feat(provider): add profile name from configuration file support (scaleway#875)

* feat(provider): add profile name from configuration file support

* feat(provider): enhance error handling

* chore(provider): add section about new profile feature usage

* fix(provider): fix condition

* Apply suggestions from code review

Co-authored-by: jaime Bernabe <[email protected]>

Author: alexandrebouthinon

docs/index.md

@@ -178,6 +178,38 @@ If it fails to detect credentials inline, or in the environment, Terraform will
 You can optionally specify a different location with `SCW_CONFIG_PATH` environment variable.
 You can find more information about this configuration [in the documentation](https://github.com/scaleway/scaleway-sdk-go/blob/master/scw/README.md#scaleway-config).
 
+This method also supports a `profile` configuration:
+
+Example:
+
+If your shared configuration file contains:
+
+```yaml
+profiles:
+  myProfile:
+    access_key: xxxxxxxxxxxxxxxxxxxx
+    secret_key: xxxxxxxx-xxx-xxxx-xxxx-xxxxxxxxxxx
+    default_organization_id: xxxxxxxx-xxx-xxxx-xxxx-xxxxxxxxxxx 
+    default_project_id: xxxxxxxx-xxx-xxxx-xxxx-xxxxxxxxxxx
+    default_zone: fr-par-2
+    default_region: fr-par
+    api_url: https://api.scaleway.com
+    insecure: false
+```
+
+You can invoke and use this profile in the provider declaration:
+
+```hcl
+provider "scaleway" {
+  alias   = "p2"
+  profile = "myProfile"
+}
+
+resource "scaleway_instance_ip" "server_ip" {
+  provider = scaleway.p2
+}
+```
+
 ## Arguments Reference
 
 In addition to [generic provider arguments](https://www.terraform.io/docs/configuration/providers.html) (e.g. `alias` and `version`), the following arguments are supported in the Scaleway provider block:

scaleway/provider.go

@@ -39,6 +39,11 @@ func Provider(config *ProviderConfig) plugin.ProviderFunc {
 					Description:  "The Scaleway secret Key.",
 					ValidateFunc: validationUUID(),
 				},
+				"profile": {
+					Type:        schema.TypeString,
+					Optional:    true, // To allow user to use `access_key`, `secret_key`, `project_id`...
+					Description: "The Scaleway profile to use.",
+				},
 				"project_id": {
 					Type:         schema.TypeString,
 					Optional:     true, // To allow user to use organization instead of project
@@ -230,6 +235,12 @@ func loadProfile(d *schema.ResourceData) (*scw.Profile, error) {
 
 	providerProfile := &scw.Profile{}
 	if d != nil {
+		if profileName, exist := d.GetOk("profile"); exist {
+			profileFromConfig, err := config.GetProfile(profileName.(string))
+			if err == nil {
+				providerProfile = profileFromConfig
+			}
+		}
 		if accessKey, exist := d.GetOk("access_key"); exist {
 			providerProfile.AccessKey = scw.StringPtr(accessKey.(string))
 		}