feat: add OAuth2 support

Resolves #76

Signed-off-by: Romain Beuque <556072+rbeuque74@users.noreply.github.com>

Author: rbeuque74

README.md

@@ -61,6 +61,51 @@ Alternatively it is suggested to use configuration files or environment
 variables so that the same code may run seamlessly in multiple environments.
 Production and development for instance.
 
+`go-ovh` supports two forms of authentication:
+- OAuth2, using scopped service accounts, and compatible with OVHcloud IAM
+- application key & application secret & consumer key
+
+### OAuth2
+
+First, you need to generate a pair of valid `client_id` and `client_secret`: you
+can proceed by [following this documentation](https://help.ovhcloud.com/csm/en-manage-service-account?id=kb_article_view&sysparm_article=KB0059343)
+
+Once you have retrieved your `client_id` and `client_secret`, you can create and edit
+a configuration file that will be used by `go-ovh`.
+
+```ini
+[default]
+; general configuration: default endpoint
+endpoint=ovh-eu
+
+[ovh-eu]
+; configuration specific to 'ovh-eu' endpoint
+client_id=my_client_id
+client_secret=my_client_secret
+```
+
+The client will successively attempt to locate this configuration file in
+
+1. Current working directory: ``./ovh.conf``
+2. Current user's home directory: ``~/.ovh.conf``
+3. System wide configuration: ``/etc/ovh.conf``
+
+Depending on the API you want to use, you may set the ``endpoint`` to:
+
+* ``ovh-eu`` for OVHcloud Europe API
+* ``ovh-us`` for OVHcloud US API
+* ``ovh-ca`` for OVHcloud Canada API
+
+This lookup mechanism makes it easy to overload credentials for a specific
+project or user.
+
+### Application Key/Application Secret
+
+If you have completed successfully the __OAuth2__ part, you can continue to
+[the Use the Lib part](https://github.com/ovh/go-ovh?tab=readme-ov-file#use-the-lib).
+
+This section will cover the legacy authentication method using application key and
+application secret.
 This wrapper will first look for direct instanciation parameters then
 ``OVH_ENDPOINT``, ``OVH_APPLICATION_KEY``, ``OVH_APPLICATION_SECRET`` and
 ``OVH_CONSUMER_KEY`` environment variables. If either of these parameter is not
@@ -98,7 +143,7 @@ The client will successively attempt to locate this configuration file in
 This lookup mechanism makes it easy to overload credentials for a specific
 project or user.
 
-## Register your app
+#### Register your app
 
 OVHcloud's API, like most modern APIs is designed to authenticate both an application and
 a user, without requiring the user to provide a password. Your application will be
@@ -116,7 +161,7 @@ This process is detailed in the following section. Alternatively, you may only n
 to build an application for a single user. In this case you may generate all
 credentials at once. See below.
 
-### Use the API on behalf of a user
+##### Use the API on behalf of a user
 
 Visit [https://eu.api.ovh.com/createApp](https://eu.api.ovh.com/createApp) and create your app
 You'll get an application key and an application secret. To use the API you'll need a consumer key.
@@ -178,7 +223,7 @@ func main() {
 }
 ```
 
-### Use the API for a single user
+##### Use the API for a single user
 
 Alternatively, you may generate all creadentials at once, including the consumer key. You will
 typically want to do this when writing automation scripts for a single projects.
@@ -309,9 +354,10 @@ client.Get("/xdsl/xdsl-yourservice", nil)
 
 ### Create a client
 
-- Use ``ovh.NewClient()`` to have full controll over ther authentication
-- Use ``ovh.NewEndpointClient()`` to create a client for a specific API and use credentials from config files or environment
 - Use ``ovh.NewDefaultClient()`` to create a client unsing endpoint and credentials from config files or environment
+- Use ``ovh.NewEndpointClient()`` to create a client for a specific API and use credentials from config files or environment
+- Use ``ovh.NewOAuth2Client()`` to have full control over their authentication, using OAuth2 authentication method
+- Use ``ovh.NewClient()`` to have full control over their authentication, using legacy authentication method
 
 ### Query
 
@@ -342,6 +388,8 @@ Or, for unauthenticated requests:
 
 ### Request consumer keys
 
+__[Only valid for legacy authentication method]__
+
 Consumer keys may be restricted to a subset of the API. This allows to delegate the API to manage
 only a specific server or domain name for example. This is called "scoping" a consumer key.
 

go.mod

@@ -5,12 +5,17 @@ go 1.18
 require (
 	github.com/jarcoal/httpmock v1.3.0
 	github.com/maxatome/go-testdeep v1.12.0
+	golang.org/x/oauth2 v0.18.0
 	gopkg.in/ini.v1 v1.67.0
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/stretchr/testify v1.8.2 // indirect
+	golang.org/x/net v0.22.0 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/protobuf v1.31.0 // indirect
 )
 
 retract (

go.sum

@@ -1,6 +1,12 @@
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
+github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
+github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/jarcoal/httpmock v1.3.0 h1:2RJ8GP0IIaWwcC9Fp2BmVi8Kog3v2Hn7VXM3fTd+nuc=
 github.com/jarcoal/httpmock v1.3.0/go.mod h1:3yb8rc4BI7TCBhFY8ng0gjuLKJNquuDNiPaZjnENuYg=
 github.com/maxatome/go-testdeep v1.12.0 h1:Ql7Go8Tg0C1D/uMMX59LAoYK7LffeJQ6X2T04nTH68g=
@@ -14,6 +20,23 @@ github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
 github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
+golang.org/x/net v0.22.0 h1:9sGLhx7iRIHEiX0oAJ3MRZMUCElJgy7Br1nO+AMN3Tc=
+golang.org/x/net v0.22.0/go.mod h1:JKghWKKOSdJwpW2GEx0Ja7fmaKnMsbu+MWVZTokSYmg=
+golang.org/x/oauth2 v0.18.0 h1:09qnuIAgzdx1XplqJvW6CQqMCtGZykZWcXzPMPUusvI=
+golang.org/x/oauth2 v0.18.0/go.mod h1:Wf7knwG0MPoWIMMBgFlEaSUDaKskp0dCfrlJRJXbBi8=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/appengine v1.6.7 h1:FZR1q0exgwxzPzp/aF+VccGrSfxfPpkBqjIIEq3ru6c=
+google.golang.org/appengine v1.6.7/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=
+google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
+google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
+google.golang.org/protobuf v1.31.0 h1:g0LDEJHgrBl9N9r17Ru3sqWhkIx2NB67okBHPwC7hs8=
+google.golang.org/protobuf v1.31.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA=
 gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=

ovh/configuration.go

@@ -1,11 +1,14 @@
 package ovh
 
 import (
+	"context"
+	"errors"
 	"fmt"
 	"os"
 	"os/user"
 	"strings"
 
+	"golang.org/x/oauth2/clientcredentials"
 	"gopkg.in/ini.v1"
 )
 
@@ -114,6 +117,27 @@ func (c *Client) loadConfig(endpointName string) error {
 		c.ConsumerKey = getConfigValue(cfg, endpointName, "consumer_key", "")
 	}
 
+	if c.ClientID == "" {
+		c.ClientID = getConfigValue(cfg, endpointName, "client_id", "")
+	}
+
+	if c.ClientSecret == "" {
+		c.ClientSecret = getConfigValue(cfg, endpointName, "client_secret", "")
+	}
+
+	if (c.ClientID != "") != (c.ClientSecret != "") {
+		return errors.New("invalid oauth2 config, both client_id and client_secret must be given")
+	}
+	if (c.AppKey != "") != (c.AppSecret != "") {
+		return errors.New("invalid authentication config, both application_key and application_secret must be given")
+	}
+
+	if c.ClientID != "" && c.AppKey != "" {
+		return errors.New("can't use both application_key/application_secret and OAuth2 client_id/client_secret")
+	} else if c.ClientID == "" && c.AppKey == "" {
+		return errors.New("missing authentication information, you need to provide at least an application_key/application_secret or a client_id/client_secret")
+	}
+
 	// Load real endpoint URL by name. If endpoint contains a '/', consider it as a URL
 	if strings.Contains(endpointName, "/") {
 		c.endpoint = endpointName
@@ -123,13 +147,21 @@ func (c *Client) loadConfig(endpointName string) error {
 
 	// If we still have no valid endpoint, AppKey or AppSecret, return an error
 	if c.endpoint == "" {
-		return fmt.Errorf("unknown endpoint '%s', consider checking 'Endpoints' list of using an URL", endpointName)
+		return fmt.Errorf("unknown endpoint '%s', consider checking 'Endpoints' list or using an URL", endpointName)
 	}
-	if c.AppKey == "" {
-		return fmt.Errorf("missing application key, please check your configuration or consult the documentation to create one")
-	}
-	if c.AppSecret == "" {
-		return fmt.Errorf("missing application secret, please check your configuration or consult the documentation to create one")
+
+	if c.ClientID != "" {
+		if _, ok := tokensURLs[c.endpoint]; !ok {
+			return fmt.Errorf("oauth2 authentication is not compatible with endpoint %q", c.endpoint)
+		}
+
+		conf := &clientcredentials.Config{
+			ClientID:     c.ClientID,
+			ClientSecret: c.ClientSecret,
+			TokenURL:     tokensURLs[c.endpoint],
+		}
+
+		c.oauth2TokenSource = conf.TokenSource(context.Background())
 	}
 
 	return nil

ovh/configuration_test.go

@@ -7,14 +7,18 @@ import (
 )
 
 const (
-	systemConf       = "testdata/system.ini"
-	userPartialConf  = "testdata/userPartial.ini"
-	userConf         = "testdata/user.ini"
-	localPartialConf = "testdata/localPartial.ini"
-	localWithURLConf = "testdata/localWithURL.ini"
-	doesNotExistConf = "testdata/doesNotExist.ini"
-	invalidINIConf   = "testdata/invalid.ini"
-	errorConf        = "testdata"
+	systemConf                   = "testdata/system.ini"
+	userPartialConf              = "testdata/userPartial.ini"
+	userConf                     = "testdata/user.ini"
+	userOAuth2Conf               = "testdata/user_oauth2.ini"
+	userOAuth2InvalidConf        = "testdata/user_oauth2_invalid.ini"
+	userOAuth2IncompatibleConfig = "testdata/user_oauth2_incompatible.ini"
+	userBothConf                 = "testdata/user_both.ini"
+	localPartialConf             = "testdata/localPartial.ini"
+	localWithURLConf             = "testdata/localWithURL.ini"
+	doesNotExistConf             = "testdata/doesNotExist.ini"
+	invalidINIConf               = "testdata/invalid.ini"
+	errorConf                    = "testdata"
 )
 
 func setConfigPaths(t testing.TB, paths ...string) {
@@ -60,7 +64,7 @@ func TestConfigFromNonExistingFile(t *testing.T) {
 
 	client := Client{}
 	err := client.loadConfig("ovh-eu")
-	td.CmpString(t, err, `missing application key, please check your configuration or consult the documentation to create one`)
+	td.CmpString(t, err, `missing authentication information, you need to provide at least an application_key/application_secret or a client_id/client_secret`)
 }
 
 func TestConfigFromInvalidINIFile(t *testing.T) {
@@ -139,16 +143,16 @@ func TestMissingParam(t *testing.T) {
 
 	client.endpoint = ""
 	err := client.loadConfig("")
-	td.CmpString(t, err, `unknown endpoint '', consider checking 'Endpoints' list of using an URL`)
+	td.CmpString(t, err, `unknown endpoint '', consider checking 'Endpoints' list or using an URL`)
 
 	client.AppKey = ""
 	err = client.loadConfig("ovh-eu")
-	td.CmpString(t, err, `missing application key, please check your configuration or consult the documentation to create one`)
+	td.CmpString(t, err, `invalid authentication config, both application_key and application_secret must be given`)
 	client.AppKey = "param"
 
 	client.AppSecret = ""
 	err = client.loadConfig("ovh-eu")
-	td.CmpString(t, err, `missing application secret, please check your configuration or consult the documentation to create one`)
+	td.CmpString(t, err, `invalid authentication config, both application_key and application_secret must be given`)
 }
 
 func TestConfigPaths(t *testing.T) {
@@ -163,3 +167,39 @@ func TestConfigPaths(t *testing.T) {
 		[]interface{}{"", "file", "file.ini", "dir/file.ini", home + "/file.ini", "~typo.ini"},
 	)
 }
+
+func TestConfigOAuth2(t *testing.T) {
+	setConfigPaths(t, userOAuth2Conf)
+
+	client := Client{}
+	err := client.loadConfig("ovh-eu")
+	td.Require(t).CmpNoError(err)
+	td.Cmp(t, client, td.Struct(Client{
+		ClientID:     "foo",
+		ClientSecret: "bar",
+	}))
+}
+
+func TestConfigInvalidBoth(t *testing.T) {
+	setConfigPaths(t, userBothConf)
+
+	client := Client{}
+	err := client.loadConfig("ovh-eu")
+	td.CmpString(t, err, "can't use both application_key/application_secret and OAuth2 client_id/client_secret")
+}
+
+func TestConfigOAuth2Invalid(t *testing.T) {
+	setConfigPaths(t, userOAuth2InvalidConf)
+
+	client := Client{}
+	err := client.loadConfig("ovh-eu")
+	td.CmpString(t, err, "invalid oauth2 config, both client_id and client_secret must be given")
+}
+
+func TestConfigOAuth2Incompatible(t *testing.T) {
+	setConfigPaths(t, userOAuth2IncompatibleConfig)
+
+	client := Client{}
+	err := client.loadConfig("kimsufi-eu")
+	td.CmpString(t, err, `oauth2 authentication is not compatible with endpoint "https://eu.api.kimsufi.com/1.0"`)
+}