feat(patches) add the upstream request recreate feature patches by @locao

These will be removed once
openresty/lua-nginx-module#1734 and
openresty/lua-resty-core#302 are merged

Author: dndx

openresty-patches/patches/1.15.8.3/lua-resty-core-0.1.17_03-upstream_recreate_request.patch

@@ -0,0 +1,55 @@
+From daf26ee06cb4e276c96ea7e34a192f04d5fa7a22 Mon Sep 17 00:00:00 2001
+From: Datong Sun <[email protected]>
+Date: Tue, 23 Jun 2020 17:40:20 -0700
+Subject: [PATCH 1/2] feature: add the `balancer.recreate_request` function,
+ which allows user to recreate request buffer in balancer phase.
+
+This allows certain request parameters, such as headers (including
+`Host` header) to be modified between balancer retries.
+---
+ lua-resty-core-0.1.17/lib/ngx/balancer.lua | 25 ++++++++++++++++++++++
+
+diff --git a/lua-resty-core-0.1.17/lib/ngx/balancer.lua b/lua-resty-core-0.1.17/lib/ngx/balancer.lua
+index d584639..2bc16e1 100644
+--- a/lua-resty-core-0.1.17/lib/ngx/balancer.lua
++++ b/lua-resty-core-0.1.17/lib/ngx/balancer.lua
+@@ -38,6 +38,10 @@ if subsystem == 'http' then
+     int ngx_http_lua_ffi_balancer_set_timeouts(ngx_http_request_t *r,
+         long connect_timeout, long send_timeout,
+         long read_timeout, char **err);
++
++    int
++    ngx_http_lua_ffi_balancer_recreate_request(ngx_http_request_t *r,
++        char **err);
+     ]]
+ 
+     ngx_lua_ffi_balancer_set_current_peer =
+@@ -207,4 +211,25 @@ function _M.set_timeouts(connect_timeout, send_timeout, read_timeout)
+ end
+ 
+ 
++if subsystem == 'http' then
++    function _M.recreate_request()
++        local r = get_request()
++        if not r then
++            error("no request found")
++        end
++
++        local rc = C.ngx_http_lua_ffi_balancer_recreate_request(r, errmsg)
++        if rc == FFI_OK then
++            return true
++        end
++
++        if errmsg[0] ~= nil then
++            return nil, ffi_str(errmsg[0])
++        end
++
++        return nil, "failed to recreate the upstream request"
++    end
++end
++
++
+ return _M
+-- 
+2.20.1
+

openresty-patches/patches/1.15.8.3/ngx_lua-0.10.15_04-upstream_recreate_request.patch

@@ -0,0 +1,62 @@
+From 200cf83dbd180bc015e3e1b5b4344abc665d096a Mon Sep 17 00:00:00 2001
+From: Datong Sun <[email protected]>
+Date: Tue, 23 Jun 2020 17:33:09 -0700
+Subject: [PATCH] feature: added the
+ `ngx_http_lua_ffi_balancer_recreate_request` FFI function to allow recreation
+ of request buffer in balancer phase.
+
+---
+ ngx_lua-0.10.15/src/ngx_http_lua_balancer.c | 39 +++++++++++++++++++++++++++++++++++++
+ 1 file changed, 39 insertions(+)
+
+diff --git a/ngx_lua-0.10.15/src/ngx_http_lua_balancer.c b/ngx_lua-0.10.15/src/ngx_http_lua_balancer.c
+index f71a3e00..eff9dc13 100644
+--- a/ngx_lua-0.10.15/src/ngx_http_lua_balancer.c
++++ b/ngx_lua-0.10.15/src/ngx_http_lua_balancer.c
+@@ -753,4 +753,43 @@ ngx_http_lua_ffi_balancer_get_last_failure(ngx_http_request_t *r,
+ }
+ 
+ 
++int
++ngx_http_lua_ffi_balancer_recreate_request(ngx_http_request_t *r,
++    char **err)
++{
++    ngx_http_lua_ctx_t    *ctx;
++    ngx_http_upstream_t   *u;
++
++    if (r == NULL) {
++        *err = "no request found";
++        return NGX_ERROR;
++    }
++
++    u = r->upstream;
++
++    if (u == NULL) {
++        *err = "no upstream found";
++        return NGX_ERROR;
++    }
++
++    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
++    if (ctx == NULL) {
++        *err = "no ctx found";
++        return NGX_ERROR;
++    }
++
++    if ((ctx->context & NGX_HTTP_LUA_CONTEXT_BALANCER) == 0) {
++        *err = "API disabled in the current context";
++        return NGX_ERROR;
++    }
++
++    /* u->create_request can not be NULL since we are in balancer phase */
++    ngx_http_lua_assert(u->create_request != NULL);
++
++    *err = NULL;
++
++    return u->create_request(r);
++}
++
++
+ #endif  /* NGX_LUA_NO_FFI_API */
+-- 
+2.20.1
+