Support configuring provider via environment variables (#1)

We should be able to set `base_url` and `default_namespace` via
environment variables. It will add more flexibility for the provider
users, as well as allow us to make the acceptance tests more dynamic.

In addition, let's add `docker-compose` to support testing with local
instance.

.github/workflows/test.yml

@@ -5,16 +5,22 @@ name: Tests
 # Optionally, you can turn it on using a schedule for regular testing.
 on:
   pull_request:
+    branches: [ "main" ]
     paths-ignore:
       - 'README.md'
   push:
+    branches: [ "main" ]
     paths-ignore:
       - 'README.md'
 
 # Testing only needs permissions to read the repository contents.
 permissions:
   contents: read
 
+concurrency:
+  group: Tests-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   # Ensure project builds before running testing matrix
   build:
@@ -50,6 +56,11 @@ jobs:
     name: Acceptance Tests
     needs: build
     runs-on: ubuntu-latest
+    services:
+      backstage:
+        image: roadiehq/community-backstage-image
+        ports:
+          - 7000
     timeout-minutes: 15
     strategy:
       fail-fast: false
@@ -72,5 +83,12 @@ jobs:
       - run: go mod download
       - env:
           TF_ACC: "1"
+          ACCTEST_SKIP_RESOURCE_TEST: "1"
+          BACKSTAGE_BASE_URL: "https://demo.backstage.io"
         run: go test -v -cover ./backstage
         timeout-minutes: 10
+      - env:
+          TF_ACC: "1"
+          BACKSTAGE_BASE_URL: "http://localhost:${{ job.services.backstage.ports[7000] }}"
+        run: go test -v -cover ./backstage/resource_location_test.go
+        timeout-minutes: 10

GNUmakefile

@@ -1,6 +1,12 @@
 default: testacc
 
+ifdef BACKSTAGE_BASE_URL
+BACKSTAGE_BASE_URL := $(BACKSTAGE_BASE_URL)
+else
+BACKSTAGE_BASE_URL := http://demo.backstage.io
+endif
+
 # Run acceptance tests
 .PHONY: testacc
 testacc:
-	TF_ACC=1 go test ./... -v $(TESTARGS) -timeout 120m -cover
+	TF_ACC=1 BACKSTAGE_BASE_URL=${BACKSTAGE_BASE_URL} go test ./... -v $(TESTARGS) -timeout 120m -cover

README.md

@@ -23,6 +23,7 @@ most of the official documentation on developing this provider is also applicabl
 - [Terraform](https://www.terraform.io/downloads)
 - [Go](https://go.dev/doc/install) (1.19)
 - [GNU make](https://www.gnu.org/software/make/)
+- [Docker](https://docs.docker.com/get-docker/) (optional)
 
 ### Building
 
@@ -40,7 +41,25 @@ In order to test the provider, run the following command:
 make testacc
 ```
 
-This will run acceptance tests against the provider, actually spawning terraform and the provider.
+This will run acceptance tests against the provider , actually spawning terraform and the provider, using `https://demo.backstage.io` as the Backstage instance. The instance can
+be changed by setting the `BACKSTAGE_BASE_URL` environment variable, e.g.:
+
+```bash
+BACKSTAGE_BASE_URL=https://localhost:3000 make testacc
+```
+
+The project contains a [`docker-compose.yml`](./docker-compose.yml) file that can be used to spin up a local instance of Backstage, which can be used for testing. To do so, run:
+
+```bash
+docker-compose up -d
+```
+
+Some tests (i.e. resource tests) do not work with the public [demo instance](https://demo.backstage.io) of Backstage, as they modify the data. To skip those tests while using
+the demo instance, run:
+
+```bash
+ACCTEST_SKIP_RESOURCE_TEST=1 make testacc
+```
 
 ### Generating documentation
 
@@ -62,4 +81,4 @@ Thank you for your interest in improving the project.
 
 ## License
 
-This provider is distributed under the Mozilla Public License v2.0 license found in the [LICENSE](./LICENSE) file.
+This provider is distributed under the Mozilla Public License v2.0 license found in the [`LICENSE`](./LICENSE) file.

backstage/provider.go

@@ -3,6 +3,7 @@ package backstage
 import (
 	"context"
 	"fmt"
+	"os"
 	"regexp"
 
 	"github.com/hashicorp/terraform-plugin-framework-validators/stringvalidator"
@@ -31,8 +32,12 @@ type backstageProviderModel struct {
 }
 
 const (
-	descriptionProviderBaseURL          = "Base URL of the Backstage instance, e.g. https://demo.backstage.io."
-	descriptionProviderDefaultNamespace = "Name of default namespace for entities (`default`, if not set)."
+	envBaseURL                 = "BACKSTAGE_BASE_URL"
+	envDefaultNamespace        = "BACKSTAGE_DEFAULT_NAMESPACE"
+	descriptionProviderBaseURL = "Base URL of the Backstage instance, e.g. https://demo.backstage.io. May also be provided via `" + envBaseURL +
+		"` environment variable."
+	descriptionProviderDefaultNamespace = "Name of default namespace for entities (`default`, if not set). May also be provided via `" + envDefaultNamespace +
+		"` environment variable."
 )
 
 // Metadata returns the provider type name.
@@ -51,13 +56,13 @@ func (p *backstageProvider) Schema(_ context.Context, _ provider.SchemaRequest,
 			"Interested in the provider's latest features, or want to make sure you're up to date? Check out the " +
 			"[releases](https://github.com/tdabasinskas/terraform-provider-backstage/releases) for version information and release notes.",
 		Attributes: map[string]schema.Attribute{
-			"base_url": schema.StringAttribute{Required: true, Description: descriptionProviderBaseURL, Validators: []validator.String{
+			"base_url": schema.StringAttribute{Optional: true, MarkdownDescription: descriptionProviderBaseURL, Validators: []validator.String{
 				stringvalidator.RegexMatches(
 					regexp.MustCompile(`https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)`),
 					"must be a valid URL",
 				),
 			}},
-			"default_namespace": schema.StringAttribute{Optional: true, Description: descriptionProviderDefaultNamespace, Validators: []validator.String{
+			"default_namespace": schema.StringAttribute{Optional: true, MarkdownDescription: descriptionProviderDefaultNamespace, Validators: []validator.String{
 				stringvalidator.LengthBetween(1, 63),
 				stringvalidator.RegexMatches(
 					regexp.MustCompile(patternEntityName),
@@ -79,23 +84,40 @@ func (p *backstageProvider) Configure(ctx context.Context, req provider.Configur
 		return
 	}
 
-	baseURL := config.BaseURL.ValueString()
-	if config.BaseURL.IsUnknown() || config.BaseURL.IsNull() {
-		resp.Diagnostics.AddAttributeError(path.Root("base_url"),
-			"Unknown Base URL of Backstage instance", "Either target apply the source of the value first, or set the value statically in the configuration")
+	if config.BaseURL.IsUnknown() {
+		resp.Diagnostics.AddAttributeError(path.Root("base_url"), "Unknown Base URL of Backstage instance", fmt.Sprintf(
+			"Either target apply the source of the value first, set the value statically in the configuration, or use the %s environment variable.", envBaseURL))
 	}
 
 	if config.DefaultNamespace.IsUnknown() {
-		resp.Diagnostics.AddAttributeError(path.Root("default_namespace"),
-			"Unknown default entities namespace of Backstage instance",
-			"Either target apply the source of the value first, or set the value statically in the configuration")
+		resp.Diagnostics.AddAttributeError(path.Root("default_namespace"), "Unknown default entities namespace of Backstage instance", fmt.Sprintf(
+			"Either target apply the source of the value first, set the value statically in the configuration, or use the %s environment variable.", envDefaultNamespace))
 	}
 
-	defaultNamespace := config.DefaultNamespace.ValueString()
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	baseURL := os.Getenv(envBaseURL)
+	if !config.BaseURL.IsNull() {
+		baseURL = config.BaseURL.ValueString()
+	}
+
+	defaultNamespace := os.Getenv(envDefaultNamespace)
+	if !config.DefaultNamespace.IsNull() {
+		defaultNamespace = config.DefaultNamespace.ValueString()
+	}
 	if defaultNamespace == "" {
 		defaultNamespace = backstage.DefaultNamespaceName
 	}
 
+	if baseURL == "" {
+		resp.Diagnostics.AddAttributeError(path.Root("base_url"), "Missing Base URL of Backstage instance", fmt.Sprintf(
+			"The provider cannot create the Backstage API client as there is a missing or empty value for the Backstage Base URL. Set the host value in the "+
+				"configuration or use the %s environment variable. If either is already set, ensure the value is not empty.", envBaseURL))
+
+	}
+
 	if resp.Diagnostics.HasError() {
 		return
 	}

backstage/provider_test.go

@@ -7,7 +7,6 @@ import (
 
 const testAccProviderConfig = `
 provider "backstage" {
-	base_url = "https://demo.backstage.io"
 }
 `
 

backstage/resource_location.go

@@ -0,0 +1 @@
+package backstage

backstage/resource_location_test.go

@@ -0,0 +1,12 @@
+package backstage
+
+import (
+	"os"
+	"testing"
+)
+
+func TestAccResourceLocation(t *testing.T) {
+	if os.Getenv("ACCTEST_SKIP_RESOURCE_TEST") != "" {
+		t.Skip("Skipping as ACCTEST_SKIP_RESOURCE_LOCATION is set")
+	}
+}

docker-compose.yml

@@ -0,0 +1,8 @@
+version: '3.8'
+services:
+  backstage:
+    image: roadiehq/community-backstage-image:latest
+    ports:
+      - '3000:7000'
+    environment:
+      GITHUB_TOKEN: ${GITHUB_TOKEN}

docs/index.md

@@ -34,10 +34,7 @@ provider "backstage" {
 <!-- schema generated by tfplugindocs -->
 ## Schema
 
-### Required
-
-- `base_url` (String) Base URL of the Backstage instance, e.g. https://demo.backstage.io.
-
 ### Optional
 
-- `default_namespace` (String) Name of default namespace for entities (`default`, if not set).
+- `base_url` (String) Base URL of the Backstage instance, e.g. https://demo.backstage.io. May also be provided via `BACKSTAGE_BASE_URL` environment variable.
+- `default_namespace` (String) Name of default namespace for entities (`default`, if not set). May also be provided via `BACKSTAGE_DEFAULT_NAMESPACE` environment variable.