commit f8ca6d79390b7f7fac5dbb82635dd6384810c668
author Ed Tanous <edtanous@google.com> Tue Jun 28 12:12:03 2022 -0700
committer Ed Tanous <edtanous@google.com> Tue May 30 13:56:15 2023 -0700
tree ff1c55362a74f5a43d1c05d5d3924ab4d255f948
parent 86a5ac983f9715f7b1a0f8dee355906ac648e1d3

Allow async resolver to be optional

This commit adds a meson option to allow selecting which dns resolver
bmcweb uses.  There are use cases, like Open Compute Project Inband
Management Agent, that would require not using dbus, which would require
us to fall back to the asio resolver.  This commit makes the existing
asio resolver constructor, and async_resolve methods match the
equivalents in asio (which we intended to do anyway), then adds a macro
and configure option for being able to select which resolver backend to
rely on.

Tested: Code can now compile without sdbusplus.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I3220214367179f131a60082bdfaf7e725d35c125

http/http_client.hpp

diff --git a/http/http_client.hpp b/http/http_client.hpp
index 2b498b7..7a98b54 100644
--- a/http/http_client.hpp
+++ b/http/http_client.hpp
@@ -146,7 +146,14 @@
 
     // Ascync callables
     std::function<void(bool, uint32_t, Response&)> callback;
-    crow::async_resolve::Resolver resolver;
+
+#ifdef BMCWEB_DBUS_DNS_RESOLVER
+    using Resolver = crow::async_resolve::Resolver;
+#else
+    using Resolver = boost::asio::ip::tcp::resolver;
+#endif
+    Resolver resolver;
+
     boost::asio::ip::tcp::socket conn;
     std::optional<boost::beast::ssl_stream<boost::asio::ip::tcp::socket&>>
         sslConn;
@@ -162,15 +169,14 @@
                          << std::to_string(port)
                          << ", id: " << std::to_string(connId);
 
-        resolver.asyncResolve(host, port,
-                              std::bind_front(&ConnectionInfo::afterResolve,
-                                              this, shared_from_this()));
+        resolver.async_resolve(host, std::to_string(port),
+                               std::bind_front(&ConnectionInfo::afterResolve,
+                                               this, shared_from_this()));
     }
 
-    void afterResolve(
-        const std::shared_ptr<ConnectionInfo>& /*self*/,
-        const boost::beast::error_code& ec,
-        const std::vector<boost::asio::ip::tcp::endpoint>& endpointList)
+    void afterResolve(const std::shared_ptr<ConnectionInfo>& /*self*/,
+                      const boost::system::error_code& ec,
+                      const Resolver::results_type& endpointList)
     {
         if (ec || (endpointList.empty()))
         {
@@ -591,7 +597,7 @@
         unsigned int connIdIn) :
         subId(idIn),
         connPolicy(connPolicyIn), host(destIPIn), port(destPortIn),
-        connId(connIdIn), conn(iocIn), timer(iocIn)
+        connId(connIdIn), resolver(iocIn), conn(iocIn), timer(iocIn)
     {
         if (useSSL)
         {
@@ -833,8 +839,7 @@
   private:
     std::unordered_map<std::string, std::shared_ptr<ConnectionPool>>
         connectionPools;
-    boost::asio::io_context& ioc =
-        crow::connections::systemBus->get_io_context();
+    boost::asio::io_context& ioc;
     std::shared_ptr<ConnectionPolicy> connPolicy;
 
     // Used as a dummy callback by sendData() in order to call
@@ -847,9 +852,12 @@
 
   public:
     HttpClient() = delete;
-    explicit HttpClient(const std::shared_ptr<ConnectionPolicy>& connPolicyIn) :
+    explicit HttpClient(boost::asio::io_context& iocIn,
+                        const std::shared_ptr<ConnectionPolicy>& connPolicyIn) :
+        ioc(iocIn),
         connPolicy(connPolicyIn)
     {}
+
     HttpClient(const HttpClient&) = delete;
     HttpClient& operator=(const HttpClient&) = delete;
     HttpClient(HttpClient&&) = delete;