feat: add hetzner cloud provider

README.md

@@ -25,6 +25,7 @@ function.
  * Amazon AWS [Config options](https://github.com/hashicorp/go-discover/blob/8b3ddf4/provider/aws/aws_discover.go#L19-L34)
  * DigitalOcean [Config options](https://github.com/hashicorp/go-discover/blob/8b3ddf4/provider/digitalocean/digitalocean_discover.go#L22-L30)
  * Google Cloud [Config options](https://github.com/hashicorp/go-discover/blob/8b3ddf4/provider/gce/gce_discover.go#L23-L43)
+ * Hetzner Cloud [Config options](https://github.com/hashicorp/go-discover/blob/master/provider/hcloud/hcloud_discover.go#L17-L24)
  * Linode [Config options](https://github.com/hashicorp/go-discover/blob/master/provider/linode/linode_discover.go#L30-L41)
  * mDNS [Config options](https://github.com/hashicorp/go-discover/blob/master/provider/mdns/mdns_provider.go#L19-L31)
  * Microsoft Azure [Config options](https://github.com/hashicorp/go-discover/blob/8b3ddf4/provider/azure/azure_discover.go#L24-L62)
@@ -61,6 +62,9 @@ provider=digitalocean region=... tag_name=... api_token=...
 # Google Cloud
 provider=gce project_name=... zone_pattern=eu-west-* tag_value=consul credentials_file=...
 
+# Hetzner Cloud
+provider=hcloud location=... label_selector=... address_type=... api_token=...
+
 # Linode
 provider=linode tag_name=... region=us-east address_type=private_v4 api_token=...
 
@@ -166,7 +170,7 @@ sub-package.
 
 ## Testing
 
-**Note: Due to the `go.sum` checksum errors referenced in [#68](https://github.com/hashicorp/go-discover/issues/68), 
+**Note: Due to the `go.sum` checksum errors referenced in [#68](https://github.com/hashicorp/go-discover/issues/68),
 you will need Go 1.11.4+ to build/test go-discover.**
 
 Configuration tests can be run with Go:

discover.go

@@ -14,6 +14,7 @@ import (
 	"github.com/hashicorp/go-discover/provider/azure"
 	"github.com/hashicorp/go-discover/provider/digitalocean"
 	"github.com/hashicorp/go-discover/provider/gce"
+	"github.com/hashicorp/go-discover/provider/hcloud"
 	"github.com/hashicorp/go-discover/provider/linode"
 	"github.com/hashicorp/go-discover/provider/mdns"
 	"github.com/hashicorp/go-discover/provider/os"
@@ -50,6 +51,7 @@ var Providers = map[string]Provider{
 	"azure":        &azure.Provider{},
 	"digitalocean": &digitalocean.Provider{},
 	"gce":          &gce.Provider{},
+	"hcloud":       &hcloud.Provider{},
 	"linode":       &linode.Provider{},
 	"mdns":         &mdns.Provider{},
 	"os":           &os.Provider{},

go.mod

@@ -11,11 +11,16 @@ require (
 	github.com/hashicorp/go-multierror v1.0.0
 	github.com/hashicorp/mdns v1.0.1
 	github.com/hashicorp/vic v1.5.1-0.20190403131502-bbfe86ec9443
+	github.com/hetznercloud/hcloud-go v1.37.0
+	github.com/imdario/mergo v0.3.6 // indirect
+	github.com/jarcoal/httpmock v0.0.0-20180424175123-9c70cfe4a1da // indirect
 	github.com/joyent/triton-go v0.0.0-20180628001255-830d2b111e62
 	github.com/linode/linodego v0.7.1
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/nicolai86/scaleway-sdk v1.10.2-0.20180628010248-798f60e20bb2
 	github.com/packethost/packngo v0.1.1-0.20180711074735-b9cb5096f54c
+	github.com/renier/xmlrpc v0.0.0-20170708154548-ce4a1a486c03 // indirect
+	github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529 // indirect
 	github.com/softlayer/softlayer-go v0.0.0-20180806151055-260589d94c7d
 	github.com/stretchr/testify v1.7.0
 	github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common v1.0.480

provider/hcloud/hcloud_discover.go

@@ -0,0 +1,129 @@
+// Package hcloud provides node discovery for Hetzner Cloud.
+package hcloud
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+
+	"github.com/hetznercloud/hcloud-go/hcloud"
+)
+
+type Provider struct{}
+
+func (p *Provider) Help() string {
+	return `Hetzner Cloud:
+
+	provider:       "hcloud"
+	location:       The Hetzner Cloud datacenter location to filter by (eg. "fsn1")
+	label_selector: The label selector to filter by
+	address_type:   "private_v4", "public_v4" or "public_v6", defaults to "private_v4". In the case of private networks, the first one will be used
+	api_token:      The Hetzner Cloud API token to use, can also be provided by environment variable: HCLOUD_TOKEN
+`
+}
+
+// serverIP returns the IP address of the specified type for the hcloud server.
+func serverIP(s *hcloud.Server, addrType string, l *log.Logger) string {
+	switch addrType {
+	case "public_v4":
+		if !s.PublicNet.IPv4.Blocked {
+			l.Printf("[INFO] discover-hcloud: instance %s (%d) has public IP %s", s.Name, s.ID, s.PublicNet.IPv4.IP.String())
+			return s.PublicNet.IPv4.IP.String()
+		} else if len(s.PublicNet.FloatingIPs) != 0 {
+			l.Printf("[INFO] discover-hcloud: public IPv4 for instance %s (%d) is blocked, checking associated floating IPs", s.Name, s.ID)
+			for _, floatingIP := range s.PublicNet.FloatingIPs {
+				if floatingIP.Type == hcloud.FloatingIPTypeIPv4 && !floatingIP.Blocked {
+					l.Printf("[INFO] discover-hcloud: instance %s (%d) has floating IP %s", s.Name, s.ID, floatingIP.IP.String())
+					return floatingIP.IP.String()
+				}
+			}
+		}
+	case "public_v6":
+		if !s.PublicNet.IPv6.Blocked {
+			l.Printf("[INFO] discover-hcloud: instance %s (%d) has public IP %s", s.Name, s.ID, s.PublicNet.IPv6.IP.String())
+			return s.PublicNet.IPv6.IP.String()
+		} else if len(s.PublicNet.FloatingIPs) != 0 {
+			l.Printf("[INFO] discover-hcloud: public IPv6 for instance %s (%d) is blocked, checking associated floating IPs", s.Name, s.ID)
+			for _, floatingIP := range s.PublicNet.FloatingIPs {
+				if floatingIP.Type == hcloud.FloatingIPTypeIPv6 && !floatingIP.Blocked {
+					l.Printf("[INFO] discover-hcloud: instance %s (%d) has floating IP %s", s.Name, s.ID, floatingIP.IP.String())
+					return floatingIP.IP.String()
+				}
+			}
+		}
+	case "private_v4":
+		if len(s.PrivateNet) == 0 {
+			l.Printf("[INFO] discover-hcloud: instance %s (%d) has no private IP", s.Name, s.ID)
+		} else {
+			l.Printf("[INFO] discover-hcloud: instance %s (%d) has private IP %s", s.Name, s.ID, s.PrivateNet[0].IP.String())
+			return s.PrivateNet[0].IP.String()
+		}
+	default:
+	}
+
+	l.Printf("[DEBUG] discover-hcloud: instance %s (%d) has no valid associated IP address", s.Name, s.ID)
+	return ""
+}
+
+func (p *Provider) Addrs(args map[string]string, l *log.Logger) ([]string, error) {
+	if args["provider"] != "hcloud" {
+		return nil, fmt.Errorf("discover-hcloud: invalid provider %s", args["provider"])
+	}
+
+	if l == nil {
+		l = log.New(ioutil.Discard, "", 0)
+	}
+
+	labelSelector := args["label_selector"]
+	addrType := args["address_type"]
+	location := args["location"]
+	apiToken := args["api_token"]
+
+	if apiToken == "" {
+		l.Printf("[INFO] no API token specified, checking environment variable HCLOUD_TOKEN")
+		apiToken = os.Getenv("HCLOUD_TOKEN")
+		if apiToken == "" {
+			return nil, fmt.Errorf("discover-hcloud: no api_token specified")
+		}
+	}
+
+	if addrType == "" {
+		l.Printf("[INFO] discover-hcloud: address type not provided, using 'private_v4'")
+		addrType = "private_v4"
+	}
+
+	if addrType != "private_v4" && addrType != "public_v4" && addrType != "public_v6" {
+		l.Printf("[INFO] discover-hcloud: address_type %s is invalid, falling back to 'private_v4'. valid values are: private_v4, public_v4, public_v6", addrType)
+		addrType = "private_v4"
+	}
+
+	l.Printf("[DEBUG] discover-hcloud: using address_type=%s label_selector=%s location=%s", addrType, labelSelector, location)
+
+	client := hcloud.NewClient(hcloud.WithToken(apiToken))
+
+	options := hcloud.ServerListOpts{
+		ListOpts: hcloud.ListOpts{
+			LabelSelector: labelSelector,
+		},
+		Status: []hcloud.ServerStatus{hcloud.ServerStatusRunning},
+	}
+
+	servers, err := client.Server.AllWithOpts(context.Background(), options)
+	if err != nil {
+		return nil, fmt.Errorf("discover-hcloud: %s", err)
+	}
+
+	var addrs []string
+	for _, s := range servers {
+		if location == "" || location == s.Datacenter.Location.Name {
+			if serverIP := serverIP(s, addrType, l); serverIP != "" {
+				addrs = append(addrs, serverIP)
+			}
+		}
+	}
+
+	log.Printf("[DEBUG] discover-hcloud: found IP addresses: %v", addrs)
+	return addrs, nil
+}

provider/hcloud/hcloud_discover_test.go

@@ -0,0 +1,47 @@
+package hcloud_test
+
+import (
+	"log"
+	"os"
+	"testing"
+
+	discover "github.com/hashicorp/go-discover"
+	"github.com/hashicorp/go-discover/provider/hcloud"
+)
+
+var _ discover.Provider = (*hcloud.Provider)(nil)
+var addrTests = map[string]struct {
+	addrType string
+	location string
+	outLen   int
+}{
+	"public ipv4 all locations":    {"public_v4", "", 2},
+	"public ipv6 all locations":    {"public_v6", "", 2},
+	"private ipv4 all locations":   {"private_v4", "", 2},
+	"private ipv4 fsn1 datacenter": {"private_v4", "fsn1", 1},
+	"public ipv6 nbg1 datacenter":  {"public_v6", "nbg1", 1},
+	"public ipv4 hel1 datacenter":  {"public_v4", "hel1", 0},
+}
+
+func TestAddrs(t *testing.T) {
+	l := log.New(os.Stderr, "", log.LstdFlags)
+	for name, at := range addrTests {
+		t.Run(name, func(t *testing.T) {
+			args := discover.Config{
+				"provider":       "hcloud",
+				"label_selector": "go-discover-test-tag",
+				"address_type":   at.addrType,
+			}
+			p := &hcloud.Provider{}
+			addrs, err := p.Addrs(args, l)
+
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if len(addrs) != at.outLen {
+				t.Fatalf("expected: %d, got: %d", at.outLen, len(addrs))
+			}
+		})
+	}
+}

test/tf/hcloud/input.tf

@@ -0,0 +1,19 @@
+variable "prefix" {
+  default = "go-discover"
+}
+
+variable "hcloud_image" {
+  default = "ubuntu-20.04"
+}
+
+variable "hcloud_location_nbg" {
+  default = "nbg1"
+}
+
+variable "hcloud_location_fsn" {
+  default = "fsn1"
+}
+
+variable "hcloud_size" {
+  default = "cx11"
+}

test/tf/hcloud/main.tf

@@ -0,0 +1,46 @@
+provider "hcloud" {
+}
+
+resource "hcloud_server" "test-01" {
+  count       = 2
+  image       = var.hcloud_image
+  name        = "${var.prefix}-01-${count.index + 1}"
+  server_type = var.hcloud_size
+  location    = var.hcloud_location_nbg
+  labels = {
+    "${var.prefix}-test-tag" : ""
+  }
+}
+
+resource "hcloud_server" "test-02" {
+  image       = var.hcloud_image
+  name        = "${var.prefix}-02"
+  server_type = var.hcloud_size
+  location    = var.hcloud_location_fsn
+}
+
+resource "hcloud_network" "internal" {
+  name     = "${var.prefix}-internal"
+  ip_range = "10.0.0.0/8"
+  labels = {
+    "${var.prefix}-test-tag" : ""
+  }
+}
+
+resource "hcloud_network_subnet" "subnet" {
+  network_id   = hcloud_network.internal.id
+  type         = "cloud"
+  network_zone = "eu-central"
+  ip_range     = "10.0.1.0/24"
+}
+
+resource "hcloud_server_network" "test-01" {
+  count     = 2
+  server_id = hcloud_server.test-01[count.index].id
+  subnet_id = hcloud_network_subnet.subnet.id
+}
+
+resource "hcloud_server_network" "test-02" {
+  server_id = hcloud_server.test-02.id
+  subnet_id = hcloud_network_subnet.subnet.id
+}

test/tf/hcloud/versions.tf

@@ -0,0 +1,10 @@
+terraform {
+  required_providers {
+    hcloud = {
+      source  = "hetznercloud/hcloud"
+      version = "1.36.0"
+    }
+  }
+
+  required_version = ">=0.12"
+}