Allow to set the 'InfraID' with an environment variable.

pkg/asset/installconfig/clusterid.go

@@ -2,10 +2,13 @@ package installconfig
 
 import (
 	"fmt"
+	"os"
 	"regexp"
 	"strings"
 
 	"github.com/pborman/uuid"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 	utilrand "k8s.io/apimachinery/pkg/util/rand"
 
 	"github.com/openshift/installer/pkg/asset"
@@ -44,7 +47,11 @@ func (a *ClusterID) Generate(dep asset.Parents) error {
 	maxLen := 27
 
 	// add random chars to the end to randomize
-	a.InfraID = generateInfraID(ica.Config.ObjectMeta.Name, maxLen)
+	infraID, err := generateInfraID(ica.Config.ObjectMeta.Name, maxLen)
+	if err != nil {
+		return err
+	}
+	a.InfraID = infraID
 	a.UUID = uuid.New()
 	return nil
 }
@@ -57,8 +64,9 @@ func (a *ClusterID) Name() string {
 // generateInfraID take base and returns a ID that
 // - is of length maxLen
 // - only contains `alphanum` or `-`
-func generateInfraID(base string, maxLen int) string {
+func generateInfraID(base string, maxLen int) (string, error) {
 	maxBaseLen := maxLen - (randomLen + 1)
+	random := utilrand.String(randomLen)
 
 	// replace all characters that are not `alphanum` or `-` with `-`
 	re := regexp.MustCompile("[^A-Za-z0-9-]")
@@ -74,6 +82,19 @@ func generateInfraID(base string, maxLen int) string {
 	}
 	base = strings.TrimRight(base, "-")
 
+	// Use the value provided by the "OPENSHIFT_INSTALL_INFRA_ID_OVERRIDE" environment variable
+	// as the random part if it contains a string with 5 ('randomLen') lowercase characters and no vowels.
+	// This will match the possible values currently generated by 'utilrand.String(randomLen)'
+	if envInfraID, ok := os.LookupEnv("OPENSHIFT_INSTALL_INFRA_ID_OVERRIDE"); ok && envInfraID != "" {
+		logrus.Warn("Found override for 'InfraID'. Please be warned, this is not advised")
+		validInfraIDPattern := fmt.Sprintf("^([b-df-hj-np-tv-z0-9]){%d}$", randomLen)
+		validInfraIDRegex := regexp.MustCompile(validInfraIDPattern)
+		if !validInfraIDRegex.MatchString(envInfraID) {
+			return "", errors.Errorf("Invalid 'OPENSHIFT_INSTALL_INFRA_ID_OVERRIDE': '%s'", envInfraID)
+		}
+		random = envInfraID
+	}
+
 	// add random chars to the end to randomize
-	return fmt.Sprintf("%s-%s", base, utilrand.String(randomLen))
+	return fmt.Sprintf("%s-%s", base, random), nil
 }

pkg/asset/installconfig/clusterid_test.go

@@ -1,15 +1,18 @@
 package installconfig
 
 import (
+	"fmt"
+	"os"
+	"regexp"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_generateInfraID(t *testing.T) {
 	tests := []struct {
-		input string
-
+		input      string
+		envInfraID string
 		expLen     int
 		expNonRand string
 	}{{
@@ -31,10 +34,39 @@ func Test_generateInfraID(t *testing.T) {
 	}}
 	for _, test := range tests {
 		t.Run("", func(t *testing.T) {
-			got := generateInfraID(test.input, 27)
-			t.Log("InfraID", got)
-			assert.Equal(t, test.expLen, len(got))
-			assert.Equal(t, test.expNonRand, got[:len(got)-randomLen-1])
+			for _, expRand := range []string{"", "xxxx", "xxxxx", "xxxxa", "xxXxx", "xxxxxx"} {
+				envInfraID := ""
+				if expRand != "" {
+					envInfraID = fmt.Sprintf("%s", expRand)
+				}
+				os.Setenv("OPENSHIFT_INSTALL_INFRA_ID_OVERRIDE", envInfraID)
+				t.Log("OPENSHIFT_INSTALL_INFRA_ID_OVERRIDE", envInfraID)
+
+				got, err := generateInfraID(test.input, 27)
+				t.Log("InfraID", got)
+
+				randomIDPattern := fmt.Sprintf("^([b-df-hj-np-tv-z0-9]){%d}$", randomLen)
+				randomIDRegexp := regexp.MustCompile(randomIDPattern)
+
+				// Invalid "OPENSHIFT_INSTALL_INFRA_ID_OVERRIDE" configured
+				if envInfraID != "" && !randomIDRegexp.MatchString(envInfraID) {
+					assert.Error(t, err, "Invalid 'OPENSHIFT_INSTALL_INFRA_ID_OVERRIDE': '%s'", envInfraID)
+				} else {
+					infraIDPattern := fmt.Sprintf("^%s-([b-df-hj-np-tv-z0-9]){%d}$", test.expNonRand, randomLen)
+					infraIDRegexp := regexp.MustCompile(infraIDPattern)
+					// No "OPENSHIFT_INSTALL_INFRA_ID_OVERRIDE" env var configured (normal flow)
+					if envInfraID == "" {
+						assert.Regexp(t, infraIDRegexp, got)
+					}
+					// Valid "OPENSHIFT_INSTALL_INFRA_ID_OVERRIDE" configured
+					if infraIDRegexp.MatchString(envInfraID) {
+						assert.Equal(t, test.expNonRand+"-"+envInfraID, got)
+
+					}
+					assert.Equal(t, test.expLen, len(got))
+					assert.Equal(t, test.expNonRand, got[:len(got)-randomLen-1])
+				}
+			}
 		})
 	}
 }