Mantle: use Butane libs

mantle/cmd/kola/qemuexec.go

@@ -20,7 +20,6 @@ import (
 	"context"
 	"fmt"
 	"io/ioutil"
-	"os/exec"
 	"path/filepath"
 	"strings"
 
@@ -30,6 +29,7 @@ import (
 	"github.com/coreos/mantle/kola"
 	"github.com/coreos/mantle/platform"
 	"github.com/coreos/mantle/platform/conf"
+	"github.com/coreos/mantle/util"
 )
 
 var (
@@ -205,11 +205,15 @@ func runQemuExec(cmd *cobra.Command, args []string) error {
 			return err
 		}
 		defer tmpf.Close()
-		cmd := exec.Command("fcct", butane)
-		cmd.Stdout = tmpf
-		if err = cmd.Run(); err != nil {
+
+		out, err := util.ButaneFileToIgnition(butane)
+		if err != nil {
 			return err
 		}
+		if _, err := tmpf.Write(out); err != nil {
+			return err
+		}
+
 		ignition = tmpf.Name()
 	}
 

mantle/go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/aliyun/alibaba-cloud-sdk-go v0.0.0-20190929091402-5711055976b5
 	github.com/aliyun/aliyun-oss-go-sdk v2.0.3+incompatible
 	github.com/aws/aws-sdk-go v1.34.28
+	github.com/coreos/butane v0.12.1
 	github.com/coreos/go-semver v0.3.0
 	github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e
 	github.com/coreos/go-systemd/v22 v22.0.0
@@ -32,7 +33,7 @@ require (
 	github.com/pin/tftp v2.1.0+incompatible
 	github.com/pkg/errors v0.9.1
 	github.com/spf13/cobra v0.0.6
-	github.com/spf13/pflag v1.0.3
+	github.com/spf13/pflag v1.0.5
 	github.com/ulikunitz/xz v0.5.4
 	github.com/vincent-petithory/dataurl v0.0.0-20191104211930-d1553a71de50
 	github.com/vishvananda/netlink v0.0.0-20150710184826-9cff81214893

mantle/util/butane.go

@@ -0,0 +1,58 @@
+// Copyright 2021 Red Hat, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package util
+
+import (
+	"bufio"
+	"io"
+	"io/ioutil"
+	"os"
+	"strings"
+
+	"github.com/coreos/butane/config"
+	"github.com/coreos/butane/config/common"
+)
+
+// ButaneStringToIgniton takes a string and translates it into Ignition data.
+func ButaneStringToIgnition(s string) ([]byte, error) {
+	r := strings.NewReader(s)
+	return ButaneReaderToIgnition(r)
+}
+
+// ButaneFileToIgnition reads a file and translates it into Ignition data.
+func ButaneFileToIgnition(fname string) ([]byte, error) {
+	in, err := os.Open(fname)
+	if err != nil {
+		return nil, err
+	}
+	defer in.Close()
+	b := bufio.NewReader(in)
+
+	return ButaneReaderToIgnition(b)
+}
+
+// ButaneReaderToIgnition takes an io.Reader and translates it into Ignition.
+func ButaneReaderToIgnition(r io.Reader) ([]byte, error) {
+	data, err := ioutil.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+	out, _, err := config.TranslateBytes(data,
+		common.TranslateBytesOptions{
+			Pretty: true,
+			Strict: true,
+		})
+	return out, err
+}