fix(openshift): use env var instead of clusterversion status

Get the current OpenShift release version from the OPENSHIFT_RELEASE
environment variable since the behavior of the original source --
the ClusterVersion desired release status field -- has changed.

Signed-off-by: Nick Hale <[email protected]>

Author: Tyler Slaton

pkg/controller/operators/openshift/helpers.go

@@ -4,7 +4,9 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"os"
 	"strings"
+	"sync"
 
 	semver "github.com/blang/semver/v4"
 	configv1 "github.com/openshift/api/config/v1"
@@ -119,17 +121,17 @@ func transientErrors(err error) error {
 }
 
 func incompatibleOperators(ctx context.Context, cli client.Client) (skews, error) {
-	desired, err := desiredRelease(ctx, cli)
+	current, err := currentRelease(ctx)
 	if err != nil {
 		return nil, err
 	}
 
-	if desired == nil {
+	if current == nil {
 		// Note: This shouldn't happen
 		return nil, fmt.Errorf("failed to determine current OpenShift Y-stream release")
 	}
 
-	next, err := nextY(*desired)
+	next, err := nextY(*current)
 	if err != nil {
 		return nil, err
 	}
@@ -168,24 +170,39 @@ func incompatibleOperators(ctx context.Context, cli client.Client) (skews, error
 	return incompatible, nil
 }
 
-func desiredRelease(ctx context.Context, cli client.Client) (*semver.Version, error) {
-	cv := configv1.ClusterVersion{}
-	if err := cli.Get(ctx, client.ObjectKey{Name: "version"}, &cv); err != nil { // "version" is the name of OpenShift's ClusterVersion singleton
-		return nil, &transientError{fmt.Errorf("failed to get ClusterVersion: %w", err)}
+var (
+	openshiftRelease *semver.Version
+	releaseMutex     sync.Mutex
+)
+
+const (
+	releaseEnvVar = "OPENSHIFT_RELEASE"
+)
+
+func currentRelease(ctx context.Context) (*semver.Version, error) {
+	releaseMutex.Lock()
+	defer releaseMutex.Unlock()
+
+	if openshiftRelease != nil {
+		// We've already got the version
+		return openshiftRelease, nil
 	}
 
-	v := cv.Status.Desired.Version
-	if v == "" {
-		// The release version hasn't been set yet
-		return nil, fmt.Errorf("desired release version missing from ClusterVersion")
+	// Get the raw version from the OPENSHIFT_RELEASE environment variable
+	raw, ok := os.LookupEnv(releaseEnvVar)
+	if !ok {
+		// No env var set, try again later
+		return nil, fmt.Errorf(releaseEnvVar)
 	}
 
-	desired, err := semver.ParseTolerant(v)
+	release, err := semver.ParseTolerant(raw)
 	if err != nil {
 		return nil, fmt.Errorf("cluster version has invalid desired release version: %w", err)
 	}
 
-	return &desired, nil
+	openshiftRelease = &release
+
+	return openshiftRelease, nil
 }
 
 func nextY(v semver.Version) (semver.Version, error) {