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added network config

This commit is contained in:
Benjamin Böhmke 2019-11-29 19:53:17 +01:00
parent ce335164ff
commit d7e0591576
6 changed files with 310 additions and 4 deletions

3
.gitignore vendored
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@ -1 +1,2 @@
.idea/
.idea/
test_*

5
go.mod Normal file
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@ -0,0 +1,5 @@
module gitlab.com/bboehmke/raspi-alpine-builder
go 1.13
require github.com/stretchr/testify v1.4.0

13
go.sum Normal file
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@ -0,0 +1,13 @@
github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/iris-contrib/go.uuid v2.0.0+incompatible/go.mod h1:iz2lgM/1UnEf1kP0L/+fafWORmlnuysV2EMP8MW+qe0=
github.com/kataras/iris v11.1.1+incompatible/go.mod h1:ki9XPua5SyAJbIxDdsssxevgGrbpBmmvoQmo/A0IodY=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

171
network.go Normal file
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package alpine_builder
import (
"bufio"
"bytes"
"errors"
"fmt"
"io/ioutil"
"os"
"regexp"
"strings"
)
// network configuration
var networkConfig = "/data/etc/network/interfaces"
var networkInterface = "eth0"
// regular expressions
var reSectionStart = regexp.MustCompile("^(iface|mapping|auto|allow-|source)")
var reIface = regexp.MustCompile("^iface (\\w+) inet (\\w+)")
var reStaticAddress = regexp.MustCompile("^(\\s*)address ([0-9.]+)")
var reStaticNetmask = regexp.MustCompile("^(\\s*)netmask ([0-9.]+)")
var reStaticGateway = regexp.MustCompile("^(\\s*)gateway ([0-9.]+)")
// NetworkInfo represents the actual network configuration
type NetworkInfo struct {
IsStatic bool
Address string
Netmask string
Gateway string
}
// GetNetworkInfo from config file
func GetNetworkInfo() (*NetworkInfo, error) {
// load config file
file, err := os.Open(networkConfig)
if err != nil {
return nil, fmt.Errorf("failed to open network config: %w", err)
}
defer file.Close()
var info *NetworkInfo
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := strings.TrimSpace(scanner.Text())
// check for section start
if reSectionStart.MatchString(line) {
infLine := reIface.FindStringSubmatch(line)
if infLine != nil {
// interface found
if infLine[1] == networkInterface {
info = &NetworkInfo{
IsStatic: infLine[2] == "static",
}
}
} else {
// info set -> stop here
if info != nil {
break
}
}
} else if info != nil {
// interface config
address := reStaticAddress.FindStringSubmatch(line)
if address != nil {
info.Address = address[2]
}
netmask := reStaticNetmask.FindStringSubmatch(line)
if netmask != nil {
info.Netmask = netmask[2]
}
gateway := reStaticGateway.FindStringSubmatch(line)
if gateway != nil {
info.Gateway = gateway[2]
}
}
}
if info != nil {
return info, nil
}
return nil, errors.New("invalid network config")
}
// NetworkEnableDHCP configures the network to use DHCP client
func NetworkEnableDHCP() error {
// load config file
file, err := os.Open(networkConfig)
if err != nil {
return fmt.Errorf("failed to open network config: %w", err)
}
defer file.Close()
var buffer bytes.Buffer
var infFound bool
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := strings.TrimSpace(scanner.Text())
// check for section start
if reSectionStart.MatchString(line) {
infLine := reIface.FindStringSubmatch(line)
if infLine != nil {
// interface found
if infLine[1] == networkInterface {
infFound = true
buffer.WriteString(fmt.Sprintf("iface %s inet dhcp\n", networkInterface))
continue
}
} else {
if infFound {
infFound = false
}
}
buffer.WriteString(line + "\n")
} else if !infFound {
buffer.WriteString(line + "\n")
}
}
// write config file
return ioutil.WriteFile(networkConfig, buffer.Bytes(), os.ModePerm)
}
// NetworkSetStatic IP configuration
func NetworkSetStatic(address, netmask, gateway string) error {
// load config file
file, err := os.Open(networkConfig)
if err != nil {
return fmt.Errorf("failed to open network config: %w", err)
}
defer file.Close()
var buffer bytes.Buffer
var infFound bool
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := strings.TrimSpace(scanner.Text())
// check for section start
if reSectionStart.MatchString(line) {
infLine := reIface.FindStringSubmatch(line)
if infLine != nil {
// interface found
if infLine[1] == networkInterface {
infFound = true
buffer.WriteString(fmt.Sprintf("iface %s inet static\n", networkInterface))
buffer.WriteString(fmt.Sprintf(" address %s\n", address))
buffer.WriteString(fmt.Sprintf(" netmask %s\n", netmask))
buffer.WriteString(fmt.Sprintf(" gateway %s\n", gateway))
continue
}
} else {
if infFound {
infFound = false
}
}
buffer.WriteString(line + "\n")
} else if !infFound {
buffer.WriteString(line + "\n")
}
}
// write config file
return ioutil.WriteFile(networkConfig, buffer.Bytes(), os.ModePerm)
}

116
network_test.go Normal file
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package alpine_builder
import (
"io/ioutil"
"os"
"testing"
"github.com/stretchr/testify/assert"
)
func init() {
networkConfig = "test_interfaces"
}
func TestGetNetworkInfo(t *testing.T) {
ass := assert.New(t)
// file does not exist
_, err := GetNetworkInfo()
ass.EqualError(err, "failed to open network config: open test_interfaces: no such file or directory")
// invalid config file
ass.NoError(ioutil.WriteFile(networkConfig, []byte(""), os.ModePerm))
_, err = GetNetworkInfo()
ass.EqualError(err, "invalid network config")
// dynamic config
ass.NoError(ioutil.WriteFile(networkConfig, []byte(`auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp`), os.ModePerm))
info, err := GetNetworkInfo()
ass.NoError(err)
ass.False(info.IsStatic)
// static config
ass.NoError(ioutil.WriteFile(networkConfig, []byte(`auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 1.2.3.4
netmask 255.255.255.0
gateway 4.3.2.1`), os.ModePerm))
info, err = GetNetworkInfo()
ass.NoError(err)
ass.True(info.IsStatic)
ass.Equal("1.2.3.4", info.Address)
ass.Equal("255.255.255.0", info.Netmask)
ass.Equal("4.3.2.1", info.Gateway)
_ = os.Remove(networkConfig)
}
func TestNetworkEnableDHCP(t *testing.T) {
ass := assert.New(t)
// file does not exist
_, err := GetNetworkInfo()
ass.EqualError(err, "failed to open network config: open test_interfaces: no such file or directory")
ass.NoError(ioutil.WriteFile(networkConfig, []byte(`auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 1.2.3.4
netmask 255.255.255.0
gateway 4.3.2.1`), os.ModePerm))
ass.NoError(NetworkEnableDHCP())
data, err := ioutil.ReadFile(networkConfig)
ass.NoError(err)
ass.Equal(`auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
`, string(data))
_ = os.Remove(networkConfig)
}
func TestNetworkSetStatic(t *testing.T) {
ass := assert.New(t)
// file does not exist
_, err := GetNetworkInfo()
ass.EqualError(err, "failed to open network config: open test_interfaces: no such file or directory")
ass.NoError(ioutil.WriteFile(networkConfig, []byte(`auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp`), os.ModePerm))
ass.NoError(NetworkSetStatic("1.2.3.4", "255.255.255.0", "4.3.2.1"))
data, err := ioutil.ReadFile(networkConfig)
ass.NoError(err)
ass.Equal(`auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 1.2.3.4
netmask 255.255.255.0
gateway 4.3.2.1
`, string(data))
_ = os.Remove(networkConfig)
}

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@ -99,7 +99,7 @@ EOF
# prepare network
chroot_exec rc-update add networking default
ln -fs /data/etc/interfaces ${ROOTFS_PATH}/etc/network/interfaces
ln -fs /data/etc/network/interfaces ${ROOTFS_PATH}/etc/network/interfaces
# run local before network -> local brings up the interface
sed -i '/^\tneed/ s/$/ local/' ${ROOTFS_PATH}/etc/init.d/networking
@ -200,8 +200,8 @@ root_pw=\$(mkpasswd -m sha-512 -s "${DEFAULT_ROOT_PASSWORD}")
echo "root:\${root_pw}:0:0:::::" > /data/etc/shadow
# interface
if [ ! -f /data/etc/interfaces ]; then
cat > /data/etc/interfaces <<EOF2
if [ ! -f /data/etc/network/interfaces ]; then
cat > /data/etc/network/interfaces <<EOF2
auto lo
iface lo inet loopback