From 020af2fac278d45e2e72223741f1980f6d929a7d Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Thu, 2 Apr 2015 22:21:33 -0700
Subject: [PATCH] http: help

---
 api/SPEC.md       | 11 +++++++++++
 api/help.go       |  6 ++++++
 http/handler.go   | 23 ++++++++++++++++++++++-
 http/help.go      | 40 ++++++++++++++++++++++++++++++++++++++++
 http/help_test.go | 27 +++++++++++++++++++++++++++
 5 files changed, 106 insertions(+), 1 deletion(-)
 create mode 100644 api/help.go
 create mode 100644 http/help.go
 create mode 100644 http/help_test.go

diff --git a/api/SPEC.md b/api/SPEC.md
index 99949fba0..09dd433d1 100644
--- a/api/SPEC.md
+++ b/api/SPEC.md
@@ -56,6 +56,17 @@ that can be enabled (see
 Authentication is done with the login endpoint. The login endpoint
 returns an access token that is set as the `token` cookie.
 
+## Help
+
+To retrieve the help for any API within Vault, including mounted
+backends, credential providers, etc. then append `?help=1` to any
+URL. If you have valid permission to access the path, then the help text
+will be returned with the following structure:
+
+        {
+            "help": "help text"
+        }
+
 ## Error Response
 
 A common JSON structure is always returned to return errors:
diff --git a/api/help.go b/api/help.go
new file mode 100644
index 000000000..62a101105
--- /dev/null
+++ b/api/help.go
@@ -0,0 +1,6 @@
+package api
+
+// Help reads the help information for the given path.
+func (c *Client) Help(path string) (string, error) {
+	return "", nil
+}
diff --git a/http/handler.go b/http/handler.go
index 746ed6584..ade250ecc 100644
--- a/http/handler.go
+++ b/http/handler.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"strings"
 
 	"github.com/hashicorp/vault/logical"
 	"github.com/hashicorp/vault/vault"
@@ -15,6 +16,7 @@ const AuthCookieName = "token"
 // Handler returns an http.Handler for the API. This can be used on
 // its own to mount the Vault API within another web server.
 func Handler(core *vault.Core) http.Handler {
+	// Create the muxer to handle the actual endpoints
 	mux := http.NewServeMux()
 	mux.Handle("/v1/sys/init", handleSysInit(core))
 	mux.Handle("/v1/sys/seal-status", handleSysSealStatus(core))
@@ -29,7 +31,26 @@ func Handler(core *vault.Core) http.Handler {
 	mux.Handle("/v1/sys/audit", handleSysListAudit(core))
 	mux.Handle("/v1/sys/audit/", handleSysAudit(core))
 	mux.Handle("/v1/", handleLogical(core))
-	return mux
+
+	// Wrap the handler in another handler to trigger all help paths.
+	handler := handleHelpHandler(mux, core)
+
+	return handler
+}
+
+// stripPrefix is a helper to strip a prefix from the path. It will
+// return false from the second return value if it the prefix doesn't exist.
+func stripPrefix(prefix, path string) (string, bool) {
+	if !strings.HasPrefix(path, prefix) {
+		return "", false
+	}
+
+	path = path[len(prefix):]
+	if path == "" {
+		return "", false
+	}
+
+	return path, true
 }
 
 func parseRequest(r *http.Request, out interface{}) error {
diff --git a/http/help.go b/http/help.go
new file mode 100644
index 000000000..b512da5fc
--- /dev/null
+++ b/http/help.go
@@ -0,0 +1,40 @@
+package http
+
+import (
+	"net/http"
+
+	"github.com/hashicorp/vault/logical"
+	"github.com/hashicorp/vault/vault"
+)
+
+func handleHelpHandler(h http.Handler, core *vault.Core) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		// If the help parameter is not blank, then show the help
+		if v := req.URL.Query().Get("help"); v != "" {
+			handleHelp(core, w, req)
+			return
+		}
+
+		h.ServeHTTP(w, req)
+		return
+	})
+}
+
+func handleHelp(core *vault.Core, w http.ResponseWriter, req *http.Request) {
+	path, ok := stripPrefix("/v1/", req.URL.Path)
+	if !ok {
+		respondError(w, http.StatusNotFound, nil)
+		return
+	}
+
+	resp, err := core.HandleRequest(requestAuth(req, &logical.Request{
+		Operation: logical.HelpOperation,
+		Path:      path,
+	}))
+	if err != nil {
+		respondError(w, http.StatusInternalServerError, err)
+		return
+	}
+
+	respondOk(w, resp.Data)
+}
diff --git a/http/help_test.go b/http/help_test.go
new file mode 100644
index 000000000..2f225e4f9
--- /dev/null
+++ b/http/help_test.go
@@ -0,0 +1,27 @@
+package http
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/hashicorp/vault/vault"
+)
+
+func TestHelp(t *testing.T) {
+	core, _, token := vault.TestCoreUnsealed(t)
+	ln, addr := TestServer(t, core)
+	defer ln.Close()
+	TestServerAuth(t, addr, token)
+
+	resp, err := http.Get(addr + "/v1/sys/mounts?help=1")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	var actual map[string]interface{}
+	testResponseStatus(t, resp, 200)
+	testResponseBody(t, resp, &actual)
+	if _, ok := actual["help"]; !ok {
+		t.Fatalf("bad: %#v", actual)
+	}
+}