From b2e94fc73c1c51d1dc8c0f790aba3e9cb355671d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Markus=20M=C3=A4kel=C3=A4?= <markus456@gmail.com>
Date: Tue, 2 May 2017 16:34:41 +0300
Subject: [PATCH] MXS-1220: Add versioned URLs

Added versioning to URLs. This should allow somewhat safe modification to
the API after it has been finished.
---
 server/core/admin.cc                 |  7 ++++-
 server/core/httprequest.cc           | 38 ++++++++++++++++++----------
 server/core/httpresponse.cc          |  5 ++++
 server/core/maxscale/httprequest.hh  | 13 +++++++++-
 server/core/maxscale/httpresponse.hh |  1 +
 5 files changed, 49 insertions(+), 15 deletions(-)

diff --git a/server/core/admin.cc b/server/core/admin.cc
index c54072b85..558b8a0fc 100644
--- a/server/core/admin.cc
+++ b/server/core/admin.cc
@@ -102,7 +102,12 @@ int Client::process(string url, string method, const char* upload_data, size_t *
     }
 
     HttpRequest request(m_connection, url, method, json);
-    HttpResponse reply = resource_handle_request(request);
+    HttpResponse reply(MHD_HTTP_NOT_FOUND);
+
+    if (request.validate_api_version())
+    {
+        reply = resource_handle_request(request);
+    }
 
     string data;
 
diff --git a/server/core/httprequest.cc b/server/core/httprequest.cc
index 12301c0f8..f8580411b 100644
--- a/server/core/httprequest.cc
+++ b/server/core/httprequest.cc
@@ -74,20 +74,12 @@ static void process_uri(string& uri, std::deque<string>& uri_parts)
         my_uri.erase(my_uri.begin());
     }
 
-    if (my_uri.length() == 0)
+    while (my_uri.length() > 0)
     {
-        /** Special handling for the / resource */
-        uri_parts.push_back("");
-    }
-    else
-    {
-        while (my_uri.length() > 0)
-        {
-            size_t pos = my_uri.find("/");
-            string part = pos == string::npos ? my_uri : my_uri.substr(0, pos);
-            my_uri.erase(0, pos == string::npos ? pos : pos + 1);
-            uri_parts.push_back(part);
-        }
+        size_t pos = my_uri.find("/");
+        string part = pos == string::npos ? my_uri : my_uri.substr(0, pos);
+        my_uri.erase(0, pos == string::npos ? pos : pos + 1);
+        uri_parts.push_back(part);
     }
 }
 
@@ -102,9 +94,29 @@ HttpRequest::HttpRequest(struct MHD_Connection *connection, string url, string m
 
     m_hostname = mxs_admin_https_enabled() ? HttpRequest::HTTPS_PREFIX : HttpRequest::HTTP_PREFIX;
     m_hostname += get_header(HTTP_HOST_HEADER);
+
+    if (m_hostname[m_hostname.size() - 1] != '/')
+    {
+        m_hostname += "/";
+    }
+
+    m_hostname += MXS_REST_API_VERSION;
 }
 
 HttpRequest::~HttpRequest()
 {
 
 }
+bool HttpRequest::validate_api_version()
+{
+    bool rval = false;
+
+    if (m_resource_parts.size() > 0 &&
+        m_resource_parts[0] == MXS_REST_API_VERSION)
+    {
+        m_resource_parts.pop_front();
+        rval = true;
+    }
+
+    return rval;
+}
diff --git a/server/core/httpresponse.cc b/server/core/httpresponse.cc
index e0c6e4982..8708d7c11 100644
--- a/server/core/httpresponse.cc
+++ b/server/core/httpresponse.cc
@@ -33,6 +33,11 @@ HttpResponse::HttpResponse(int code, json_t* response):
     add_header(HTTP_RESPONSE_HEADER_LAST_MODIFIED, http_date);
     // This ETag is the base64 encoding of `not-yet-implemented`
     add_header(HTTP_RESPONSE_HEADER_ETAG, "bm90LXlldC1pbXBsZW1lbnRlZAo");
+
+    if (m_body)
+    {
+        add_header(HTTP_RESPONSE_HEADER_CONTENT_TYPE, "application/json");
+    }
 }
 
 HttpResponse::HttpResponse(const HttpResponse& response):
diff --git a/server/core/maxscale/httprequest.hh b/server/core/maxscale/httprequest.hh
index 6986d676a..e99875c3d 100644
--- a/server/core/maxscale/httprequest.hh
+++ b/server/core/maxscale/httprequest.hh
@@ -26,6 +26,9 @@
 
 #include "http.hh"
 
+// The API version part of the URL
+#define MXS_REST_API_VERSION "v1"
+
 static int value_iterator(void *cls,
                           enum MHD_ValueKind kind,
                           const char *key,
@@ -160,6 +163,14 @@ public:
     {
         return m_hostname.c_str();
     }
+
+    /**
+     * @brief Drop the API version prefix
+     *
+     * @return True if prefix is present and was successfully removed
+     */
+    bool validate_api_version();
+
 private:
 
     /** Constants */
@@ -173,5 +184,5 @@ private:
     std::deque<std::string>            m_resource_parts; /**< @c m_resource split into parts */
     std::string                        m_verb;           /**< Request method */
     std::string                        m_hostname;       /**< The value of the Host header */
-    struct MHD_Connection* m_connection;
+    struct MHD_Connection*             m_connection;
 };
diff --git a/server/core/maxscale/httpresponse.hh b/server/core/maxscale/httpresponse.hh
index 3bf96672d..4e5801f45 100644
--- a/server/core/maxscale/httpresponse.hh
+++ b/server/core/maxscale/httpresponse.hh
@@ -30,6 +30,7 @@
 #define HTTP_RESPONSE_HEADER_LAST_MODIFIED "Last-Modified"
 #define HTTP_RESPONSE_HEADER_ETAG          "ETag"
 #define HTTP_RESPONSE_HEADER_ACCEPT        "Accept"
+#define HTTP_RESPONSE_HEADER_CONTENT_TYPE  "Content-Type"
 
 typedef std::map<std::string, std::string> Headers;