feat: allow skipping filters (#63)

Author: spacewander

lib/resty/apisix/response.lua

@@ -13,6 +13,10 @@ typedef intptr_t ngx_int_t;
 ngx_int_t
 ngx_http_apisix_set_gzip(ngx_http_request_t *r, ngx_int_t num, size_t size,
     ngx_int_t level);
+ngx_int_t
+ngx_http_apisix_skip_header_filter_by_lua(ngx_http_request_t *r);
+ngx_int_t
+ngx_http_apisix_skip_body_filter_by_lua(ngx_http_request_t *r);
 ]]
 
 
@@ -33,4 +37,26 @@ function _M.set_gzip(opts)
 end
 
 
+-- The skip_* methods must be called before any output is generated,
+-- so the flag can take effect
+function _M.skip_header_filter_by_lua()
+    local r = get_request()
+    local rc = C.ngx_http_apisix_skip_header_filter_by_lua(r)
+    if rc == NGX_ERROR then
+        return nil, "no memory"
+    end
+    return true
+end
+
+
+function _M.skip_body_filter_by_lua()
+    local r = get_request()
+    local rc = C.ngx_http_apisix_skip_body_filter_by_lua(r)
+    if rc == NGX_ERROR then
+        return nil, "no memory"
+    end
+    return true
+end
+
+
 return _M

patch/1.21.4/ngx_lua-skip_filter.patch

@@ -0,0 +1,54 @@
+diff --git src/ngx_http_lua_bodyfilterby.c src/ngx_http_lua_bodyfilterby.c
+index 9024889..88af761 100644
+--- src/ngx_http_lua_bodyfilterby.c
++++ src/ngx_http_lua_bodyfilterby.c
+@@ -22,6 +22,9 @@
+ #include "ngx_http_lua_misc.h"
+ #include "ngx_http_lua_consts.h"
+ #include "ngx_http_lua_output.h"
++#if (NGX_HTTP_APISIX)
++#include "ngx_http_apisix_module.h"
++#endif
+ 
+ 
+ static void ngx_http_lua_body_filter_by_lua_env(lua_State *L,
+@@ -241,6 +244,12 @@ ngx_http_lua_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
+     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                    "lua body filter for user lua code, uri \"%V\"", &r->uri);
+ 
++#if (NGX_HTTP_APISIX)
++    if (ngx_http_apisix_is_body_filter_by_lua_skipped(r)) {
++        return ngx_http_next_body_filter(r, in);
++    }
++#endif
++
+     llcf = ngx_http_get_module_loc_conf(r, ngx_http_lua_module);
+ 
+     if (llcf->body_filter_handler == NULL || r->header_only) {
+diff --git src/ngx_http_lua_headerfilterby.c src/ngx_http_lua_headerfilterby.c
+index ed0c3a6..5f04992 100644
+--- src/ngx_http_lua_headerfilterby.c
++++ src/ngx_http_lua_headerfilterby.c
+@@ -19,6 +19,9 @@
+ #include "ngx_http_lua_string.h"
+ #include "ngx_http_lua_misc.h"
+ #include "ngx_http_lua_consts.h"
++#if (NGX_HTTP_APISIX)
++#include "ngx_http_apisix_module.h"
++#endif
+ 
+ 
+ static ngx_http_output_header_filter_pt ngx_http_next_header_filter;
+@@ -80,6 +83,12 @@ ngx_http_lua_header_filter_by_chunk(lua_State *L, ngx_http_request_t *r)
+ #endif
+     ngx_http_lua_ctx_t          *ctx;
+ 
++#if (NGX_HTTP_APISIX)
++    if (ngx_http_apisix_is_header_filter_by_lua_skipped(r)) {
++        return NGX_OK;
++    }
++#endif
++
+     ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
+     if (ctx->exited) {
+         old_exit_code = ctx->exit_code;

src/ngx_http_apisix_module.c

@@ -574,3 +574,69 @@ ngx_http_apisix_mark_request_header_set(ngx_http_request_t *r)
 
     ctx->request_header_set = 1;
 }
+
+
+ngx_int_t
+ngx_http_apisix_skip_header_filter_by_lua(ngx_http_request_t *r)
+{
+    ngx_http_apisix_ctx_t          *ctx;
+
+    ctx = ngx_http_apisix_get_module_ctx(r);
+    if (ctx == NULL) {
+        return NGX_ERROR;
+    }
+
+    ctx->header_filter_by_lua_skipped = 1;
+    return NGX_OK;
+}
+
+
+ngx_int_t
+ngx_http_apisix_is_header_filter_by_lua_skipped(ngx_http_request_t *r)
+{
+    ngx_http_apisix_ctx_t          *ctx;
+
+    ctx = ngx_http_apisix_get_module_ctx(r);
+    if (ctx != NULL) {
+        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                       "apisix header_filter_by_lua %p skipped: %d",
+                       ctx, ctx->header_filter_by_lua_skipped);
+
+        return ctx->header_filter_by_lua_skipped;
+    }
+
+    return 0;
+}
+
+
+ngx_int_t
+ngx_http_apisix_skip_body_filter_by_lua(ngx_http_request_t *r)
+{
+    ngx_http_apisix_ctx_t          *ctx;
+
+    ctx = ngx_http_apisix_get_module_ctx(r);
+    if (ctx == NULL) {
+        return NGX_ERROR;
+    }
+
+    ctx->body_filter_by_lua_skipped = 1;
+    return NGX_OK;
+}
+
+
+ngx_int_t
+ngx_http_apisix_is_body_filter_by_lua_skipped(ngx_http_request_t *r)
+{
+    ngx_http_apisix_ctx_t          *ctx;
+
+    ctx = ngx_http_apisix_get_module_ctx(r);
+    if (ctx != NULL) {
+        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                       "apisix body_filter_by_lua %p skipped: %d",
+                       ctx, ctx->body_filter_by_lua_skipped);
+
+        return ctx->body_filter_by_lua_skipped;
+    }
+
+    return 0;
+}

src/ngx_http_apisix_module.h

@@ -30,6 +30,8 @@ typedef struct {
     unsigned             request_buffering:1;
     unsigned             request_buffering_set:1;
     unsigned             request_header_set:1;
+    unsigned             header_filter_by_lua_skipped:1;
+    unsigned             body_filter_by_lua_skipped:1;
 } ngx_http_apisix_ctx_t;
 
 
@@ -50,4 +52,8 @@ ngx_int_t ngx_http_apisix_is_request_buffering(ngx_http_request_t *r, ngx_flag_t
 
 void ngx_http_apisix_mark_request_header_set(ngx_http_request_t *r);
 
+ngx_int_t ngx_http_apisix_is_header_filter_by_lua_skipped(ngx_http_request_t *r);
+ngx_int_t ngx_http_apisix_is_body_filter_by_lua_skipped(ngx_http_request_t *r);
+
+
 #endif /* _NGX_HTTP_APISIX_H_INCLUDED_ */

t/skip_filter.t

@@ -0,0 +1,41 @@
+use t::APISIX_NGINX 'no_plan';
+
+run_tests;
+
+__DATA__
+
+=== TEST 1: skip header_filter_by_lua
+--- config
+    location /t {
+        access_by_lua_block {
+            local resp = require("resty.apisix.response")
+            assert(resp.skip_header_filter_by_lua())
+
+            ngx.header["Test"] = "one"
+            ngx.say("ok")
+        }
+        header_filter_by_lua_block {
+            ngx.header["Test"] = "two"
+        }
+    }
+--- response_headers
+Test: one
+
+
+
+=== TEST 2: skip body_filter_by_lua
+--- config
+    location /t {
+        access_by_lua_block {
+            local resp = require("resty.apisix.response")
+            assert(resp.skip_body_filter_by_lua())
+
+            ngx.say("ok")
+        }
+        body_filter_by_lua_block {
+            ngx.arg[1] = "no"
+            ngx.arg[2] = true
+        }
+    }
+--- response_body
+ok