Added Modules generation (cycloidio#164)

CHANGELOG.md

@@ -1,5 +1,10 @@
 ## [Unreleased]
 
+### Added
+
+- Ability to create Modules directly when importing
+  ([Issue #141](https://github.com/cycloidio/terracognita/issues/141))
+
 ## [0.6.0] _2020-12-22_
 
 ### Added

README.md

@@ -87,6 +87,59 @@ clean:                           Removes binary and/or docker image
 
 [![asciicast](https://asciinema.org/a/330055.svg)](https://asciinema.org/a/330055)
 
+### Modules
+
+Terracognita can generate Terraform Modules directly when importing. To enable this feature you'll need to use the `--module {module/path/name}` and then on that specific path is where the module will be generated. The path has to be directory or a none existent path (it'll be created), the content of the path will be deleted (after user confirmation) so we can have a clean import.
+
+The output structure will look like (having `--module test`) this where each file aggregates the resources from the same "category":
+
+```
+test/
+├── module-test
+│   ├── autoscaling.tf
+│   ├── cloud_front.tf
+│   ├── cloud_watch.tf
+│   ├── ec2.tf
+│   ├── elastic_load_balancing_v2_alb_nlb.tf
+│   ├── iam.tf
+│   ├── rds.tf
+│   ├── route53_resolver.tf
+│   ├── route53.tf
+│   ├── s3.tf
+│   ├── ses.tf
+│   └── variables.tf
+└── module.tf
+```
+
+By default all the attributes will be changed for variables, those variables will then be on the `module-{name}/variables.tf` and exposed on the `module.tf` like so:
+
+```hcl
+module "test" {
+  # aws_instance_front_instance_type = "t2.small"
+  [...]
+  source = "module-test"
+}
+```
+
+If you want to change this behavior, as for big infrastructures this will create a lot of variables, you can use the `--module-varibles path/to/file` and the file will have the list of attributes that you want to actually be used as variables, it can be in JSON or YAML:
+
+```json
+{
+  "aws_instance": [
+    "instance_type",
+    "cpu_threads_per_core",
+    "cpu_core_count"
+  ]
+}
+```
+
+```yaml
+aws_instance:
+  - instance_type
+  - cpu_threads_per_core
+  - cpu_core_count
+```
+
 ### Docker
 
 You can use directly [the image built](https://hub.docker.com/r/cycloid/terracognita), or you can build your own.

cmd/aws.go

@@ -29,8 +29,11 @@ var (
 		Use:   "aws",
 		Short: "Terracognita reads from AWS and generates hcl resources and/or terraform state",
 		Long:  "Terracognita reads from AWS and generates hcl resources and/or terraform state",
-		PreRun: func(cmd *cobra.Command, args []string) {
-			preRunEOutput(cmd, args)
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			err := preRunEOutput(cmd, args)
+			if err != nil {
+				return err
+			}
 
 			viper.BindPFlag("aws-access-key", cmd.Flags().Lookup("aws-access-key"))
 			viper.BindPFlag("aws-secret-access-key", cmd.Flags().Lookup("aws-secret-access-key"))
@@ -47,6 +50,8 @@ var (
 			viper.RegisterAlias("secret-key", "aws-secret-access-key")
 			viper.RegisterAlias("session-token", "aws-session-token")
 			viper.RegisterAlias("region", "aws-default-region")
+
+			return nil
 		},
 		PostRunE: postRunEOutput,
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -85,7 +90,10 @@ var (
 			}
 
 			var hclW, stateW writer.Writer
-			options := &writer.Options{Interpolate: viper.GetBool("interpolate")}
+			options, err := getWriterOptions()
+			if err != nil {
+				return err
+			}
 
 			if hclOut != nil {
 				logger.Log("msg", "initializing HCL writer")

cmd/azurerm.go

@@ -23,14 +23,19 @@ var (
 		Use:   "azurerm",
 		Short: "Terracognita reads from Azure and generates hcl resources and/or terraform state",
 		Long:  "Terracognita reads from Azure and generates hcl resources and/or terraform state",
-		PreRun: func(cmd *cobra.Command, args []string) {
-			preRunEOutput(cmd, args)
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			err := preRunEOutput(cmd, args)
+			if err != nil {
+				return err
+			}
 			viper.BindPFlag("client-id", cmd.Flags().Lookup("client-id"))
 			viper.BindPFlag("client-secret", cmd.Flags().Lookup("client-secret"))
 			viper.BindPFlag("environment", cmd.Flags().Lookup("environment"))
 			viper.BindPFlag("resource-group-name", cmd.Flags().Lookup("resource-group-name"))
 			viper.BindPFlag("subscription-id", cmd.Flags().Lookup("subscription-id"))
 			viper.BindPFlag("tenant-id", cmd.Flags().Lookup("tenant-id"))
+
+			return nil
 		},
 		PostRunE: postRunEOutput,
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -65,7 +70,10 @@ var (
 			}
 
 			var hclW, stateW writer.Writer
-			options := &writer.Options{Interpolate: viper.GetBool("interpolate")}
+			options, err := getWriterOptions()
+			if err != nil {
+				return err
+			}
 
 			if hclOut != nil {
 				logger.Log("msg", "initializing HCL writer")

cmd/google.go

@@ -25,13 +25,18 @@ var (
 		Use:   "google",
 		Short: "Terracognita reads from GCP and generates hcl resources and/or terraform state",
 		Long:  "Terracognita reads from GCP and generates hcl resources and/or terraform state",
-		PreRun: func(cmd *cobra.Command, args []string) {
-			preRunEOutput(cmd, args)
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			err := preRunEOutput(cmd, args)
+			if err != nil {
+				return err
+			}
 			viper.BindPFlag("credentials", cmd.Flags().Lookup("credentials"))
 			viper.BindPFlag("project", cmd.Flags().Lookup("project"))
 			viper.BindPFlag("region", cmd.Flags().Lookup("region"))
 			viper.BindPFlag("labels", cmd.Flags().Lookup("labels"))
 			viper.BindPFlag("max-results", cmd.Flags().Lookup("max-results"))
+
+			return nil
 		},
 		PostRunE: postRunEOutput,
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -73,7 +78,10 @@ var (
 			}
 
 			var hclW, stateW writer.Writer
-			options := &writer.Options{Interpolate: viper.GetBool("interpolate")}
+			options, err := getWriterOptions()
+			if err != nil {
+				return err
+			}
 
 			if hclOut != nil {
 				logger.Log("msg", "initializing HCL writer")