Fix Frontend Observability App import (#2155)

* feat(fe-o11y): Add Frontend Observability App Import

This commit adds support to import existing apps into Terraform

Closes: #2115

* fix(feo11y): Fix Frontend Observbility App Update Inconsistency

This commit fixes an issue where the collector endpoint would not be
populated correctly when updating an App. This was happening because
Frontend Observbility API will not return the collector URL on app
update.

Author: kpelelis

docs/index.md

@@ -262,6 +262,29 @@ provider "grafana" {
 }
 ```
 
+#### Import existing Frontend Observability apps into Terraform
+
+To manage an existing Frontend Observability app with Terraform, you can import it into your Terraform state.
+
+##### Before you begin
+
+You will need the following:
+
+- **Stack slug** – This is the first part of your Grafana Cloud URL. For example, in `https://mystack.grafana.net`, the stack slug is `mystack`.
+
+- **App ID** – Navigate to the app in your Grafana Cloud instance and copy the ID from the URL. It will look like this: `https://<stack-slug>.grafana.net/a/grafana-kowalski-app/apps/<app-id>`
+
+
+##### Import command
+
+Run the following command to import the app into your Terraform state:
+
+```bash
+terraform import '<stack-slug>:<app-id>' my-app
+```
+
+Replace <stack-slug> and <app-id> with the appropriate values for your environment.
+
 <!-- schema generated by tfplugindocs -->
 ## Schema
 

internal/resources/frontendo11y/resource_frontend_o11y_app.go

@@ -5,6 +5,8 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strconv"
+	"strings"
 
 	"github.com/hashicorp/terraform-plugin-framework-validators/mapvalidator"
 	"github.com/hashicorp/terraform-plugin-framework-validators/stringvalidator"
@@ -25,6 +27,9 @@ import (
 var (
 	resourceFrontendO11yAppName        = "grafana_frontend_o11y_app"
 	resourceFrontendO11yAppTerraformID = common.NewResourceID(common.StringIDField("stack_id"), common.StringIDField("name"))
+
+	// Check interface
+	_ resource.ResourceWithImportState = (*resourceFrontendO11yApp)(nil)
 )
 
 type resourceFrontendO11yApp struct {
@@ -135,6 +140,22 @@ func (r *resourceFrontendO11yApp) getStackCluster(ctx context.Context, stackID s
 	return stack.ClusterSlug, nil
 }
 
+func (r *resourceFrontendO11yApp) getStack(ctx context.Context, stackID string) (*gcom.FormattedApiInstance, error) {
+	stack, res, err := r.gcomClient.InstancesAPI.GetInstance(ctx, stackID).Execute()
+	if err != nil {
+		return nil, err
+	}
+
+	if res.StatusCode >= 500 {
+		return nil, errors.New("server error")
+	}
+
+	if res.StatusCode == http.StatusNotFound {
+		return nil, fmt.Errorf("stack %q not found", stackID)
+	}
+	return stack, nil
+}
+
 func (r *resourceFrontendO11yApp) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) {
 	var dataTF FrontendO11yAppTFModel
 	diags := req.Plan.Get(ctx, &dataTF)
@@ -163,6 +184,42 @@ func (r *resourceFrontendO11yApp) Create(ctx context.Context, req resource.Creat
 	resp.State.Set(ctx, appTFState)
 }
 
+func (r *resourceFrontendO11yApp) ImportState(ctx context.Context, req resource.ImportStateRequest, resp *resource.ImportStateResponse) {
+	reqParts := strings.Split(req.ID, ":")
+	if len(reqParts) != 2 {
+		resp.Diagnostics.AddError("incorrect ID format", "Resource ID should be in the format of 'stackID:appID'")
+		return
+	}
+	stackSlug := reqParts[0]
+	appID := reqParts[1]
+	i64AppID, err := strconv.ParseInt(appID, 10, 64)
+	if err != nil {
+		resp.Diagnostics.AddError("invalid app ID", err.Error())
+		return
+	}
+
+	stack, err := r.getStack(ctx, stackSlug)
+	if err != nil {
+		resp.Diagnostics.AddError("failed to get Grafana Cloud Stack information", err.Error())
+		return
+	}
+	appClientModel, err := r.client.GetApp(
+		ctx,
+		apiURLForCluster(stack.ClusterSlug, r.client.Host()),
+		int64(stack.Id),
+		i64AppID,
+	)
+
+	if err != nil {
+		resp.Diagnostics.AddError("failed to get frontend o11y app", err.Error())
+		return
+	}
+
+	clientTFData, diags := convertClientModelToTFModel(int64(stack.Id), appClientModel)
+	resp.Diagnostics.Append(diags...)
+	resp.State.Set(ctx, clientTFData)
+}
+
 func (r *resourceFrontendO11yApp) Read(ctx context.Context, req resource.ReadRequest, resp *resource.ReadResponse) {
 	var dataTF FrontendO11yAppTFModel
 	diags := req.State.Get(ctx, &dataTF)
@@ -221,6 +278,7 @@ func (r *resourceFrontendO11yApp) Update(ctx context.Context, req resource.Updat
 	}
 
 	appTFState, diags := convertClientModelToTFModel(dataTF.StackID.ValueInt64(), appClientModel)
+	appTFState.CollectorEndpoint = dataTF.CollectorEndpoint
 	resp.Diagnostics.Append(diags...)
 	resp.State.Set(ctx, appTFState)
 }

templates/index.md.tmpl

@@ -55,6 +55,29 @@ provider "grafana" {
 }
 ```
 
+#### Import existing Frontend Observability apps into Terraform
+
+To manage an existing Frontend Observability app with Terraform, you can import it into your Terraform state.
+
+##### Before you begin
+
+You will need the following:
+
+- **Stack slug** – This is the first part of your Grafana Cloud URL. For example, in `https://mystack.grafana.net`, the stack slug is `mystack`.
+
+- **App ID** – Navigate to the app in your Grafana Cloud instance and copy the ID from the URL. It will look like this: `https://<stack-slug>.grafana.net/a/grafana-kowalski-app/apps/<app-id>`
+
+
+##### Import command
+
+Run the following command to import the app into your Terraform state:
+
+```bash
+terraform import '<stack-slug>:<app-id>' my-app
+```
+
+Replace <stack-slug> and <app-id> with the appropriate values for your environment.
+
 {{ .SchemaMarkdown | trimspace }}
 
 ### Managing Cloud Provider