[DOC] doc for examples (#2372)

[DOC] doc for examples

Summary of the Pull Request
Added doc
PR Checklist

 Refers to: #2370
 Documentation updated.

Reviewed-by: Aloento
Reviewed-by: Artem Lifshits
Reviewed-by: Vladimir Vshivkov

examples/README.md

@@ -0,0 +1,109 @@
+# Create a example for resources
+
+This example should match to next pattern:
+* Create folder for example, like `rds_instance_v3`
+
+  **NOTE:** Please use only underscores in folder names
+* Add this folder name in `runtime.yaml`, this file helps zuul job `otc-terraform-visualize-main` to process this example and run necessary checks.
+
+
+`runtime.yaml` content:
+```yaml
+---
+folders:
+- rds_instance_v3
+- elb_v3
+- autoscaling_with_elb_v3
+- autoscaling_with_alarm
+- nginx_app_on_compute_instance_v2
+- dns_zone_v2
+---
+```
+
+* Create `main.tf` and `settings.tf` inside created folder
+
+  `settings.tf` should contain main provider setup like:
+```hcl
+terraform {
+  required_providers {
+    opentelekomcloud = {
+      source  = "opentelekomcloud/opentelekomcloud"
+      version = ">= 1.35.9"
+    }
+  }
+}
+
+provider "opentelekomcloud" {
+  cloud = "functest_cloud"
+}
+```
+  and `main.tf` should contain the whole example
+
+    **NOTE:** you can create separate file for variables and outputs.
+
+`variables.tf`:
+```hcl
+variable "az" {
+  default = "eu-de-01"
+}
+```
+
+`outputs.tf`:
+```hcl
+output "db_id" {
+  value = opentelekomcloud_rds_instance_v3.instance.id
+}
+```
+
+`main.tf`
+```hcl
+module "network" {
+  source = "../modules/network"
+}
+
+resource "opentelekomcloud_rds_instance_v3" "instance" {
+  name              = "tf_rds_instance_1"
+  availability_zone = [var.az]
+  db {
+    password = "Postgres!120521"
+    type     = "PostgreSQL"
+    version  = "10"
+    port     = "8635"
+  }
+  security_group_id = module.network.default_security_group_id
+  subnet_id         = module.network.shared_subnet.network_id
+  vpc_id            = module.network.shared_subnet.vpc_id
+  volume {
+    type = "COMMON"
+    size = 40
+  }
+  flavor = "rds.pg.c2.large"
+  backup_strategy {
+    start_time = "08:00-09:00"
+    keep_days  = 0
+  }
+  tags = {
+    muh = "value-create"
+    kuh = "value-create"
+  }
+  lower_case_table_names = "0"
+}
+```
+
+ * Now all is done
+
+## Example Usage
+
+```shell
+terraform init
+terraform plan
+terraform apply
+terraform destroy
+```
+
+## Requirements
+
+| Name             | Version   |
+|------------------|-----------|
+| terraform        | >= 1.6.3  |
+| opentelekomcloud | >= 1.35.9 |

examples/rds_instance_v3/main.tf

@@ -3,8 +3,8 @@ module "network" {
 }
 
 resource "opentelekomcloud_rds_instance_v3" "instance" {
-  name              = "tf_rds_instance_%s"
-  availability_zone = ["%s"]
+  name              = "tf_rds_instance_1"
+  availability_zone = [var.az]
   db {
     password = "Postgres!120521"
     type     = "PostgreSQL"

examples/rds_instance_v3/variables.tf

@@ -0,0 +1,3 @@
+variable "az" {
+  default = "eu-de-01"
+}

releasenotes/notes/ex-doc-8a84f32fed8da581.yaml

@@ -0,0 +1,3 @@
+other:
+  - |
+    **[DOC]** Add doc for examples (`#2372 <https://github.com/opentelekomcloud/terraform-provider-opentelekomcloud/pull/2372>`_)