github.com/hugh712/snapd@v0.0.0-20200910133618-1a99902bd583/cmd/snap-bootstrap/main.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2019 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package main
    21  
    22  import (
    23  	"fmt"
    24  	"os"
    25  
    26  	"github.com/jessevdk/go-flags"
    27  
    28  	"github.com/snapcore/snapd/logger"
    29  )
    30  
    31  var (
    32  	shortHelp = "Bootstrap a Ubuntu Core system"
    33  	longHelp  = `
    34  snap-bootstrap is a tool to bootstrap Ubuntu Core from ephemeral systems
    35  such as initramfs.
    36  `
    37  
    38  	opts            struct{}
    39  	commandBuilders []func(*flags.Parser)
    40  )
    41  
    42  func init() {
    43  	err := logger.SimpleSetup()
    44  	if err != nil {
    45  		fmt.Fprintf(os.Stderr, "WARNING: failed to activate logging: %s\n", err)
    46  	}
    47  }
    48  
    49  func main() {
    50  	err := run(os.Args[1:])
    51  	if err != nil {
    52  		fmt.Fprintf(os.Stderr, "error: %s\n", err)
    53  		os.Exit(1)
    54  	}
    55  }
    56  
    57  func run(args []string) error {
    58  	if os.Getuid() != 0 {
    59  		return fmt.Errorf("please run as root")
    60  	}
    61  	logger.SimpleSetup()
    62  	return parseArgs(args)
    63  }
    64  
    65  func parseArgs(args []string) error {
    66  	p := parser()
    67  
    68  	_, err := p.ParseArgs(args)
    69  	return err
    70  }
    71  
    72  func parser() *flags.Parser {
    73  	p := flags.NewParser(&opts, flags.HelpFlag|flags.PassDoubleDash|flags.PassAfterNonOption)
    74  	p.ShortDescription = shortHelp
    75  	p.LongDescription = longHelp
    76  	for _, builder := range commandBuilders {
    77  		builder(p)
    78  	}
    79  	return p
    80  }
    81  
    82  func addCommandBuilder(builder func(*flags.Parser)) {
    83  	commandBuilders = append(commandBuilders, builder)
    84  }