Onboard object storage credentials group (#74)

* Onboard credentials group resource

* Update object storage acc test

* Fix typo

* Generate docs, add examples, fix typos

* Refactor map fiels

* Add unit test for readCredentialsGroups

* Fix lint issues§
g

* Use projectId from Model

* Fix errors§
g

* Fix test

* Simplify signature of enableProject

* Change comment

* Add TestEnableProject

* Rename variable

* Add enableProject test

* Remove unused test setting

* Fix wrong error message

* Improve test case, rename mocked data

* Fix typo

* Removed unnecessary test case

* Removed unnecessary test case

---------

Co-authored-by: Henrique Santos <henrique.santos@freiheit.com>

stackit/internal/services/objectstorage/credentialsgroup/datasource.go

@@ -0,0 +1,144 @@
+package objectstorage
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hashicorp/terraform-plugin-framework/datasource"
+	"github.com/hashicorp/terraform-plugin-framework/schema/validator"
+	"github.com/hashicorp/terraform-plugin-log/tflog"
+	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/core"
+	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/validate"
+
+	"github.com/hashicorp/terraform-plugin-framework/datasource/schema"
+	"github.com/stackitcloud/stackit-sdk-go/core/config"
+	"github.com/stackitcloud/stackit-sdk-go/services/objectstorage"
+)
+
+// Ensure the implementation satisfies the expected interfaces.
+var (
+	_ datasource.DataSource = &credentialsGroupDataSource{}
+)
+
+// NewCredentialsGroupDataSource is a helper function to simplify the provider implementation.
+func NewCredentialsGroupDataSource() datasource.DataSource {
+	return &credentialsGroupDataSource{}
+}
+
+// credentialsGroupDataSource is the data source implementation.
+type credentialsGroupDataSource struct {
+	client *objectstorage.APIClient
+}
+
+// Metadata returns the data source type name.
+func (r *credentialsGroupDataSource) Metadata(_ context.Context, req datasource.MetadataRequest, resp *datasource.MetadataResponse) {
+	resp.TypeName = req.ProviderTypeName + "_objectstorage_credentials_group"
+}
+
+// Configure adds the provider configured client to the data source.
+func (r *credentialsGroupDataSource) Configure(ctx context.Context, req datasource.ConfigureRequest, resp *datasource.ConfigureResponse) {
+	// Prevent panic if the provider has not been configured.
+	if req.ProviderData == nil {
+		return
+	}
+
+	providerData, ok := req.ProviderData.(core.ProviderData)
+	if !ok {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error configuring API client", fmt.Sprintf("Expected configure type stackit.ProviderData, got %T", req.ProviderData))
+		return
+	}
+
+	var apiClient *objectstorage.APIClient
+	var err error
+	if providerData.ObjectStorageCustomEndpoint != "" {
+		apiClient, err = objectstorage.NewAPIClient(
+			config.WithCustomAuth(providerData.RoundTripper),
+			config.WithEndpoint(providerData.ObjectStorageCustomEndpoint),
+		)
+	} else {
+		apiClient, err = objectstorage.NewAPIClient(
+			config.WithCustomAuth(providerData.RoundTripper),
+			config.WithRegion(providerData.Region),
+		)
+	}
+
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error configuring API client", fmt.Sprintf("Configuring client: %v", err))
+		return
+	}
+
+	r.client = apiClient
+	tflog.Info(ctx, "ObjectStorage credentials group client configured")
+}
+
+// Schema defines the schema for the data source.
+func (r *credentialsGroupDataSource) Schema(_ context.Context, _ datasource.SchemaRequest, resp *datasource.SchemaResponse) {
+	descriptions := map[string]string{
+		"main":                 "ObjectStorage credentials group data source schema.",
+		"id":                   "Terraform's internal data source identifier. It is structured as \"`project_id`,`credentials_group_id`\".",
+		"credentials_group_id": "The credentials group ID",
+		"name":                 "The credentials group's display name.",
+		"project_id":           "Object Storage Project ID to which the credentials group is associated.",
+		"urn":                  "Credentials group uniform resource name (URN)",
+	}
+
+	resp.Schema = schema.Schema{
+		Description: descriptions["main"],
+		Attributes: map[string]schema.Attribute{
+			"id": schema.StringAttribute{
+				Description: descriptions["id"],
+				Computed:    true,
+			},
+			"credentials_group_id": schema.StringAttribute{
+				Description: descriptions["id"],
+				Optional:    true,
+				Computed:    true,
+			},
+			"project_id": schema.StringAttribute{
+				Description: descriptions["project_id"],
+				Required:    true,
+				Validators: []validator.String{
+					validate.UUID(),
+					validate.NoSeparator(),
+				},
+			},
+			"name": schema.StringAttribute{
+				Description: descriptions["name"],
+				Optional:    true,
+				Computed:    true,
+			},
+			"urn": schema.StringAttribute{
+				Computed:    true,
+				Description: descriptions["urn"],
+			},
+		},
+	}
+}
+
+// Read refreshes the Terraform state with the latest data.
+func (r *credentialsGroupDataSource) Read(ctx context.Context, req datasource.ReadRequest, resp *datasource.ReadResponse) { // nolint:gocritic // function signature required by Terraform
+	var model Model
+	diags := req.Config.Get(ctx, &model)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+	projectId := model.ProjectId.ValueString()
+	credentialsGroupId := model.CredentialsGroupId.ValueString()
+	ctx = tflog.SetField(ctx, "project_id", projectId)
+	ctx = tflog.SetField(ctx, "credentials_group_id", credentialsGroupId)
+
+	err := readCredentialsGroups(ctx, &model, r.client)
+	if err != nil {
+		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading credentialsGroup", fmt.Sprintf("getting credential group from list of credentials groups: %v", err))
+		return
+	}
+
+	// Set refreshed state
+	diags = resp.State.Set(ctx, model)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+	tflog.Info(ctx, "ObjectStorage credentials group read")
+}