8 +12,46 @@ import (
 
 var rootCmd = &cobra.Command{
 	Use:   "vault-handler",
-	Short: "",
-	Long:  ``,
+	Short: "Hashicorp-Vault companion, to upload/download contents from Vault based on a manifest.",
+	Long: `
+#
+# vault-handler
+#
+
+Hashicorp-Vault companion to upload and download secrets. It can be used as a Kubernetes
+init-container or a command-line application, where you can define manifest files to define how
+secrets are placed in Vault, corresponding how secret-files are organized in the file-system.
+
+## Environment Variables
+
+Command-line arguments can be expressed inline, or by exporting environment variables. For
+example, the argument "--vault-addr" becomes "VAULT_HANDLER_VAULT_ADDR" in environment. Note the
+prefix "VAULT_HANDLER_" in front of the actual argument value, also the capitalization and
+replacement of dashes ("-") by underscores ("_").
+
+## Manifest Files
+
+YAML based manifest files are the last argument in "vault-handler" command-line. They represent the
+layout of files in the file-system, and will drive the reflection of this data in Vault. Please
+consider the GitHub project page for manifest documentation:
+
+	https://github.com/otaviof/vault-handler
+
+## Example
+
+First you may want to export configuration in the environment:
+
+	$ export VAULT_HANDLER_VAULT_ADDR="http://127.0.0.1:8200"
+	$ export VAULT_HANDLER_VAULT_ROLE_ID="role-id"
+	$ export VAULT_HANDLER_VAULT_SECRET_ID="secret-id"
+
+And later call "vault-handler" with additional arguments, and the manifest files:
+
+	$ vault-handler upload --input-dir /var/tmp --dry-run /path/to/manifest.yaml
+	$ vault-handler download --output-dir /tmp --dry-run /path/to/manifest.yaml
+
+## Command-Line
+`,
 }
 
 // configFromEnv creates a configuration object using Viper, which brings overwritten values from