Merge pull request #2 from kishaningithub/update-documentation

Update readme documentation

README.md

@@ -1,8 +1,140 @@
 # tf-import-gen (Terraform import generator)
 
+[![Build Status](https://github.com/kishaningithub/tf-import-gen/actions/workflows/build.yml/badge.svg)](https://github.com/kishaningithub/tf-import-gen/actions/workflows/build.yml)
+[![Go Report Card](https://goreportcard.com/badge/github.com/kishaningithub/tf-import-gen)](https://goreportcard.com/report/github.com/kishaningithub/tf-import-gen)
+[![Latest release](https://img.shields.io/github/release/kishaningithub/tf-import-gen.svg)](https://github.com/kishaningithub/tf-import-gen/releases)
+
 Tool to generate terraform import statements to simplify state migrations from one terraform code base to another.
 
+<!-- TOC -->
+* [tf-import-gen (Terraform import generator)](#tf-import-gen-terraform-import-generator)
+  * [Installation](#installation)
+    * [Using Homebrew](#using-homebrew)
+    * [Using docker](#using-docker)
+    * [Others](#others)
+  * [Examples](#examples)
+    * [Generating import statements by module](#generating-import-statements-by-module)
+    * [Generating import statements by resource](#generating-import-statements-by-resource)
+    * [Generating import statements for all resources](#generating-import-statements-for-all-resources)
+  * [Usage](#usage)
+  * [Contributing](#contributing)
+<!-- TOC -->
+
+## Installation
+
+### Using Homebrew
+
+```bash
+brew install kishaningithub/tap/tf-import-gen
+```
+
+### Using docker
+
+pulling the image
+```bash
+docker pull ghcr.io/kishaningithub/tf-import-gen:0.1.0
+```
+
+running the image in interactive mode (volume mounted aws folder for config)
+```bash
+docker run -it -v "${HOME}/.aws:/root/.aws" ghcr.io/kishaningithub/tf-import-gen:0.1.0
+```
+
+### Others
+
+Head over to the [releases page](https://github.com/kishaningithub/tf-import-gen/releases) and download a binary for your platform
+
+## Examples
+
+### Generating import statements by module
+
+```bash
+$ terraform show -json | tf-import-gen module.example
+
+import {
+  to = module.example.aws_glue_catalog_database.example_db
+  id = "123456789012:example_db"
+}
+
+import {
+  to = module.example.aws_iam_instance_profile.example_instance_profile
+  id = "example_instance_profile"
+}
+```
+
+### Generating import statements by resource
+
+```bash
+$ terraform show -json | tf-import-gen aws_instance.example
+
+import {
+  to = aws_instance.example
+  id = "i-123456789012"
+}
+```
+
+### Generating import statements for all resources
+
+```bash
+$ terraform show -json | tf-import-gen
+
+import {
+  to = module.example.aws_glue_catalog_database.example_db
+  id = "123456789012:example_db"
+}
+
+import {
+  to = module.example.aws_iam_instance_profile.example_instance_profile
+  id = "example_instance_profile"
+}
+
+import {
+  to = aws_instance.example
+  id = "i-123456789012"
+}
+```
+
+## Usage
+
+```bash
+$ tf-import-gen --help
+
+Generate terraform import statements to simplify state migrations from one terraform code base to another.
+
+The address argument can be used to filter the instances by resource or module. If
+no pattern is given, import statements are generated for all the resources.
+
+The addresses must either be module addresses or absolute resource
+addresses, such as:
+  aws_instance.example
+  module.example
+  module.example.module.child
+  module.example.aws_instance.example
+
+Usage:
+  tf-import-gen [flags] address
+
+Examples:
+
+## Generating import statements by module
+terraform show -json | tf-import-gen module.example
+
+## Generating import statements by resource
+terraform show -json | tf-import-gen aws_instance.example
+
+## Generating import statements for all resources
+terraform show -json | tf-import-gen
+
+
+Flags:
+  -h, --help      help for tf-import-gen
+  -v, --version   version for tf-import-gen
+```
+
+
+## Contributing
 
+PRs are always welcome!. Refer [CONTRIBUTING.md](./CONTRIBUTING.md) for more information
 
 
 

main.go

@@ -5,16 +5,39 @@ import (
 	"github.com/kishaningithub/tf-import-gen/pkg"
 	"github.com/spf13/cobra"
 	"os"
+	"strings"
 )
 
 var Version = "dev"
 
 func main() {
 	var rootCmd = &cobra.Command{
-		Use:     "tf-import-gen",
-		Short:   "Generate terraform import statements",
-		Long:    "Tool to generate terraform import statements to simplify state migrations from one terraform code base to another",
+		Use:   "tf-import-gen [flags] address",
+		Short: "Generate terraform import statements",
+		Long: strings.TrimSpace(`
+Generate terraform import statements to simplify state migrations from one terraform code base to another.
+
+The address argument can be used to filter the instances by resource or module. If
+no pattern is given, import statements are generated for all the resources.
+
+The addresses must either be module addresses or absolute resource
+addresses, such as:
+  aws_instance.example
+  module.example
+  module.example.module.child
+  module.example.aws_instance.example
+`),
 		Version: Version,
+		Example: `
+## Generating import statements by module
+terraform show -json | tf-import-gen module.example
+
+## Generating import statements by resource
+terraform show -json | tf-import-gen aws_instance.example
+
+## Generating import statements for all resources
+terraform show -json | tf-import-gen
+`,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			address := ""
 			if len(os.Args) > 1 {