github.com/cloud-foundations/dominator@v0.0.0-20221004181915-6e4fee580046/lib/net/configurator/resolvConf.go (about)

     1  package configurator
     2  
     3  import (
     4  	"bufio"
     5  	"bytes"
     6  	"fmt"
     7  	"io"
     8  	"path/filepath"
     9  
    10  	"github.com/Cloud-Foundations/Dominator/lib/fsutil"
    11  	hyper_proto "github.com/Cloud-Foundations/Dominator/proto/hypervisor"
    12  )
    13  
    14  func printResolvConf(writer io.Writer, subnet *hyper_proto.Subnet) error {
    15  	if subnet.DomainName != "" {
    16  		fmt.Fprintf(writer, "domain %s\n", subnet.DomainName)
    17  		fmt.Fprintf(writer, "search %s\n", subnet.DomainName)
    18  		fmt.Fprintln(writer)
    19  	}
    20  	for _, nameserver := range subnet.DomainNameServers {
    21  		fmt.Fprintf(writer, "nameserver %s\n", nameserver)
    22  	}
    23  	return nil
    24  }
    25  
    26  func updateResolvConf(rootDir string,
    27  	subnet *hyper_proto.Subnet) (bool, error) {
    28  	buffer := &bytes.Buffer{}
    29  	fmt.Fprintln(buffer,
    30  		"; /etc/resolv.conf -- created by SmallStack installer")
    31  	fmt.Fprintln(buffer) // Split to keep stupid linter happy.
    32  	if err := printResolvConf(buffer, subnet); err != nil {
    33  		return false, err
    34  	}
    35  	filename := filepath.Join(rootDir, "etc", "resolv.conf")
    36  	return fsutil.UpdateFile(buffer.Bytes(), filename)
    37  }
    38  
    39  func writeResolvConf(rootDir string, subnet *hyper_proto.Subnet) error {
    40  	filename := filepath.Join(rootDir, "etc", "resolv.conf")
    41  	file, err := fsutil.CreateRenamingWriter(filename, fsutil.PublicFilePerms)
    42  	if err != nil {
    43  		return err
    44  	}
    45  	defer file.Close()
    46  	writer := bufio.NewWriter(file)
    47  	fmt.Fprintln(writer,
    48  		"; /etc/resolv.conf -- created by SmallStack installer")
    49  	fmt.Fprintln(writer) // Split to keep stupid linter happy.
    50  	if err := printResolvConf(writer, subnet); err != nil {
    51  		return err
    52  	}
    53  	return writer.Flush()
    54  }