Added terraform example

Author: antonbabenko

README.md

@@ -1,4 +1,4 @@
-# tfvars-annotations - Update values in terraform.tfvars using annotations
+# Update values in terraform.tfvars using annotations
 
 ### This is still WIP, full of bugs, missing core features and docs.
 
@@ -8,7 +8,7 @@ As of today, Terraform 0.11 and 0.12 support only static (known, fixed, already
 
 While working on [modules.tf](https://github.com/antonbabenko/modules.tf-lambda) (a tool which converts visual diagrams created with [Cloudcraft.co](https://cloudcraft.co/) into Terraform configurations), I had a need to generate code which would chain invocations of [Terraform AWS modules](https://github.com/terraform-aws-modules) and pass arguments between them without requiring any extra Terraform code as a glue. [Terragrunt](https://github.com/gruntwork-io/terragrunt) is a great fit for this, it allows to reduce amount of Terraform configurations by reusing Terraform modules and providing arguments as values in `tfvars` files.
 
-Some languages I know have concepts like annotations and decorators, so at first I made a [shell script](https://github.com/antonbabenko/modules.tf-lambda/blob/v1.2.0/templates/terragrunt-common-layer/common/scripts/update_dynamic_values_in_tfvars.sh) which replaced values in `tfvars` based on annotations and was called by Terragrunt hooks. `tfvars-annotations` shares the same goal and it has no external dependencies.
+Some languages I know have concepts like annotations and decorators, so at first I made a [shell script](https://github.com/antonbabenko/modules.tf-lambda/blob/v1.2.0/templates/terragrunt-common-layer/common/scripts/update_dynamic_values_in_tfvars.sh) which replaced values in `tfvars` based on annotations and was called by Terragrunt hooks. `tfvars-annotations` shares the same goal and it has no external dependencies (except `terraform` or `terragrunt`).
 
 
 ## Use cases
@@ -24,6 +24,17 @@ Some languages I know have concepts like annotations and decorators, so at first
   - [ ] terraform_output
   - [ ] data-sources generic
 
+## How to use
+
+Run `tfvars-annotations` before `terraform plan, apply, refresh`.
+
+It will process tfvars file in the current directory and set updated values.
+
+E.g.:
+
+    $ tfvars-annotations update
+    $ terraform plan
+ 
 ## How to disable processing entirely
 
 Put `@modulestf:disable_values_updates` anywhere in the `terraform.tfvars` to not process the file.

examples/project1/eu-west-1/app/.terragrunt-cache/zeG_zjs3hFlERLTSSOGADBcQIxQ/AoKn_3NNiOJEg4PmxaP5wYFi3M8/.terraform/main.tf renamed to examples/project1-terragrunt/eu-west-1/app/.terragrunt-cache/zeG_zjs3hFlERLTSSOGADBcQIxQ/AoKn_3NNiOJEg4PmxaP5wYFi3M8/.terraform/main.tf

@@ -0,0 +1,11 @@
+# @ modulestf:disable_values_updates
+
+vpc_id = "vpc-443a8116aae25c7e9" # @modulestf:terraform_output.vpc.vpc_id
+
+public_subnets = ["subnet-297e8b509d8aeebfe","subnet-3f831847e5802071c","subnet-6c6f959a9063d32b2"] # @modulestf:terraform_output.vpc.public_subnets
+
+something = "" # @modulestf:terraform_output.something.id
+
+vpc4_id = "vpc-443a8116aae25c7e9" # @modulestf:terraform_output.vpc.vpc_id
+
+the end!

examples/project1/eu-west-1/app/.terragrunt-cache/zeG_zjs3hFlERLTSSOGADBcQIxQ/AoKn_3NNiOJEg4PmxaP5wYFi3M8/.terraform/terraform.tfvars renamed to examples/project1-terragrunt/eu-west-1/app/.terragrunt-cache/zeG_zjs3hFlERLTSSOGADBcQIxQ/AoKn_3NNiOJEg4PmxaP5wYFi3M8/.terraform/terraform.tfvars

@@ -0,0 +1,9 @@
+{
+    "sensitive": false,
+    "type": "list",
+    "value": [
+        "subnet-297e8b509d8aeebfe",
+        "subnet-3f831847e5802071c",
+        "subnet-6c6f959a9063d32b2"
+    ]
+}

examples/project1/eu-west-1/app/terraform.tfvars renamed to examples/project1-terragrunt/eu-west-1/app/terraform.tfvars

@@ -0,0 +1,5 @@
+{
+    "sensitive": false,
+    "type": "string",
+    "value": "vpc-443a8116aae25c7e9"
+}