CORS-3446: Add instructions for obtaining correct binary

Update the warning message from the hostcrypt check to give more
specific instructions on how to obtain the correct binary and where to
run it.

Author: zaneb

pkg/hostcrypt/dynamic.go

@@ -0,0 +1,17 @@
+//go:build libvirt
+// +build libvirt
+
+package hostcrypt
+
+import "fmt"
+
+func allowFIPSCluster() error {
+	fipsEnabled, err := hostFIPSEnabled()
+	if err != nil {
+		return err
+	}
+	if fipsEnabled {
+		return nil
+	}
+	return fmt.Errorf("enable FIPS mode on the host")
+}

pkg/hostcrypt/hostcrypt.go

@@ -18,23 +18,27 @@ func VerifyHostTargetState(fips bool) error {
 	if !fips {
 		return nil
 	}
+
+	if err := allowFIPSCluster(); err != nil {
+		return fmt.Errorf("target cluster is in FIPS mode, %w", err)
+	}
+	return nil
+}
+
+func hostFIPSEnabled() (bool, error) {
 	if runtime.GOOS != "linux" {
-		return fmt.Errorf("target cluster is in FIPS mode, operation requires a Linux client")
+		return false, fmt.Errorf("operation requires a Linux client")
 	}
 
 	hostFIPSData, err := os.ReadFile(fipsFile)
 	if err != nil {
-		return fmt.Errorf("target cluster is in FIPS mode, but failed to read client FIPS state %s: %w", fipsFile, err)
+		return false, fmt.Errorf("failed to read client FIPS state %s: %w", fipsFile, err)
 	}
 
 	hostFIPS, err := strconv.ParseBool(strings.TrimSuffix(string(hostFIPSData), "\n"))
 	if err != nil {
-		return fmt.Errorf("target cluster is in FIPS mode, but failed to parse client FIPS state %s: %w", fipsFile, err)
-	}
-
-	if !hostFIPS {
-		return fmt.Errorf("target cluster is in FIPS mode, operation requires a FIPS enabled client")
+		return false, fmt.Errorf("failed to parse client FIPS state %s: %w", fipsFile, err)
 	}
 
-	return nil
+	return hostFIPS, nil
 }

pkg/hostcrypt/static.go

@@ -0,0 +1,17 @@
+//go:build !libvirt
+// +build !libvirt
+
+package hostcrypt
+
+import "fmt"
+
+const binaryInstructions = "To obtain a suitable binary, download the openshift-install-rhel8 archive from the client mirror, or extract the openshift-install-fips command from the release payload."
+
+func allowFIPSCluster() error {
+	hostMsg := ""
+	if fipsEnabled, err := hostFIPSEnabled(); err != nil || !fipsEnabled {
+		hostMsg = " on a host with FIPS enabled"
+	}
+	return fmt.Errorf("use the FIPS-capable installer binary for RHEL 8%s.\n%s",
+		hostMsg, binaryInstructions)
+}