Adding day1 MachineConfig utility (#917)

Adding standalone Day1 utility. Allows manually producing
day1 MachineConfig.

Makefile

@@ -156,6 +156,9 @@ manager-hub: $(shell find -name "*.go") go.mod go.sum  ## Build manager-hub bina
 worker: $(shell find -name "*.go") go.mod go.sum  ## Build worker binary.
 	go build -ldflags="-X main.Version=$(VERSION) -X main.GitCommit=$(GIT_COMMIT)" -o $@ ./cmd/worker
 
+day1-utility: $(shell find -name "*.go") go.mod go.sum  ## Build day1 binary
+	go build -ldflags="-X main.Version=$(VERSION) -X main.GitCommit=$(GIT_COMMIT)" -o $@ ./cmd/day1-utility
+
 .PHONY: run
 run: manifests generate fmt vet ## Run a controller from your host.
 	go run ./main.go

cmd/day1-utility/main.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/rh-ecosystem-edge/kernel-module-management/pkg/mcproducer"
+)
+
+var (
+	GitCommit = "undefined"
+	Version   = "undefined"
+)
+
+func customUsage() {
+	fmt.Fprintf(flag.CommandLine.Output(), "Usage: %s MC_NAME MCP_NAME KMOD_NAME IMAGE_NAME\n\n", os.Args[0])
+	fmt.Fprintln(flag.CommandLine.Output(), "Arguments:")
+	fmt.Fprintln(flag.CommandLine.Output(), "MC_NAME: name of the MachineConfig to be created")
+	fmt.Fprintln(flag.CommandLine.Output(), "MCP_NAME: MachineConfigPool name that should be referenced by MachineConfig")
+	fmt.Fprintln(flag.CommandLine.Output(), "KMOD_NAME: kernel module name, that should be unloaded (in-tree) and then loaded (oot)")
+	fmt.Fprintln(flag.CommandLine.Output(), "IMAGE_NAME: container image that contains kernel module .ko file")
+}
+
+func main() {
+	flag.Parse()
+	flag.Usage = customUsage
+
+	if flag.NArg() != 4 {
+		fmt.Println("Wrong number of arguments are provided", "num parameters", flag.NArg(), "git commit", GitCommit, "version", Version)
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	args := flag.Args()
+
+	yaml, err := mcproducer.ProduceMachineConfig(args[0], args[1], args[2], args[3])
+	if err != nil {
+		fmt.Println("failed to produce MachineConfig yaml", "error", err, "git commit", GitCommit, "version", Version)
+		os.Exit(1)
+	}
+
+	fmt.Printf("%s", yaml)
+}