motiejus
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undocker
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refactor go-flags initialization

main
Motiejus Jakštys 2021-05-24 00:11:58 +03:00
parent 861f0d319a
commit d7fb5140e8
10 changed files with 46 additions and 84 deletions
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8
internal/cmd/BUILD
View File

@ -1,8 +0,0 @@
load("@io_bazel_rules_go//go:def.bzl", "go_library")
go_library(
name = "go_default_library",
srcs = ["cmd.go"],
importpath = "github.com/motiejus/code/undocker/internal/cmd",
visibility = ["//src/undocker:__subpackages__"],
)

20
internal/cmd/cmd.go
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@ -1,20 +0,0 @@
package cmd
import (
"io"
"os"
)
// BaseCommand provides common fields to all commands.
type BaseCommand struct {
Stdin io.Reader
Stdout io.Writer
Stderr io.Writer
}
// Init initializes BaseCommand with default arguments
func (b *BaseCommand) Init() {
b.Stdin = os.Stdin
b.Stdout = os.Stdout
b.Stderr = os.Stderr
}

1
internal/cmdlxcconfig/BUILD
View File

@ -6,7 +6,6 @@ go_library(
importpath = "github.com/motiejus/code/undocker/internal/cmdlxcconfig",
visibility = ["//src/undocker:__subpackages__"],
deps = [
"//src/undocker/internal/cmd:go_default_library",
"//src/undocker/lxcconfig:go_default_library",
"@com_github_jessevdk_go_flags//:go_default_library",
"@org_uber_go_multierr//:go_default_library",

29
internal/cmdlxcconfig/cmdlxcconfig.go
View File

@ -2,10 +2,11 @@ package cmdlxcconfig
import (
"errors"
"fmt"
"io"
"os"
goflags "github.com/jessevdk/go-flags"
"github.com/motiejus/code/undocker/internal/cmd"
"github.com/motiejus/code/undocker/lxcconfig"
"go.uber.org/multierr"
)
@ -13,7 +14,8 @@ import (
// Command is "lxcconfig" command
type (
Command struct {
cmd.BaseCommand
Stdout io.Writer
PositionalArgs struct {
Infile goflags.Filename `long:"infile" description:"Input tarball"`
Outfile string `long:"outfile" description:"Output path, stdout is '-'"`
@ -21,9 +23,17 @@ type (
}
)
func NewCommand() *Command {
return &Command{
Stdout: os.Stdout,
}
}
func (*Command) ShortDesc() string { return "Create an LXC-compatible container configuration" }
func (*Command) LongDesc() string { return "" }
// Execute executes lxcconfig Command
func (c *Command) Execute(args []string) (err error) {
c.BaseCommand.Init()
if len(args) != 0 {
return errors.New("too many args")
}
@ -34,17 +44,18 @@ func (c *Command) Execute(args []string) (err error) {
}
defer func() { err = multierr.Append(err, rd.Close()) }()
var out *os.File
var out io.Writer
outf := string(c.PositionalArgs.Outfile)
if outf == "-" {
out = os.Stdout
if fname := string(c.PositionalArgs.Outfile); fname == "-" {
out = c.Stdout
} else {
out, err = os.Create(outf)
outf, err := os.Create(outf)
if err != nil {
return err
return fmt.Errorf("create: %w", err)
}
defer func() { err = multierr.Append(err, outf.Close()) }()
out = outf
}
defer func() { err = multierr.Append(err, out.Close()) }()
return lxcconfig.LXCConfig(rd, out)
}

2
internal/cmdrootfs/BUILD
View File

@ -6,7 +6,6 @@ go_library(
importpath = "github.com/motiejus/code/undocker/internal/cmdrootfs",
visibility = ["//src/undocker:__subpackages__"],
deps = [
"//src/undocker/internal/cmd:go_default_library",
"//src/undocker/rootfs:go_default_library",
"@com_github_jessevdk_go_flags//:go_default_library",
"@org_uber_go_multierr//:go_default_library",
@ -18,7 +17,6 @@ go_test(
srcs = ["cmdrootfs_test.go"],
embed = [":go_default_library"],
deps = [
"//src/undocker/internal/cmd:go_default_library",
"@com_github_jessevdk_go_flags//:go_default_library",
"@com_github_stretchr_testify//assert:go_default_library",
"@com_github_stretchr_testify//require:go_default_library",

34
internal/cmdrootfs/cmdrootfs.go
View File

@ -7,34 +7,37 @@ import (
"os"
goflags "github.com/jessevdk/go-flags"
"github.com/motiejus/code/undocker/internal/cmd"
"github.com/motiejus/code/undocker/rootfs"
"go.uber.org/multierr"
)
type (
// Command is "rootfs" command
Command struct {
cmd.BaseCommand
flattener func(io.ReadSeeker, io.Writer) error
Stdout io.Writer
PositionalArgs struct {
Infile goflags.Filename `long:"infile" description:"Input tarball"`
Outfile string `long:"outfile" description:"Output path, stdout is '-'"`
Infile goflags.Filename `long:"infile" desc:"Input tarball"`
Outfile string `long:"outfile" desc:"Output path, stdout is '-'"`
} `positional-args:"yes" required:"yes"`
flattener func(io.ReadSeeker, io.Writer) error
}
)
func NewCommand() *Command {
return &Command{
flattener: rootfs.Flatten,
Stdout: os.Stdout,
}
}
func (*Command) ShortDesc() string { return "Flatten a docker container image to a tarball" }
func (*Command) LongDesc() string { return "" }
// Execute executes rootfs Command
func (c *Command) Execute(args []string) (err error) {
if len(args) != 0 {
return errors.New("too many args")
}
if c.flattener == nil {
c.init()
}
rd, err := os.Open(string(c.PositionalArgs.Infile))
if err != nil {
@ -56,12 +59,3 @@ func (c *Command) Execute(args []string) (err error) {
return c.flattener(rd, out)
}
// init() initializes Command with the default options.
//
// Since constructors for sub-commands requires lots of boilerplate,
// command will initialize itself.
func (c *Command) init() {
c.BaseCommand.Init()
c.flattener = rootfs.Flatten
}

3
internal/cmdrootfs/cmdrootfs_test.go
View File

@ -8,7 +8,6 @@ import (
"testing"
goflags "github.com/jessevdk/go-flags"
"github.com/motiejus/code/undocker/internal/cmd"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
@ -57,7 +56,7 @@ func TestExecute(t *testing.T) {
t.Run(tt.name, func(t *testing.T) {
dir := t.TempDir()
var stdout bytes.Buffer
c := &Command{BaseCommand: cmd.BaseCommand{Stdout: &stdout}}
c := &Command{Stdout: &stdout}
if tt.fixture != nil {
tt.fixture(t, dir)
}

27
main.go
View File

@ -4,29 +4,22 @@ import (
"os"
goflags "github.com/jessevdk/go-flags"
"github.com/motiejus/code/undocker/internal/cmdlxcconfig"
"github.com/motiejus/code/undocker/internal/cmdrootfs"
)
type (
params struct {
RootFS cmdrootfs.Command `command:"rootfs" description:"Unpack a docker container image to a single filesystem tarball"`
LXCConfig cmdlxcconfig.Command `command:"lxcconfig" description:"Create an LXC-compatible container configuration"`
}
)
func main() {
if err := run(os.Args); err != nil {
flags := goflags.NewParser(nil, goflags.Default)
rootfs := cmdrootfs.NewCommand()
lxcconfig := cmdlxcconfig.NewCommand()
flags.AddCommand("rootfs", rootfs.ShortDesc(), rootfs.LongDesc(), rootfs)
flags.AddCommand("lxcconfig", lxcconfig.ShortDesc(), lxcconfig.LongDesc(), lxcconfig)
_, err := flags.Parse()
if err != nil {
os.Exit(1)
}
os.Exit(0)
}
func run(args []string) error {
var opts params
if _, err := goflags.ParseArgs(&opts, args[1:]); err != nil {
return err
}
return nil
}

4
rootfs/BUILD
View File

@ -9,10 +9,6 @@ go_library(
],
importpath = "github.com/motiejus/code/undocker/rootfs",
visibility = ["//visibility:public"],
deps = [
"//src/undocker/internal/bytecounter:go_default_library",
"@org_uber_go_multierr//:go_default_library",
],
)
go_test(

2
rootfs/doc.go
View File

@ -2,7 +2,7 @@
// tarball. It will go trough all layers in order and copy every file to the
// destination archive.
//
// Except it will also reasonably process those files.
// It will also reasonably process those files.
//
// == Non-directory will be copied only once ==
// A non-directory will be copied only once, only from within it's past