added netbox api implementation

netbox/netbox.go

@@ -0,0 +1,276 @@
+package netbox
+
+import (
+	"git.giftfish.de/ston1th/netalloc"
+
+	"crypto/tls"
+	"encoding/json"
+	"errors"
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+	"time"
+)
+
+type result struct {
+	ID int `json:"id"`
+}
+
+type resultList struct {
+	Results []result `json:"results"`
+}
+
+type ip struct {
+	Address string `json:"address"`
+}
+
+type detail struct {
+	Detail string `json:"detail"`
+}
+
+type Allocator struct {
+	httpClient *http.Client
+	token      string
+	prefix     string
+	endpoint   string
+	insecure   bool
+
+	prefixURL string
+	prefixNet *net.IPNet
+}
+
+type Option func(*Allocator)
+
+func WithHTTPClient(c *http.Client) Option {
+	return func(a *Allocator) {
+		a.httpClient = c
+	}
+}
+
+func WithEndpoint(endpoint string) Option {
+	return func(a *Allocator) {
+		a.endpoint = endpoint
+	}
+}
+
+func WithToken(token string) Option {
+	return func(a *Allocator) {
+		a.token = "Token " + token
+	}
+}
+
+func WithInsecureClient(insecure bool) Option {
+	return func(a *Allocator) {
+		a.insecure = insecure
+	}
+}
+
+func WithPrefix(prefix string) Option {
+	return func(a *Allocator) {
+		a.prefix = prefix
+	}
+}
+
+var (
+	ErrMissingPrefix   = errors.New("missing prefix config")
+	ErrMissingEndpoint = errors.New("missing endpoint config")
+	ErrMissingToken    = errors.New("missing token config")
+
+	ErrPrefixNotFound       = errors.New("prefix not found")
+	ErrIPNotFound           = errors.New("ip not found")
+	ErrUnexpectedStatusCode = errors.New("unexpected status code")
+)
+
+func NewAllocator(opts ...Option) (netalloc.Allocator, error) {
+	a := &Allocator{}
+	for _, opt := range opts {
+		opt(a)
+	}
+	if a.httpClient == nil {
+		a.httpClient = &http.Client{Transport: &http.Transport{
+			DialContext: (&net.Dialer{
+				Timeout: 30 * time.Second,
+			}).DialContext,
+			TLSClientConfig: &tls.Config{
+				InsecureSkipVerify: a.insecure,
+			},
+		}}
+	}
+	if a.prefix == "" {
+		return nil, ErrMissingPrefix
+	}
+	if a.endpoint == "" {
+		return nil, ErrMissingEndpoint
+	}
+	if a.token == "" {
+		return nil, ErrMissingToken
+	}
+	_, prefixnet, err := net.ParseCIDR(a.prefix)
+	if err != nil {
+		return nil, err
+	}
+	a.prefixNet = prefixnet
+
+	v := url.Values{
+		"prefix": []string{a.prefix},
+		"limit":  []string{"1"},
+	}
+	a.prefixURL = a.endpoint + "/api/ipam/prefixes/?" + v.Encode()
+	return a, nil
+}
+
+// SetStore is a no-op
+func (a *Allocator) SetStore(_ netalloc.Store) {}
+
+func (a *Allocator) prefixID() (id string, err error) {
+	req, err := http.NewRequest("GET", a.prefixURL, nil)
+	if err != nil {
+		return
+	}
+	req.Header.Set("Authorization", a.token)
+	resp, err := a.httpClient.Do(req)
+	if err != nil {
+		return
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode == http.StatusForbidden {
+		var d detail
+		err = json.NewDecoder(resp.Body).Decode(&d)
+		if err != nil {
+			return
+		}
+		return "", errors.New(d.Detail)
+	}
+	var rl resultList
+	err = json.NewDecoder(resp.Body).Decode(&rl)
+	if err != nil {
+		return
+	}
+	if len(rl.Results) == 0 {
+		return "", ErrPrefixNotFound
+	}
+	return strconv.Itoa(rl.Results[0].ID), nil
+}
+
+func (a *Allocator) Alloc() (*net.IPAddr, error) {
+	cidr, err := a.AllocCIDR()
+	if err != nil {
+		return nil, err
+	}
+	ip, _, err := net.ParseCIDR(cidr)
+	if err != nil {
+		return nil, err
+	}
+	return &net.IPAddr{IP: ip}, nil
+}
+
+func (a *Allocator) AllocCIDR() (cidr string, err error) {
+	id, err := a.prefixID()
+	if err != nil {
+		return
+	}
+
+	url := a.endpoint + "/api/ipam/prefixes/" + id + "/available-ips/"
+	req, err := http.NewRequest("POST", url, nil)
+	if err != nil {
+		return
+	}
+	req.Header.Set("Authorization", a.token)
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := a.httpClient.Do(req)
+	if err != nil {
+		return
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode == http.StatusNoContent {
+		return "", netalloc.ErrPrefixFull
+	}
+	if resp.StatusCode == http.StatusCreated {
+		var ip ip
+		err = json.NewDecoder(resp.Body).Decode(&ip)
+		if err != nil {
+			return
+		}
+		return ip.Address, nil
+	}
+	return "", ErrUnexpectedStatusCode
+}
+
+func (a *Allocator) ipID(cidr string) (id string, err error) {
+	v := url.Values{
+		"address": []string{cidr},
+		"limit":   []string{"1"},
+	}
+	url := a.endpoint + "/api/ipam/ip-addresses/?" + v.Encode()
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return
+	}
+	req.Header.Set("Authorization", a.token)
+	resp, err := a.httpClient.Do(req)
+	if err != nil {
+		return
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode == http.StatusForbidden {
+		var d detail
+		err = json.NewDecoder(resp.Body).Decode(&d)
+		if err != nil {
+			return
+		}
+		return "", errors.New(d.Detail)
+	}
+	var rl resultList
+	err = json.NewDecoder(resp.Body).Decode(&rl)
+	if err != nil {
+		return
+	}
+	if len(rl.Results) == 0 {
+		return "", ErrIPNotFound
+	}
+	return strconv.Itoa(rl.Results[0].ID), nil
+}
+
+func (a *Allocator) Free(ip *net.IPAddr) error {
+	return a.FreeCIDR(a.CIDR(ip))
+}
+
+func (a *Allocator) FreeCIDR(cidr string) (err error) {
+	id, err := a.ipID(cidr)
+	if err == ErrIPNotFound {
+		return nil
+	}
+	if err != nil {
+		return
+	}
+
+	url := a.endpoint + "/api/ipam/ip-addresses/" + id + "/"
+	req, err := http.NewRequest("DELETE", url, nil)
+	if err != nil {
+		return
+	}
+	req.Header.Set("Authorization", a.token)
+	resp, err := a.httpClient.Do(req)
+	if err != nil {
+		return
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode == http.StatusForbidden {
+		var d detail
+		err = json.NewDecoder(resp.Body).Decode(&d)
+		if err != nil {
+			return
+		}
+		return errors.New(d.Detail)
+	}
+	if resp.StatusCode == http.StatusNoContent ||
+		resp.StatusCode == http.StatusNotFound {
+		return nil
+	}
+	return ErrUnexpectedStatusCode
+}
+
+func (a *Allocator) CIDR(ip *net.IPAddr) string {
+	return netalloc.CIDR(a.prefixNet, ip)
+}