pkg/asset/installconfig/aws: Extract regions from RHCOS metadata

pkg/asset/installconfig/aws/aws.go

@@ -2,6 +2,7 @@
 package aws
 
 import (
+	"context"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -12,6 +13,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/defaults"
 	"github.com/aws/aws-sdk-go/aws/request"
 	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/openshift/installer/pkg/rhcos"
 	"github.com/openshift/installer/pkg/types/aws"
 	"github.com/openshift/installer/pkg/types/aws/validation"
 	"github.com/openshift/installer/pkg/version"
@@ -25,7 +27,14 @@ import (
 func Platform() (*aws.Platform, error) {
 	longRegions := make([]string, 0, len(validation.Regions))
 	shortRegions := make([]string, 0, len(validation.Regions))
+	rhcosRegions, err := rhcos.AMIRegions(context.TODO())
+	if err != nil {
+		return nil, err
+	}
 	for id, location := range validation.Regions {
+		if _, ok := rhcosRegions[id]; !ok {
+			continue
+		}
 		longRegions = append(longRegions, fmt.Sprintf("%s (%s)", id, location))
 		shortRegions = append(shortRegions, id)
 	}

pkg/rhcos/ami.go

@@ -2,6 +2,8 @@ package rhcos
 
 import (
 	"context"
+	"sort"
+	"strings"
 
 	"github.com/pkg/errors"
 )
@@ -15,8 +17,31 @@ func AMI(ctx context.Context, region string) (string, error) {
 
 	ami, ok := meta.AMIs[region]
 	if !ok {
-		return "", errors.Errorf("no RHCOS AMIs found in %s", region)
+		regions := make([]string, 0, len(meta.AMIs))
+		for rgn := range meta.AMIs {
+			regions = append(regions, rgn)
+		}
+		sort.Strings(regions)
+
+		return "", errors.Errorf("no RHCOS AMIs found in %q (%s)", region, strings.Join(regions, ", "))
 	}
 
 	return ami.HVM, nil
 }
+
+// AMIRegions returns a set of AWS regions with HVM AMIs of the Red
+// Hat Enterprise Linux CoreOS release.
+func AMIRegions(ctx context.Context) (map[string]struct{}, error) {
+	meta, err := fetchRHCOSBuild(ctx)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to fetch RHCOS metadata")
+	}
+
+	exists := struct{}{}
+	regions := make(map[string]struct{}, len(meta.AMIs))
+	for region := range meta.AMIs {
+		regions[region] = exists
+	}
+
+	return regions, nil
+}

pkg/types/aws/validation/platform.go

@@ -1,10 +1,12 @@
 package validation
 
 import (
+	"context"
 	"sort"
 
 	"k8s.io/apimachinery/pkg/util/validation/field"
 
+	"github.com/openshift/installer/pkg/rhcos"
 	"github.com/openshift/installer/pkg/types/aws"
 )
 
@@ -13,29 +15,29 @@ var (
 	// the short name of the region. The value of the map is the long
 	// name of the region.
 	Regions = map[string]string{
-		//"ap-east-1":      "Hong Kong",
+		"ap-east-1":      "Hong Kong",
 		"ap-northeast-1": "Tokyo",
 		"ap-northeast-2": "Seoul",
-		//"ap-northeast-3": "Osaka-Local",
+		"ap-northeast-3": "Osaka-Local",
 		"ap-south-1":     "Mumbai",
 		"ap-southeast-1": "Singapore",
 		"ap-southeast-2": "Sydney",
 		"ca-central-1":   "Central",
-		//"cn-north-1":     "Beijing",
-		//"cn-northwest-1": "Ningxia",
-		"eu-central-1": "Frankfurt",
-		"eu-north-1":   "Stockholm",
-		"eu-west-1":    "Ireland",
-		"eu-west-2":    "London",
-		"eu-west-3":    "Paris",
-		//"me-south-1":   "Bahrain",
-		"sa-east-1": "São Paulo",
-		"us-east-1": "N. Virginia",
-		"us-east-2": "Ohio",
-		//"us-gov-east-1":  "AWS GovCloud (US-East)",
-		//"us-gov-west-1":  "AWS GovCloud (US-West)",
-		"us-west-1": "N. California",
-		"us-west-2": "Oregon",
+		"cn-north-1":     "Beijing",
+		"cn-northwest-1": "Ningxia",
+		"eu-central-1":   "Frankfurt",
+		"eu-north-1":     "Stockholm",
+		"eu-west-1":      "Ireland",
+		"eu-west-2":      "London",
+		"eu-west-3":      "Paris",
+		"me-south-1":     "Bahrain",
+		"sa-east-1":      "São Paulo",
+		"us-east-1":      "N. Virginia",
+		"us-east-2":      "Ohio",
+		"us-gov-east-1":  "AWS GovCloud (US-East)",
+		"us-gov-west-1":  "AWS GovCloud (US-West)",
+		"us-west-1":      "N. California",
+		"us-west-2":      "Oregon",
 	}
 
 	validRegionValues = func() []string {
@@ -55,6 +57,11 @@ func ValidatePlatform(p *aws.Platform, fldPath *field.Path) field.ErrorList {
 	allErrs := field.ErrorList{}
 	if _, ok := Regions[p.Region]; !ok {
 		allErrs = append(allErrs, field.NotSupported(fldPath.Child("region"), p.Region, validRegionValues))
+	} else if p.AMIID == "" {
+		_, err := rhcos.AMI(context.TODO(), p.Region)
+		if err != nil {
+			allErrs = append(allErrs, field.Invalid(fldPath.Child("region"), p.Region, err.Error()))
+		}
 	}
 	if p.DefaultMachinePlatform != nil {
 		allErrs = append(allErrs, ValidateMachinePool(p, p.DefaultMachinePlatform, fldPath.Child("defaultMachinePlatform"))...)

pkg/types/aws/validation/platform_test.go

@@ -13,29 +13,41 @@ func TestValidatePlatform(t *testing.T) {
 	cases := []struct {
 		name     string
 		platform *aws.Platform
-		valid    bool
+		expected string
 	}{
 		{
 			name: "minimal",
 			platform: &aws.Platform{
 				Region: "us-east-1",
 			},
-			valid: true,
 		},
 		{
 			name: "invalid region",
 			platform: &aws.Platform{
 				Region: "bad-region",
 			},
-			valid: false,
+			expected: "^test-path.region: Unsupported value: \"bad-region\": supported values: .*\"us-east-1\"",
+		},
+		{
+			name: "valid region without RHCOS",
+			platform: &aws.Platform{
+				Region: "us-gov-west-1",
+			},
+			expected: "^test-path.region: Invalid value: \"us-gov-west-1\": no RHCOS AMIs found in \"us-gov-west-1\" (.*us-east-1.*)$",
+		},
+		{
+			name: "valid region without RHCOS, but with an explicit AMI",
+			platform: &aws.Platform{
+				AMIID:  "ami-123",
+				Region: "us-gov-west-1",
+			},
 		},
 		{
 			name: "valid machine pool",
 			platform: &aws.Platform{
 				Region:                 "us-east-1",
 				DefaultMachinePlatform: &aws.MachinePool{},
 			},
-			valid: true,
 		},
 		{
 			name: "invalid machine pool",
@@ -47,16 +59,16 @@ func TestValidatePlatform(t *testing.T) {
 					},
 				},
 			},
-			valid: false,
+			expected: "^test-path.defaultMachinePlatform.iops: Invalid value: -10: Storage IOPS must be positive$",
 		},
 	}
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {
 			err := ValidatePlatform(tc.platform, field.NewPath("test-path")).ToAggregate()
-			if tc.valid {
+			if tc.expected == "" {
 				assert.NoError(t, err)
 			} else {
-				assert.Error(t, err)
+				assert.Regexp(t, tc.expected, err)
 			}
 		})
 	}

pkg/types/validation/installconfig_test.go

@@ -407,7 +407,7 @@ func TestValidateInstallConfig(t *testing.T) {
 				}
 				return c
 			}(),
-			expectedError: `^platform\.aws\.region: Unsupported value: "": supported values: "ap-northeast-1", "ap-northeast-2", "ap-south-1", "ap-southeast-1", "ap-southeast-2", "ca-central-1", "eu-central-1", "eu-north-1", "eu-west-1", "eu-west-2", "eu-west-3", "sa-east-1", "us-east-1", "us-east-2", "us-west-1", "us-west-2"$`,
+			expectedError: `^platform\.aws\.region: Unsupported value: "": supported values: .*"us-east-1"`,
 		},
 		{
 			name: "valid libvirt platform",