bugfix: fixed wrong zipkin Arguments (#2193)

fix #2191

apisix/plugins/zipkin.lua

@@ -59,7 +59,25 @@ function _M.check_schema(conf)
 end
 
 
-local function create_tracer(conf)
+local function create_tracer(conf,ctx)
+
+    local headers = core.request.headers(ctx)
+
+-- X-B3-Sampled: if an upstream decided to sample this request, we do too.
+    local sample = headers["x-b3-sampled"]
+    if sample == "1" or sample == "true" then
+        conf.sample_ratio = 1
+    elseif sample == "0" or sample == "false" then
+        conf.sample_ratio = 0
+    end
+
+-- X-B3-Flags: if it equals '1' then it overrides sampling policy
+-- We still want to warn on invalid sample header, so do this after the above
+    local debug = headers["x-b3-flags"]
+    if debug == "1" then
+        conf.sample_ratio = 1
+    end
+
     local tracer = new_tracer(new_reporter(conf), new_random_sampler(conf))
     tracer:register_injector("http_headers", zipkin_codec.new_injector())
     tracer:register_extractor("http_headers", zipkin_codec.new_extractor())
@@ -91,7 +109,7 @@ function _M.rewrite(plugin_conf, ctx)
     end
 
     local tracer = core.lrucache.plugin_ctx(plugin_name .. '#' .. conf.server_addr, ctx,
-                                            create_tracer, conf)
+                                            create_tracer, conf, ctx)
 
     ctx.opentracing_sample = tracer.sampler:sample()
     if not ctx.opentracing_sample then

apisix/plugins/zipkin/codec.lua

@@ -35,26 +35,6 @@ end
 
 local function new_extractor()
     return function(headers)
--- X-B3-Sampled: if an upstream decided to sample this request, we do too.
-        local sample = headers["x-b3-sampled"]
-        if sample == "1" or sample == "true" then
-            sample = true
-        elseif sample == "0" or sample == "false" then
-            sample = false
-        elseif sample ~= nil then
-            core.log.warn("x-b3-sampled header invalid; ignoring.")
-            sample = nil
-        end
-
--- X-B3-Flags: if it equals '1' then it overrides sampling policy
--- We still want to warn on invalid sample header, so do this after the above
-        local debug = headers["x-b3-flags"]
-        if debug == "1" then
-            sample = true
-        elseif debug ~= nil then
-            core.log.warn("x-b3-flags header invalid; ignoring.")
-        end
-
         local had_invalid_id = false
 
         local trace_id = headers["x-b3-traceid"]
@@ -99,7 +79,7 @@ local function new_extractor()
         request_span_id = from_hex(request_span_id)
 
         return new_span_context(trace_id, request_span_id, parent_span_id,
-                                 sample, baggage)
+                                 baggage)
     end
 end