fix(brotli-plugin): skip brotli compression for upstream compressed r…

…esponse (#10740)
apache · Jan 12, 2024 · 781e8f6 · 781e8f6
1 parent c11782a
commit 781e8f6
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diff --git a/apisix/plugins/brotli.lua b/apisix/plugins/brotli.lua
@@ -163,6 +163,12 @@ function _M.header_filter(conf, ctx)
         return
     end
 
+    local content_encoded = ngx_header["Content-Encoding"]
+    if content_encoded then
+        -- Don't compress if Content-Encoding is present in upstream data
+        return
+    end
+
     local types = conf.types
     local content_type = ngx_header["Content-Type"]
     if not content_type then

diff --git a/docs/en/latest/plugins/brotli.md b/docs/en/latest/plugins/brotli.md
@@ -47,6 +47,12 @@ sudo sh -c "echo /usr/local/brotli/lib >> /etc/ld.so.conf.d/brotli.conf"
 sudo ldconfig
 ```
 
+:::caution
+
+If the upstream is returning a compressed response, then the Brotli plugin won't be able to compress it.
+
+:::
+
 ## Attributes
 
 | Name           | Type                 | Required | Default       | Valid values | Description                                                                             |

diff --git a/t/lib/server.lua b/t/lib/server.lua
@@ -591,4 +591,11 @@ function _M.clickhouse_logger_server()
 end
 
 
+function _M.mock_compressed_upstream_response()
+    local s = "compressed_response"
+    ngx.header['Content-Encoding'] = 'gzip'
+    ngx.say(s)
+end
+
+
 return _M
diff --git a/t/plugin/brotli.t b/t/plugin/brotli.t
@@ -718,3 +718,68 @@ passed
     }
 --- response_body
 ok
+
+
+
+=== TEST 30: mock upstream compressed response
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1',
+                ngx.HTTP_PUT,
+                [[{
+                    "uri": "/mock_compressed_upstream_response",
+                    "upstream": {
+                        "type": "roundrobin",
+                        "nodes": {
+                            "127.0.0.1:1980": 1
+                        }
+                    },
+                    "plugins": {
+                        "brotli": {
+                            "types": "*"
+                        }
+                    }
+            }]]
+            )
+
+        if code >= 300 then
+            ngx.status = code
+        end
+        ngx.say(body)
+    }
+}
+--- response_body
+passed
+
+
+
+=== TEST 31: hit - skip brotli compression of compressed upstream response
+--- config
+    location /t {
+        content_by_lua_block {
+            local http = require "resty.http"
+            local uri = "http://127.0.0.1:" .. ngx.var.server_port
+                        .. "/mock_compressed_upstream_response"
+            local httpc = http.new()
+            local req_body = ("abcdf01234"):rep(1024)
+            local res, err = httpc:request_uri(uri,
+                {method = "POST", headers = {["Accept-Encoding"] = "gzip, br"}, body = req_body})
+            if not res then
+                ngx.say(err)
+                return
+            end
+            if res.headers["Content-Encoding"] == 'gzip' then
+                ngx.say("ok")
+            end
+        }
+    }
+--- request
+GET /t
+--- more_headers
+Accept-Encoding: gzip, br
+Vary: upstream
+Content-Type: text/html
+--- response_body
+ok