Allow custom auth backend mount point

Signed-off-by: Dave Henderson <dhenderson@gmail.com>

README.md

@@ -577,9 +577,13 @@ The special `vault://` URL scheme can be used to retrieve data from [Hashicorp
 Vault](https://vaultproject.io). To use this, you must put the Vault server's
 URL in the `$VAULT_ADDR` environment variable.
 
-Currently, the [`app-id`](https://www.vaultproject.io/docs/auth/app-id.html)
-auth backend is supported, as well as Vault tokens obtained through external
-means.
+This table describes the currently-supported authentication mechanisms and how to use them, in order of precedence:
+
+| auth backend | configuration |
+| ---: |--|
+| [`app-id`](https://www.vaultproject.io/docs/auth/app-id.html) | Environment variables `$VAULT_APP_ID` and `$VAULT_USER_ID` must be set to the appropriate values.<br/> If the backend is mounted to a different location, set `$VAULT_AUTH_APP_ID_MOUNT`. |
+| [`github`](https://www.vaultproject.io/docs/auth/github.html) | Environment variable `$VAULT_AUTH_GITHUB_TOKEN` must be set to an appropriate value.<br/> If the backend is mounted to a different location, set `$VAULT_AUTH_GITHUB_MOUNT`. |
+| [`token`](https://www.vaultproject.io/docs/auth/token.html) | Determined from either the `$VAULT_TOKEN` environment variable, or read from the file `~/.vault-token` |
 
 To use a Vault datasource with a single secret, just use a URL of
 `vault:///secret/mysecret`. Note the 3 `/`s - the host portion of the URL is left

vault/app-id_strategy.go

@@ -14,6 +14,7 @@ import (
 type AppIDAuthStrategy struct {
 	AppID  string `json:"app_id"`
 	UserID string `json:"user_id"`
+	Mount  string `json:"-"`
 	hc     *http.Client
 }
 
@@ -22,8 +23,12 @@ type AppIDAuthStrategy struct {
 func NewAppIDAuthStrategy() *AppIDAuthStrategy {
 	appID := os.Getenv("VAULT_APP_ID")
 	userID := os.Getenv("VAULT_USER_ID")
+	mount := os.Getenv("VAULT_AUTH_APP_ID_MOUNT")
+	if mount == "" {
+		mount = "app-id"
+	}
 	if appID != "" && userID != "" {
-		return &AppIDAuthStrategy{appID, userID, nil}
+		return &AppIDAuthStrategy{appID, userID, mount, nil}
 	}
 	return nil
 }
@@ -54,12 +59,12 @@ func (a *AppIDAuthStrategy) GetToken(addr *url.URL) (string, error) {
 
 	u := &url.URL{}
 	*u = *addr
-	u.Path = "/v1/auth/app-id/login"
+	u.Path = "/v1/auth/" + a.Mount + "/login"
 	res, err := requestAndFollow(a, "POST", u, buf.Bytes())
 	if err != nil {
 		return "", err
 	}
-	response := &AuthResponse{}
+	response := &AppIDAuthResponse{}
 	err = json.NewDecoder(res.Body).Decode(response)
 	res.Body.Close()
 	if err != nil {
@@ -78,11 +83,11 @@ func (a *AppIDAuthStrategy) Revokable() bool {
 }
 
 func (a *AppIDAuthStrategy) String() string {
-	return fmt.Sprintf("app-id: %s, user-id: %s", a.AppID, a.UserID)
+	return fmt.Sprintf("app-id: %s, user-id: %s, mount: %s", a.AppID, a.UserID, a.Mount)
 }
 
-// AuthResponse - the Auth response from /v1/auth/app-id/login
-type AuthResponse struct {
+// AppIDAuthResponse - the Auth response from /v1/auth/app-id/login
+type AppIDAuthResponse struct {
 	Auth struct {
 		ClientToken   string `json:"client_token"`
 		LeaseDuration int64  `json:"lease_duration"`
@@ -95,7 +100,7 @@ type AuthResponse struct {
 	} `json:"auth"`
 }
 
-func (a *AuthResponse) String() string {
+func (a *AppIDAuthResponse) String() string {
 	buf := new(bytes.Buffer)
 	json.NewEncoder(buf).Encode(&a)
 	return string(buf.Bytes())

vault/app-id_strategy_test.go

@@ -1,9 +1,6 @@
 package vault
 
 import (
-	"fmt"
-	"net/http"
-	"net/http/httptest"
 	"net/url"
 	"os"
 	"testing"
@@ -36,7 +33,7 @@ func TestGetToken_AppIDErrorsGivenNetworkError(t *testing.T) {
 
 	vaultURL, _ := url.Parse("http://vault:8200")
 
-	auth := &AppIDAuthStrategy{"foo", "bar", client}
+	auth := &AppIDAuthStrategy{"foo", "bar", "app-id", client}
 	_, err := auth.GetToken(vaultURL)
 	assert.Error(t, err)
 }
@@ -47,7 +44,7 @@ func TestGetToken_AppIDErrorsGivenHTTPErrorStatus(t *testing.T) {
 
 	vaultURL, _ := url.Parse("http://vault:8200")
 
-	auth := &AppIDAuthStrategy{"foo", "bar", client}
+	auth := &AppIDAuthStrategy{"foo", "bar", "app-id", client}
 	_, err := auth.GetToken(vaultURL)
 	assert.Error(t, err)
 }
@@ -58,7 +55,7 @@ func TestGetToken_AppIDErrorsGivenBadJSON(t *testing.T) {
 
 	vaultURL, _ := url.Parse("http://vault:8200")
 
-	auth := &AppIDAuthStrategy{"foo", "bar", client}
+	auth := &AppIDAuthStrategy{"foo", "bar", "app-id", client}
 	_, err := auth.GetToken(vaultURL)
 	assert.Error(t, err)
 }
@@ -69,43 +66,9 @@ func TestGetToken_AppID(t *testing.T) {
 
 	vaultURL, _ := url.Parse("http://vault:8200")
 
-	auth := &AppIDAuthStrategy{"foo", "bar", client}
+	auth := &AppIDAuthStrategy{"foo", "bar", "app-id", client}
 	token, err := auth.GetToken(vaultURL)
 	assert.NoError(t, err)
 
 	assert.Equal(t, "baz", token)
 }
-
-func setupHTTP(code int, mimetype string, body string) (*httptest.Server, *http.Client) {
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", mimetype)
-		w.WriteHeader(code)
-		fmt.Fprintln(w, body)
-	}))
-
-	client := &http.Client{
-		Transport: &http.Transport{
-			Proxy: func(req *http.Request) (*url.URL, error) {
-				return url.Parse(server.URL)
-			},
-		},
-	}
-
-	return server, client
-}
-
-func setupErrorHTTP() (*httptest.Server, *http.Client) {
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		panic("boo")
-	}))
-
-	client := &http.Client{
-		Transport: &http.Transport{
-			Proxy: func(req *http.Request) (*url.URL, error) {
-				return url.Parse(server.URL)
-			},
-		},
-	}
-
-	return server, client
-}

vault/testutils.go

@@ -0,0 +1,42 @@
+package vault
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+)
+
+func setupHTTP(code int, mimetype string, body string) (*httptest.Server, *http.Client) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", mimetype)
+		w.WriteHeader(code)
+		fmt.Fprintln(w, body)
+	}))
+
+	client := &http.Client{
+		Transport: &http.Transport{
+			Proxy: func(req *http.Request) (*url.URL, error) {
+				return url.Parse(server.URL)
+			},
+		},
+	}
+
+	return server, client
+}
+
+func setupErrorHTTP() (*httptest.Server, *http.Client) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		panic("boo")
+	}))
+
+	client := &http.Client{
+		Transport: &http.Transport{
+			Proxy: func(req *http.Request) (*url.URL, error) {
+				return url.Parse(server.URL)
+			},
+		},
+	}
+
+	return server, client
+}