airship/vino
Code Issues Proposed changes

Merge "Add base IPAM support"

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This commit is contained in:
Zuul 2021-01-22 19:36:56 +00:00 committed by Gerrit Code Review
commit f9d29a91a1
4 changed files with 653 additions and 1 deletions
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2
go.mod
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@ -10,7 +10,7 @@ require (
github.com/onsi/ginkgo v1.14.2
github.com/onsi/gomega v1.10.2
github.com/prometheus/common v0.10.0
github.com/stretchr/testify v1.6.1 // indirect
github.com/stretchr/testify v1.6.1
go.uber.org/zap v1.15.0
golang.org/x/sys v0.0.0-20200814200057-3d37ad5750ed // indirect
golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect

80
pkg/ipam/errors.go Normal file
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@ -0,0 +1,80 @@
/*
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
https://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 ipam
import (
"fmt"
)
// ErrSubnetNotAllocated returned if the subnet is not registered in IPAM
type ErrSubnetNotAllocated struct {
Subnet string
}
// ErrSubnetRangeOverlapsWithExistingRange returned if the subnet's range
// overlaps (partially or completely) with an already added range in that subnet
type ErrSubnetRangeOverlapsWithExistingRange struct {
Subnet string
SubnetRange Range
}
// ErrSubnetRangeNotAllocated returned if the subnet's range is not registered in IPAM
type ErrSubnetRangeNotAllocated struct {
Subnet string
SubnetRange Range
}
// ErrSubnetRangeExhausted returned if the subnet's range has no unallocated IPs
type ErrSubnetRangeExhausted struct {
Subnet string
SubnetRange Range
}
// ErrInvalidIPAddress returned if an IP address string is malformed
type ErrInvalidIPAddress struct {
IP string
}
// ErrNotSupported returned if unsupported address types are used
type ErrNotSupported struct {
Message string
}
func (e ErrSubnetNotAllocated) Error() string {
return fmt.Sprintf("IPAM subnet %s not allocated", e.Subnet)
}
func (e ErrSubnetRangeOverlapsWithExistingRange) Error() string {
return fmt.Sprintf("IPAM range [%s,%s] in subnet %s overlaps with an existing range",
e.SubnetRange.Start, e.SubnetRange.Stop, e.Subnet)
}
func (e ErrSubnetRangeNotAllocated) Error() string {
return fmt.Sprintf("IPAM range [%s,%s] in subnet %s is not allocated",
e.SubnetRange.Start, e.SubnetRange.Stop, e.Subnet)
}
func (e ErrSubnetRangeExhausted) Error() string {
return fmt.Sprintf("IPAM range [%s,%s] in subnet %s is exhausted",
e.SubnetRange.Start, e.SubnetRange.Stop, e.Subnet)
}
func (e ErrInvalidIPAddress) Error() string {
return fmt.Sprintf("IP address %s is invalid", e.IP)
}
func (e ErrNotSupported) Error() string {
return fmt.Sprintf("%s", e.Message)
}

219
pkg/ipam/ipam.go Normal file
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@ -0,0 +1,219 @@
/*
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
https://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 ipam
import (
"net"
"strings"
"unsafe"
"github.com/go-logr/logr"
"k8s.io/apimachinery/pkg/runtime"
"sigs.k8s.io/controller-runtime/pkg/client"
)
// Ipam provides IPAM reservation, backed by IPPool CRs
type Ipam struct {
Log logr.Logger
Scheme *runtime.Scheme
Client client.Client
ippools map[string]*IPPool
}
// IPPool tracks allocation ranges and statuses within a specific
// subnet IPv4 or IPv6 subnet. It has a set of ranges of IPs
// within the subnet from which IPs can be allocated by IPAM,
// and a set of IPs that are currently allocated already.
type IPPool struct {
Subnet string
Ranges []Range
AllocatedIPs []string
}
// Range has (inclusive) bounds within a subnet from which IPs can be allocated
type Range struct {
Start string
Stop string
}
// NewIpam initializes an empty IPAM configuration.
// TODO: persist and refresh state from the API server
// TODO: add ability to remove IP addresses and ranges
func NewIpam() *Ipam {
ippools := make(map[string]*IPPool)
return &Ipam{
ippools: ippools,
}
}
// AddSubnetRange adds a range within a subnet for IP allocation
// TODO error: invalid range for subnet
// TODO error: range overlaps with existing range or subnet overlaps with existing subnet
func (i *Ipam) AddSubnetRange(subnet string, subnetRange Range) error {
// Does the subnet already exist? (this is fine)
ippool, exists := i.ippools[subnet]
if !exists {
ippool = &IPPool{
Subnet: subnet,
Ranges: []Range{subnetRange}, // TODO DeepCopy()
AllocatedIPs: []string{},
}
i.ippools[subnet] = ippool
} else {
// Does the subnet's requested range already exist? (this should fail)
exists = false
for _, r := range ippool.Ranges {
if r == subnetRange {
exists = true
break
}
}
if exists {
return ErrSubnetRangeOverlapsWithExistingRange{Subnet: subnet, SubnetRange: subnetRange}
}
}
ippool.Ranges = append(ippool.Ranges, subnetRange)
return nil
}
// AllocateIP allocates an IP from a range and return it
func (i *Ipam) AllocateIP(subnet string, subnetRange Range) (string, error) {
// NOTE/TODO: this is not threadsafe, which is fine because
// the final impl will use the api server as the backend, not local.
ippool, exists := i.ippools[subnet]
if !exists {
return "", ErrSubnetNotAllocated{Subnet: subnet}
}
// Make sure the range has been allocated within the subnet
var match bool
for _, r := range ippool.Ranges {
if r == subnetRange {
match = true
break
}
}
if !match {
return "", ErrSubnetRangeNotAllocated{Subnet: subnet, SubnetRange: subnetRange}
}
ip, err := findFreeIPInRange(ippool, subnetRange)
if err != nil {
return "", err
}
ippool.AllocatedIPs = append(ippool.AllocatedIPs, ip)
return ip, nil
}
// This converts IP ranges/addresses into iterable ints,
// steps through them looking for one that that is not already
// in use, converts it back to a string and returns it.
// It does not itself add it to the list of assigned IPs.
func findFreeIPInRange(ippool *IPPool, subnetRange Range) (string, error) {
allocatedIPSet := sliceToMap(ippool.AllocatedIPs)
intToString := intToIPv4String
if strings.Contains(ippool.Subnet, ":") {
intToString = intToIPv6String
}
// Step through the range looking for free IPs
start, err := ipStringToInt(subnetRange.Start)
if err != nil {
return "", err
}
stop, err := ipStringToInt(subnetRange.Stop)
if err != nil {
return "", err
}
for ip := start; ip <= stop; ip++ {
_, in := allocatedIPSet[intToString(ip)]
if !in {
// Found an unallocated IP
return intToString(ip), nil
}
}
return "", ErrSubnetRangeExhausted{ippool.Subnet, subnetRange}
}
// Create a map[string]struct{} representation of a string slice,
// for efficient set lookups
func sliceToMap(slice []string) map[string]struct{} {
m := map[string]struct{}{}
for _, s := range slice {
m[s] = struct{}{}
}
return m
}
// Convert an IPV4 or IPV6 address string to an easily iterable uint64.
// For IPV4 addresses, this captures the full address (padding the MSB with 0's)
// For IPV6 addresses, this captures the most significant 8 bytes,
// and excludes the 8-byte interface identifier.
func ipStringToInt(ipString string) (uint64, error) {
ip := net.ParseIP(ipString)
if ip == nil {
return 0, ErrInvalidIPAddress{ipString}
}
var bytes []byte
if ip.To4() != nil {
// IPv4
bytes = append(make([]byte, 4), ip.To4()...)
} else {
// IPv6
bytes = ip.To16()[:8]
}
return byteArrayToInt(bytes), nil
}
func intToIPv4String(i uint64) string {
bytes := intToByteArray(i)
ip := net.IPv4(bytes[4], bytes[5], bytes[6], bytes[7])
return ip.String()
}
func intToIPv6String(i uint64) string {
// Pad with 8 more bytes of zeros on the right for the hosts's interface,
// which will not be determined by IPAM.
bytes := append(intToByteArray(i), make([]byte, 8)...)
var ip net.IP = bytes
return ip.String()
}
// Convert an uint64 into 8 bytes, with most significant byte first
// Based on https://gist.github.com/ecoshub/5be18dc63ac64f3792693bb94f00662f
func intToByteArray(num uint64) []byte {
size := 8
arr := make([]byte, size)
for i := 0; i < size; i++ {
byt := *(*uint8)(unsafe.Pointer(uintptr(unsafe.Pointer(&num)) + uintptr(i)))
arr[size-i-1] = byt
}
return arr
}
// Convert an 8-byte array to an uint64
// Based on https://gist.github.com/ecoshub/5be18dc63ac64f3792693bb94f00662f
func byteArrayToInt(arr []byte) uint64 {
val := uint64(0)
size := 8
for i := 0; i < size; i++ {
*(*uint8)(unsafe.Pointer(uintptr(unsafe.Pointer(&val)) + uintptr(size-i-1))) = arr[i]
}
return val
}

353
pkg/ipam/ipam_test.go Normal file
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@ -0,0 +1,353 @@
/*
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
https://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 ipam
import (
"math"
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestAllocateIP(t *testing.T) {
tests := []struct {
name, subnet, expectedErr string
subnetRange Range
}{
{
name: "success ipv4",
subnet: "10.0.0.0/16",
subnetRange: Range{"10.0.1.0", "10.0.1.9"},
},
{
name: "success ipv6",
subnet: "2600:1700:b030:0000::/72",
subnetRange: Range{"2600:1700:b030:0000::", "2600:1700:b030:0009::"},
},
{
name: "error subnet not allocated ipv4",
subnet: "10.0.0.0/20",
subnetRange: Range{"10.0.1.0", "10.0.1.9"},
expectedErr: "IPAM subnet 10.0.0.0/20 not allocated",
},
{
name: "error subnet not allocated ipv6",
subnet: "2600:1700:b030:0000::/80",
subnetRange: Range{"2600:1700:b030:0000::", "2600:1700:b030:0009::"},
expectedErr: "IPAM subnet 2600:1700:b030:0000::/80 not allocated",
},
{
name: "error range not allocated ipv4",
subnet: "10.0.0.0/16",
subnetRange: Range{"10.0.2.0", "10.0.2.9"},
expectedErr: "IPAM range [10.0.2.0,10.0.2.9] in subnet 10.0.0.0/16 is not allocated",
},
{
name: "error range not allocated ipv6",
subnet: "2600:1700:b030:0000::/72",
subnetRange: Range{"2600:1700:b030:0000::", "2600:1700:b030:1111::"},
expectedErr: "IPAM range [2600:1700:b030:0000::,2600:1700:b030:1111::] " +
"in subnet 2600:1700:b030:0000::/72 is not allocated",
},
{
name: "error range exhausted ipv4",
subnet: "192.168.0.0/1",
subnetRange: Range{"192.168.0.0", "192.168.0.0"},
expectedErr: "IPAM range [192.168.0.0,192.168.0.0] in subnet 192.168.0.0/1 is exhausted",
},
{
name: "error range exhausted ipv6",
subnet: "2600:1700:b031:0000::/64",
subnetRange: Range{"2600:1700:b031:0000::", "2600:1700:b031:0000::"},
expectedErr: "IPAM range [2600:1700:b031:0000::,2600:1700:b031:0000::] " +
"in subnet 2600:1700:b031:0000::/64 is exhausted",
},
}
for _, tt := range tests {
tt := tt
t.Run(tt.name, func(t *testing.T) {
ipammer := NewIpam()
// Pre-populate IPAM with some precondition test data
err := ipammer.AddSubnetRange("10.0.0.0/16", Range{"10.0.1.0", "10.0.1.9"})
require.NoError(t, err)
err = ipammer.AddSubnetRange("2600:1700:b030:0000::/72", Range{"2600:1700:b030:0000::", "2600:1700:b030:0009::"})
require.NoError(t, err)
err = ipammer.AddSubnetRange("192.168.0.0/1", Range{"192.168.0.0", "192.168.0.0"})
require.NoError(t, err)
err = ipammer.AddSubnetRange("2600:1700:b031:0000::/64", Range{"2600:1700:b031:0000::", "2600:1700:b031:0000::"})
require.NoError(t, err)
_, err = ipammer.AllocateIP("192.168.0.0/1", Range{"192.168.0.0", "192.168.0.0"})
require.NoError(t, err)
_, err = ipammer.AllocateIP("2600:1700:b031:0000::/64", Range{"2600:1700:b031:0000::", "2600:1700:b031:0000::"})
require.NoError(t, err)
ip, err := ipammer.AllocateIP(tt.subnet, tt.subnetRange)
if tt.expectedErr != "" {
assert.Equal(t, "", ip)
require.Error(t, err)
assert.Contains(t, err.Error(), tt.expectedErr)
} else {
require.NoError(t, err)
assert.NotEmpty(t, ip)
}
})
}
}
// Test some error handling that is not captured by TestAllocateIP
func TestAddSubnetRange(t *testing.T) {
tests := []struct {
name, subnet, expectedErr string
subnetRange Range
}{
{
name: "success",
subnet: "10.0.0.0/16",
subnetRange: Range{"10.0.2.0", "10.0.2.9"},
expectedErr: "",
},
{
name: "error range already exists",
subnet: "10.0.0.0/16",
subnetRange: Range{"10.0.1.0", "10.0.1.9"},
expectedErr: "IPAM range [10.0.1.0,10.0.1.9] in subnet 10.0.0.0/16 overlaps",
},
// TODO: check for partially overlapping ranges and subnets
}
for _, tt := range tests {
tt := tt
t.Run(tt.name, func(t *testing.T) {
ipammer := NewIpam()
// Pre-populate IPAM with some precondition test data
err := ipammer.AddSubnetRange("10.0.0.0/16", Range{"10.0.1.0", "10.0.1.9"})
require.NoError(t, err)
err = ipammer.AddSubnetRange(tt.subnet, tt.subnetRange)
if tt.expectedErr != "" {
require.Error(t, err)
assert.Contains(t, err.Error(), tt.expectedErr)
} else {
require.NoError(t, err)
}
})
}
}
func TestFindFreeIPInRange(t *testing.T) {
tests := []struct {
name string
subnet string
subnetRange Range
out string
expectedErr string
}{
{
name: "ip available IPv4",
subnet: "10.0.0.0/16",
subnetRange: Range{"10.0.1.0", "10.0.1.10"},
out: "10.0.1.0",
},
{
name: "ip unavailable IPv4",
subnet: "10.0.0.0/16",
subnetRange: Range{"10.0.2.0", "10.0.2.0"},
out: "",
expectedErr: "IPAM range [10.0.2.0,10.0.2.0] in subnet 10.0.0.0/16 is exhausted",
},
{
name: "ip available IPv6",
subnet: "2600:1700:b030:0000::/64",
subnetRange: Range{"2600:1700:b030:1001::", "2600:1700:b030:1009::"},
out: "2600:1700:b030:1001::",
},
{
name: "ip unavailable IPv6",
subnet: "2600:1700:b031::/64",
subnetRange: Range{"2600:1700:b031::", "2600:1700:b031::"},
expectedErr: "IPAM range [2600:1700:b031::,2600:1700:b031::] " +
"in subnet 2600:1700:b031::/64 is exhausted",
},
}
for _, tt := range tests {
tt := tt
t.Run(tt.name, func(t *testing.T) {
ippool := IPPool{
Subnet: tt.subnet,
// One available and one unavailable range each for ipv4/6
Ranges: []Range{
{"10.0.1.0", "10.0.1.10"},
{"10.0.2.0", "10.0.2.0"},
{"2600:1700:b030:1001::", "2600:1700:b030:1009::"},
{"2600:1700:b031::", "2600:1700:b031::"},
},
AllocatedIPs: []string{"10.0.2.0", "2600:1700:b031::"},
}
actual, err := findFreeIPInRange(&ippool, tt.subnetRange)
if tt.expectedErr != "" {
require.Error(t, err)
assert.Contains(t, err.Error(), tt.expectedErr)
} else {
require.NoError(t, err)
assert.Equal(t, tt.out, actual)
}
})
}
}
func TestSliceToMap(t *testing.T) {
tests := []struct {
name string
in []string
out map[string]struct{}
}{
{
name: "empty slice",
in: []string{},
out: map[string]struct{}{},
},
{
name: "one-element slice",
in: []string{"foo"},
out: map[string]struct{}{"foo": {}},
},
{
name: "two-element slice",
in: []string{"foo", "bar"},
out: map[string]struct{}{"foo": {}, "bar": {}},
},
}
for _, tt := range tests {
tt := tt
t.Run(tt.name, func(t *testing.T) {
actual := sliceToMap(tt.in)
assert.Equal(t, tt.out, actual)
})
}
}
func TestIPStringToInt(t *testing.T) {
tests := []struct {
name string
in string
out uint64
expectedErr string
}{
{
name: "valid IPv4 address",
in: "1.0.0.1",
out: uint64(math.Pow(2, 24) + 1),
},
{
name: "invalid IPv4 address",
in: "1.0.0.1.1",
out: 0,
expectedErr: " is invalid",
},
{
name: "valid IPv6 address",
in: "0001:0000:0000:0001::",
out: uint64(math.Pow(2, 48) + 1),
},
{
name: "invalid IPv6 address",
in: "1000:0000:0000:foobar::",
out: 0,
expectedErr: " is invalid",
},
}
for _, tt := range tests {
tt := tt
t.Run(tt.name, func(t *testing.T) {
actual, err := ipStringToInt(tt.in)
if tt.expectedErr != "" {
require.Error(t, err)
assert.Empty(t, tt.out)
assert.Contains(t, err.Error(), tt.expectedErr)
} else {
require.NoError(t, err)
assert.Equal(t, tt.out, actual)
}
})
}
}
func TestIntToByteArray(t *testing.T) {
tests := []struct {
name string
in uint64
out []byte
}{
{
name: "zeros",
in: 0,
out: make([]byte, 8),
},
{
name: "IPv4 255's",
in: uint64(math.Pow(2, 32) - 1),
out: []byte{0, 0, 0, 0, 255, 255, 255, 255},
},
{
name: "value in the middle",
in: 512,
out: []byte{0, 0, 0, 0, 0, 0, 2, 0},
},
}
for _, tt := range tests {
tt := tt
t.Run(tt.name, func(t *testing.T) {
actual := intToByteArray(tt.in)
assert.Equal(t, tt.out, actual)
})
}
}
func TestByteArrayToInt(t *testing.T) {
tests := []struct {
name string
in []byte
out uint64
}{
{
name: "zeros",
in: make([]byte, 8),
out: 0,
},
{
name: "255's",
in: []byte{0, 0, 0, 0, 255, 255, 255, 255},
out: uint64(math.Pow(2, 32) - 1),
},
{
name: "value in the middle",
in: []byte{0, 0, 0, 0, 0, 0, 2, 0},
out: 512,
},
}
for _, tt := range tests {
tt := tt
t.Run(tt.name, func(t *testing.T) {
actual := byteArrayToInt(tt.in)
assert.Equal(t, tt.out, actual)
})
}
}