terraform-provider: cleanup and improve docs (#2685)

Co-authored-by: Moritz Sanft <58110325+msanft@users.noreply.github.com>

terraform-provider-constellation/BUILD.bazel

@@ -31,6 +31,9 @@ go_library(
     srcs = ["main.go"],
     importpath = "github.com/edgelesssys/constellation/v2/terraform-provider-constellation",
     visibility = ["//visibility:private"],
+    x_defs = {
+        "version": "{STABLE_STAMP_VERSION}",
+    },
     deps = [
         "//terraform-provider-constellation/internal/provider",
         "@com_github_hashicorp_terraform_plugin_framework//providerserver",

terraform-provider-constellation/docs/data-sources/attestation.md

@@ -32,10 +32,10 @@ data "constellation_attestation" "test" {
   * `gcp-sev-es`
 - `csp` (String) CSP (Cloud Service Provider) to use. (e.g. `azure`)
 See the [full list of CSPs](https://docs.edgeless.systems/constellation/overview/clouds) that Constellation supports.
-- `image_version` (String) The image version to use
 
 ### Optional
 
+- `image_version` (String) The image version to use. If not set, the provider version value is used.
 - `maa_url` (String) For Azure only, the URL of the Microsoft Azure Attestation service
 
 ### Read-Only

terraform-provider-constellation/docs/data-sources/image.md

@@ -3,12 +3,12 @@
 page_title: "constellation_image Data Source - constellation"
 subcategory: ""
 description: |-
-  Data source to retrieve the Constellation OS image reference for a given CSP and Attestation Variant.
+  Data source to resolve the CSP-specific OS image reference for a given version and attestation variant.
 ---
 
 # constellation_image (Data Source)
 
-Data source to retrieve the Constellation OS image reference for a given CSP and Attestation Variant.
+Data source to resolve the CSP-specific OS image reference for a given version and attestation variant.
 
 ## Example Usage
 
@@ -33,10 +33,10 @@ data "constellation_image" "example" {
   * `gcp-sev-es`
 - `csp` (String) CSP (Cloud Service Provider) to use. (e.g. `azure`)
 See the [full list of CSPs](https://docs.edgeless.systems/constellation/overview/clouds) that Constellation supports.
-- `image_version` (String) Version of the Constellation OS image to use. (e.g. `v2.13.0`)
 
 ### Optional
 
+- `image_version` (String) Version of the Constellation OS image to use. (e.g. `v2.13.0`). If not set, the provider version value is used.
 - `marketplace_image` (Boolean) Whether a marketplace image should be used. Currently only supported for Azure.
 - `region` (String) Region to retrieve the image for. Only required for AWS.
 The Constellation OS image must be [replicated to the region](https://docs.edgeless.systems/constellation/workflows/config),and the region must [support AMD SEV-SNP](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/snp-requirements.html), if it is used for Attestation.

terraform-provider-constellation/docs/index.md

@@ -4,12 +4,19 @@ page_title: "constellation Provider"
 subcategory: ""
 description: |-
   The Constellation provider manages Constellation clusters.
+  Given user-defined infrastructure in Terraform, the provider with its main 'constellation_cluster' resource manages the entire lifecycle of a cluster.
+  The provider allows easy usage of custom infrastructure setups and GitOps workflows.
+  It is released as part of Constellation releases, such that each provider version is compatible with the corresponding Constellation version.
 ---
 
 # constellation Provider
 
 The Constellation provider manages Constellation clusters.
 
+Given user-defined infrastructure in Terraform, the provider with its main 'constellation_cluster' resource manages the entire lifecycle of a cluster.
+The provider allows easy usage of custom infrastructure setups and GitOps workflows.
+It is released as part of Constellation releases, such that each provider version is compatible with the corresponding Constellation version.
+
 ## Example Usage
 
 ```terraform

terraform-provider-constellation/docs/resources/cluster.md

@@ -42,7 +42,7 @@ resource "constellation_cluster" "aws_example" {
 
 ### Required
 
-- `attestation` (Attributes) Attestation comprises the measurements and SEV-SNP specific parameters. (see [below for nested schema](#nestedatt--attestation))
+- `attestation` (Attributes) Attestation comprises the measurements and SEV-SNP specific parameters. The output of the [constellation_attestation](../data-sources/attestation.md) data source provides sensible defaults. (see [below for nested schema](#nestedatt--attestation))
 - `csp` (String) The Cloud Service Provider (CSP) the cluster should run on.
 - `image_reference` (String) Constellation OS image reference to use in the CSP specific reference format. Use the [`constellation_image`](../data-sources/image.md) data source to find the correct image reference for your CSP.
 - `image_version` (String) Constellation OS image version to use in the CSP specific reference format. Use the [`constellation_image`](../data-sources/image.md) data source to find the correct image version for your CSP.

terraform-provider-constellation/internal/data/providerdata.go

@@ -8,4 +8,6 @@ package data
 
 // ProviderData is the data that get's passed down from the provider
 // configuration to the resources and data sources.
-type ProviderData struct{}
+type ProviderData struct {
+	Version string
+}

terraform-provider-constellation/internal/provider/BUILD.bazel

@@ -78,12 +78,15 @@ go_test(
         "requires-network",
     ],
     # keep
-    x_defs = {"runsUnder": "bazel"},
+    x_defs = {
+        "runsUnder": "bazel",
+    },
     deps = [
         "//internal/attestation/idkeydigest",
         "//internal/attestation/measurements",
         "//internal/attestation/variant",
         "//internal/config",
+        "//internal/constants",
         "@com_github_hashicorp_terraform_plugin_framework//providerserver",
         "@com_github_hashicorp_terraform_plugin_go//tfprotov6",
         "@com_github_hashicorp_terraform_plugin_testing//helper/resource",

terraform-provider-constellation/internal/provider/attestation_data_source.go

@@ -17,6 +17,7 @@ import (
 	"github.com/edgelesssys/constellation/v2/internal/attestation/variant"
 	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
 	"github.com/edgelesssys/constellation/v2/internal/sigstore"
+	"github.com/edgelesssys/constellation/v2/terraform-provider-constellation/internal/data"
 	"github.com/hashicorp/terraform-plugin-framework/datasource"
 	"github.com/hashicorp/terraform-plugin-framework/datasource/schema"
 	"github.com/hashicorp/terraform-plugin-framework/path"
@@ -37,6 +38,7 @@ type AttestationDataSource struct {
 	client  *http.Client
 	fetcher attestationconfigapi.Fetcher
 	rekor   *sigstore.Rekor
+	version string
 }
 
 // AttestationDataSourceModel describes the data source data model.
@@ -49,7 +51,21 @@ type AttestationDataSourceModel struct {
 }
 
 // Configure configures the data source.
-func (d *AttestationDataSource) Configure(_ context.Context, _ datasource.ConfigureRequest, resp *datasource.ConfigureResponse) {
+func (d *AttestationDataSource) Configure(_ context.Context, req datasource.ConfigureRequest, resp *datasource.ConfigureResponse) {
+	// Prevent panic if the provider has not been configured. is necessary!
+	if req.ProviderData == nil {
+		return
+	}
+	providerData, ok := req.ProviderData.(data.ProviderData)
+	if !ok {
+		resp.Diagnostics.AddError(
+			"Unexpected Data Source Configure Type",
+			fmt.Sprintf("Expected data.ProviderData, got: %T. Please report this issue to the provider developers.", req.ProviderData),
+		)
+		return
+	}
+	d.version = providerData.Version
+
 	d.client = http.DefaultClient
 	d.fetcher = attestationconfigapi.NewFetcher()
 	rekor, err := sigstore.NewRekor()
@@ -70,13 +86,12 @@ func (d *AttestationDataSource) Schema(_ context.Context, _ datasource.SchemaReq
 	resp.Schema = schema.Schema{
 		// This description is used by the documentation generator and the language server.
 		MarkdownDescription: "The data source to fetch measurements from a configured cloud provider and image.",
-
 		Attributes: map[string]schema.Attribute{
 			"csp":                 newCSPAttribute(),
 			"attestation_variant": newAttestationVariantAttribute(attributeInput),
 			"image_version": schema.StringAttribute{
-				MarkdownDescription: "The image version to use",
-				Required:            true,
+				MarkdownDescription: "The image version to use. If not set, the provider version value is used.",
+				Optional:            true,
 			},
 			"maa_url": schema.StringAttribute{
 				MarkdownDescription: "For Azure only, the URL of the Microsoft Azure Attestation service",
@@ -87,6 +102,28 @@ func (d *AttestationDataSource) Schema(_ context.Context, _ datasource.SchemaReq
 	}
 }
 
+// ValidateConfig validates the configuration for the image data source.
+func (d *AttestationDataSource) ValidateConfig(ctx context.Context, req datasource.ValidateConfigRequest, resp *datasource.ValidateConfigResponse) {
+	var data AttestationDataSourceModel
+
+	resp.Diagnostics.Append(req.Config.Get(ctx, &data)...)
+
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	if !data.AttestationVariant.Equal(types.StringValue("azure-sev-snp")) && !data.MaaURL.IsNull() {
+		resp.Diagnostics.AddAttributeWarning(
+			path.Root("maa_url"),
+			"MAA URL should only be set for Azure SEV-SNP", "Only when attestation_variant is set to 'azure-sev-snp', 'maa_url' should be specified.",
+		)
+		return
+	}
+	if data.AttestationVariant.Equal(types.StringValue("azure-sev-snp")) && data.MaaURL.IsNull() {
+		tflog.Info(ctx, "MAA URL not set, MAA fallback will be unavaiable")
+	}
+}
+
 // Read reads from the data source.
 func (d *AttestationDataSource) Read(ctx context.Context, req datasource.ReadRequest, resp *datasource.ReadResponse) {
 	var data AttestationDataSourceModel
@@ -130,7 +167,13 @@ func (d *AttestationDataSource) Read(ctx context.Context, req datasource.ReadReq
 		resp.Diagnostics.AddError("Converting SNP attestation", err.Error())
 	}
 	verifyFetcher := measurements.NewVerifyFetcher(sigstore.NewCosignVerifier, d.rekor, d.client)
-	fetchedMeasurements, err := verifyFetcher.FetchAndVerifyMeasurements(ctx, data.ImageVersion.ValueString(),
+
+	imageVersion := data.ImageVersion.ValueString()
+	if imageVersion == "" {
+		tflog.Info(ctx, fmt.Sprintf("No image version specified, using provider version %s", d.version))
+		imageVersion = d.version // Use provider version as default.
+	}
+	fetchedMeasurements, err := verifyFetcher.FetchAndVerifyMeasurements(ctx, imageVersion,
 		csp, attestationVariant, false)
 	if err != nil {
 		var rekErr *measurements.RekorError

terraform-provider-constellation/internal/provider/attestation_data_source_test.go

@@ -17,8 +17,8 @@ func TestAccAttestationSource(t *testing.T) {
 	bazelPreCheck := func() { bazelSetTerraformBinaryPath(t) }
 
 	testCases := map[string]resource.TestCase{
-		"aws sev-snp succcess": {
-			ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
+		"aws sev-snp succcess without explicit image_version": {
+			ProtoV6ProviderFactories: testAccProtoV6ProviderFactoriesWithVersion("v2.13.0"), // do this to test if a valid default version is set
 			PreCheck:                 bazelPreCheck,
 			Steps: []resource.TestStep{
 				{
@@ -26,7 +26,6 @@ func TestAccAttestationSource(t *testing.T) {
 					data "constellation_attestation" "test" {
 						csp = "aws"
 						attestation_variant = "aws-sev-snp"
-						image_version = "v2.13.0"
 					}
 					`,
 					Check: resource.ComposeAggregateTestCheckFunc(
@@ -54,6 +53,7 @@ func TestAccAttestationSource(t *testing.T) {
 						csp = "azure"
 						attestation_variant = "azure-sev-snp"
 						image_version = "v2.13.0"
+						maa_url = "https://www.example.com"
 					}
 					`,
 					Check: resource.ComposeAggregateTestCheckFunc(

terraform-provider-constellation/internal/provider/image_data_source.go

@@ -14,10 +14,12 @@ import (
 	"github.com/edgelesssys/constellation/v2/internal/attestation/variant"
 	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
 	"github.com/edgelesssys/constellation/v2/internal/imagefetcher"
+	"github.com/edgelesssys/constellation/v2/terraform-provider-constellation/internal/data"
 	"github.com/hashicorp/terraform-plugin-framework/datasource"
 	"github.com/hashicorp/terraform-plugin-framework/datasource/schema"
 	"github.com/hashicorp/terraform-plugin-framework/path"
 	"github.com/hashicorp/terraform-plugin-framework/types"
+	"github.com/hashicorp/terraform-plugin-log/tflog"
 )
 
 var (
@@ -38,6 +40,7 @@ func NewImageDataSource() datasource.DataSource {
 // It is used to retrieve the Constellation OS image reference for a given CSP and Attestation Variant.
 type ImageDataSource struct {
 	imageFetcher imageFetcher
+	version      string
 }
 
 // imageFetcher gets an image reference from the versionsapi.
@@ -66,14 +69,14 @@ func (d *ImageDataSource) Metadata(_ context.Context, req datasource.MetadataReq
 // Schema returns the schema for the image data source.
 func (d *ImageDataSource) Schema(_ context.Context, _ datasource.SchemaRequest, resp *datasource.SchemaResponse) {
 	resp.Schema = schema.Schema{
-		Description:         "Data source to retrieve the Constellation OS image reference for a given CSP and Attestation Variant.",
-		MarkdownDescription: "Data source to retrieve the Constellation OS image reference for a given CSP and Attestation Variant.",
+		Description:         "The data source to resolve the CSP-specific OS image reference for a given version and attestation variant.",
+		MarkdownDescription: "Data source to resolve the CSP-specific OS image reference for a given version and attestation variant.",
 		Attributes: map[string]schema.Attribute{
 			"attestation_variant": newAttestationVariantAttribute(attributeInput),
 			"image_version": schema.StringAttribute{
-				Description:         "Version of the Constellation OS image to use. (e.g. `v2.13.0`)",
-				MarkdownDescription: "Version of the Constellation OS image to use. (e.g. `v2.13.0`)",
-				Required:            true, // TODO(msanft): Make this optional to support "lockstep" mode.
+				Description:         "Version of the Constellation OS image to use. (e.g. `v2.13.0`). If not set, the provider version is used.",
+				MarkdownDescription: "Version of the Constellation OS image to use. (e.g. `v2.13.0`). If not set, the provider version value is used.",
+				Optional:            true,
 			},
 			"csp": newCSPAttribute(),
 			"marketplace_image": schema.BoolAttribute{
@@ -97,13 +100,43 @@ func (d *ImageDataSource) Schema(_ context.Context, _ datasource.SchemaRequest,
 	}
 }
 
-// TODO(msanft): Possibly implement more complex validation for inter-dependencies between attributes.
-// E.g., region should be required if, and only if, AWS is used.
+// ValidateConfig validates the configuration for the image data source.
+func (d *ImageDataSource) ValidateConfig(ctx context.Context, req datasource.ValidateConfigRequest, resp *datasource.ValidateConfigResponse) {
+	var data ImageDataSourceModel
+
+	resp.Diagnostics.Append(req.Config.Get(ctx, &data)...)
+
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	if data.CSP.Equal(types.StringValue("aws")) && data.Region.IsNull() {
+		resp.Diagnostics.AddAttributeError(
+			path.Root("region"),
+			"Region must be set for AWS", "When csp is set to 'aws', 'region' must be specified.",
+		)
+		return
+	}
+}
 
 // Configure configures the data source.
-func (d *ImageDataSource) Configure(_ context.Context, _ datasource.ConfigureRequest, _ *datasource.ConfigureResponse) {
-	// Create the image-fetcher client.
+func (d *ImageDataSource) Configure(_ context.Context, req datasource.ConfigureRequest, resp *datasource.ConfigureResponse) {
 	d.imageFetcher = imagefetcher.New()
+
+	// Prevent panic if the provider has not been configured. is necessary!
+	if req.ProviderData == nil {
+		return
+	}
+	providerData, ok := req.ProviderData.(data.ProviderData)
+	if !ok {
+		resp.Diagnostics.AddError(
+			"Unexpected Data Source Configure Type",
+			fmt.Sprintf("Expected data.ProviderData, got: %T. Please report this issue to the provider developers.", req.ProviderData),
+		)
+		return
+	}
+
+	d.version = providerData.Version
 }
 
 // Read reads from the data source.
@@ -111,7 +144,6 @@ func (d *ImageDataSource) Read(ctx context.Context, req datasource.ReadRequest,
 	// Retrieve the configuration values for this data source instance.
 	var data ImageDataSourceModel
 	resp.Diagnostics.Append(req.Config.Get(ctx, &data)...)
-
 	// Check configuration for errors.
 	csp := cloudprovider.FromString(data.CSP.ValueString())
 	if csp == cloudprovider.Unknown {
@@ -135,9 +167,15 @@ func (d *ImageDataSource) Read(ctx context.Context, req datasource.ReadRequest,
 		return
 	}
 
+	imageVersion := data.ImageVersion.ValueString()
+	if imageVersion == "" {
+		tflog.Info(ctx, fmt.Sprintf("No image version specified, using provider version %s", d.version))
+		imageVersion = d.version // Use provider version as default.
+	}
+
 	// Retrieve Image Reference
 	imageRef, err := d.imageFetcher.FetchReference(ctx, csp, attestationVariant,
-		data.ImageVersion.ValueString(), data.Region.ValueString(), data.MarketplaceImage.ValueBool())
+		imageVersion, data.Region.ValueString(), data.MarketplaceImage.ValueBool())
 	if err != nil {
 		resp.Diagnostics.AddError(
 			"Error fetching Image Reference",

terraform-provider-constellation/internal/provider/image_data_source_test.go

@@ -18,6 +18,22 @@ func TestAccImageDataSource(t *testing.T) {
 	bazelPreCheck := func() { bazelSetTerraformBinaryPath(t) }
 
 	testCases := map[string]resource.TestCase{
+		"no image_version succeeds": {
+			ProtoV6ProviderFactories: testAccProtoV6ProviderFactoriesWithVersion("v2.13.0"),
+			PreCheck:                 bazelPreCheck,
+			Steps: []resource.TestStep{
+				{
+					Config: testingConfig + `
+					data "constellation_image" "test" {
+						attestation_variant = "aws-sev-snp"
+						csp                 = "aws"
+						region              = "eu-west-1"
+					}
+				`,
+					Check: resource.TestCheckResourceAttrSet("data.constellation_image.test", "reference"),
+				},
+			},
+		},
 		"aws succcess": {
 			ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
 			PreCheck:                 bazelPreCheck,
@@ -37,6 +53,23 @@ func TestAccImageDataSource(t *testing.T) {
 				},
 			},
 		},
+		"aws without region fails": {
+			ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
+			PreCheck:                 bazelPreCheck,
+			Steps: []resource.TestStep{
+				// Read testing
+				{
+					Config: testingConfig + `
+					data "constellation_image" "test" {
+						image_version       = "v2.13.0"
+						attestation_variant = "aws-sev-snp"
+						csp                 = "aws"
+					}
+				`,
+					ExpectError: regexp.MustCompile(".*Region must be set for AWS.*"),
+				},
+			},
+		},
 		"azure success": {
 			ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
 			PreCheck:                 bazelPreCheck,

terraform-provider-constellation/internal/provider/provider.go

@@ -27,9 +27,7 @@ type ConstellationProviderModel struct{}
 
 // ConstellationProvider is the provider implementation.
 type ConstellationProvider struct {
-	// version is set to the provider version on release, "dev" when the
-	// provider is built and ran locally, and "test" when running acceptance
-	// testing.
+	// version is set to the provider version on release, and the pseudo version on local builds. The pseudo version is not a valid default for the image_version attribute.
 	version string
 }
 
@@ -51,8 +49,12 @@ func (p *ConstellationProvider) Metadata(_ context.Context, _ provider.MetadataR
 // Schema defines the HCL schema of the provider, i.e. what attributes it has and what they are used for.
 func (p *ConstellationProvider) Schema(_ context.Context, _ provider.SchemaRequest, resp *provider.SchemaResponse) {
 	resp.Schema = schema.Schema{
-		Description:         "The Constellation provider manages Constellation clusters.",
-		MarkdownDescription: `The Constellation provider manages Constellation clusters.`, // TODO(msanft): Provide a more sophisticated description.
+		Description: "The Constellation provider manages Constellation clusters.",
+		MarkdownDescription: `The Constellation provider manages Constellation clusters.
+
+Given user-defined infrastructure in Terraform, the provider with its main 'constellation_cluster' resource manages the entire lifecycle of a cluster.
+The provider allows easy usage of custom infrastructure setups and GitOps workflows.
+It is released as part of Constellation releases, such that each provider version is compatible with the corresponding Constellation version.`,
 	}
 }
 
@@ -67,8 +69,9 @@ func (p *ConstellationProvider) Configure(ctx context.Context, req provider.Conf
 		return
 	}
 
-	// TODO(msanft): Initialize persistent clients here.
-	config := datastruct.ProviderData{}
+	config := datastruct.ProviderData{
+		Version: p.version,
+	}
 
 	// Make the clients available during data source and resource "Configure" methods.
 	resp.DataSourceData = config

terraform-provider-constellation/internal/provider/provider_test.go

@@ -12,6 +12,7 @@ import (
 	"testing"
 
 	"github.com/bazelbuild/rules_go/go/runfiles"
+	"github.com/edgelesssys/constellation/v2/internal/constants"
 	"github.com/hashicorp/terraform-plugin-framework/providerserver"
 	"github.com/hashicorp/terraform-plugin-go/tfprotov6"
 )
@@ -26,9 +27,17 @@ const (
 // testAccProtoV6ProviderFactories are used to instantiate a provider during
 // acceptance testing. The factory function will be invoked for every Terraform
 // CLI command executed to create a provider server to which the CLI can
+// reattach. It sets a pseudo version for the provider version.
+var testAccProtoV6ProviderFactories = testAccProtoV6ProviderFactoriesWithVersion(constants.BinaryVersion().String())
+
+// testAccProtoV6ProviderFactoriesWithVersion are used to instantiate a provider during
+// acceptance testing. The factory function will be invoked for every Terraform
+// CLI command executed to create a provider server to which the CLI can
 // reattach.
-var testAccProtoV6ProviderFactories = map[string]func() (tfprotov6.ProviderServer, error){
-	"constellation": providerserver.NewProtocol6WithError(New("test")()),
+var testAccProtoV6ProviderFactoriesWithVersion = func(version string) map[string]func() (tfprotov6.ProviderServer, error) {
+	return map[string]func() (tfprotov6.ProviderServer, error){
+		"constellation": providerserver.NewProtocol6WithError(New(version)()),
+	}
 }
 
 // bazelSetTerraformBinaryPath sets the path to the Terraform binary for

terraform-provider-constellation/internal/provider/shared_attributes.go

@@ -73,11 +73,15 @@ func newMeasurementsAttribute(t attributeType) schema.Attribute {
 
 func newAttestationConfigAttribute(t attributeType) schema.Attribute {
 	isInput := bool(t)
+	var additionalDescription string
+	if isInput {
+		additionalDescription = " The output of the [constellation_attestation](../data-sources/attestation.md) data source provides sensible defaults.  "
+	}
 	return schema.SingleNestedAttribute{
 		Computed:            !isInput,
 		Required:            isInput,
-		MarkdownDescription: "Attestation comprises the measurements and SEV-SNP specific parameters.",
-		Description:         "The values provide sensible defaults. See the docs for advanced usage.", // TODO(elchead): AB#3568
+		MarkdownDescription: "Attestation comprises the measurements and SEV-SNP specific parameters." + additionalDescription,
+		Description:         "Attestation comprises the measurements and SEV-SNP specific parameters." + additionalDescription,
 		Attributes: map[string]schema.Attribute{
 			"variant": newAttestationVariantAttribute(t), // duplicated for convenience in cluster resource
 			"bootloader_version": schema.Int64Attribute{

terraform-provider-constellation/main.go

@@ -15,7 +15,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-framework/providerserver"
 )
 
-// TODO(msanft): Set this accordingly in the release CI.
+// version is the version of Constellation to use. Left as a separate variable to allow override during build.
 var version = "dev"
 
 func main() {