feat(zipkin): support b3 req header

apisix/plugins/zipkin.lua

@@ -20,6 +20,7 @@ local zipkin_codec = require("apisix.plugins.zipkin.codec")
 local new_random_sampler = require("apisix.plugins.zipkin.random_sampler").new
 local new_reporter = require("apisix.plugins.zipkin.reporter").new
 local ngx = ngx
+local ngx_re = require("ngx.re")
 local pairs = pairs
 local tonumber = tonumber
 
@@ -73,6 +74,27 @@ local function create_tracer(conf,ctx)
     return tracer
 end
 
+
+local function parse_b3(b3)
+    -- See https://github.com/openzipkin/b3-propagation#single-header
+    if b3 == "0" then
+        return nil, nil, nil, "0", nil
+    end
+
+    local pieces, err = ngx_re.split(b3, "-", nil, nil, 4)
+    if not pieces then
+        return err
+    end
+    if not pieces[1] then
+        return "missing trace_id"
+    end
+    if not pieces[2] then
+        return "missing span_id"
+    end
+    return nil, pieces[1], pieces[2], pieces[3], pieces[4]
+end
+
+
 function _M.rewrite(plugin_conf, ctx)
     local conf = core.table.clone(plugin_conf)
     -- once the server started, server_addr and server_port won't change, so we can cache it.
@@ -88,29 +110,58 @@ function _M.rewrite(plugin_conf, ctx)
     local headers = core.request.headers(ctx)
     local per_req_sample_ratio
 
-    -- X-B3-Sampled: if the client decided to sample this request, we do too.
-    local sample = headers["x-b3-sampled"]
-    if sample == "1" or sample == "true" then
-        per_req_sample_ratio = 1
-    elseif sample == "0" or sample == "false" then
-        per_req_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
+    -- We still want to warn on invalid sampled header, so do this after the above
     local debug = headers["x-b3-flags"]
     if debug == "1" then
         per_req_sample_ratio = 1
     end
 
+    local trace_id, request_span_id, sampled, parent_span_id
+    local b3 = headers["b3"]
+    if b3 then
+        -- don't pass b3 header by default
+        core.request.set_header(ctx, "b3", nil)
+
+        local err
+        err, trace_id, request_span_id, sampled, parent_span_id = parse_b3(b3)
+
+        if err then
+            core.log.warn("invalid b3 header: ", b3, ", ignored: ", err)
+            return
+        end
+
+        if sampled == "d" then
+            core.request.set_header(ctx, "x-b3-flags", "1")
+            sampled = "1"
+        end
+    else
+        -- X-B3-Sampled: if the client decided to sample this request, we do too.
+        sampled = headers["x-b3-sampled"]
+        trace_id = headers["x-b3-traceid"]
+        parent_span_id = headers["x-b3-parentspanid"]
+        request_span_id = headers["x-b3-spanid"]
+    end
+
+    if sampled == "1" or sampled == "true" then
+        per_req_sample_ratio = 1
+    elseif sampled == "0" or sampled == "false" then
+        per_req_sample_ratio = 0
+    end
+
     ctx.opentracing_sample = tracer.sampler:sample(per_req_sample_ratio or conf.sample_ratio)
     if not ctx.opentracing_sample then
-        core.request.set_header("x-b3-sampled", "0")
+        core.request.set_header(ctx, "x-b3-sampled", "0")
         return
     end
 
-    local wire_context = tracer:extract("http_headers",
-                                        core.request.headers(ctx))
+    local zipkin_ctx = core.tablepool.fetch("zipkin_ctx", 0, 3)
+    zipkin_ctx.trace_id = trace_id
+    zipkin_ctx.parent_span_id = parent_span_id
+    zipkin_ctx.request_span_id = request_span_id
+    ctx.zipkin = zipkin_ctx
+
+    local wire_context = tracer:extract("http_headers", ctx)
 
     local start_timestamp = ngx.req.start_time()
     local request_span = tracer:start_span("apisix.request", {
@@ -205,6 +256,10 @@ function _M.log(conf, ctx)
     end
 
     opentracing.request_span:finish(log_end_time)
+
+    if ctx.zipkin_ctx then
+        core.tablepool.release("zipkin_ctx", ctx.zipkin_ctx)
+    end
 end
 
 return _M

apisix/plugins/zipkin/codec.lua

@@ -34,12 +34,13 @@ local function from_hex(str)
 end
 
 local function new_extractor()
-    return function(headers)
+    return function(ctx)
         local had_invalid_id = false
 
-        local trace_id = headers["x-b3-traceid"]
-        local parent_span_id = headers["x-b3-parentspanid"]
-        local request_span_id = headers["x-b3-spanid"]
+        local zipkin_ctx = ctx.zipkin
+        local trace_id = zipkin_ctx.trace_id
+        local parent_span_id = zipkin_ctx.parent_span_id
+        local request_span_id = zipkin_ctx.request_span_id
 
         -- Validate trace id
         if trace_id and
@@ -68,13 +69,18 @@ local function new_extractor()
 
         -- Process jaegar baggage header
         local baggage = {}
+        local headers = core.request.headers(ctx)
         for k, v in pairs(headers) do
             local baggage_key = k:match("^uberctx%-(.*)$")
             if baggage_key then
                 baggage[baggage_key] = ngx.unescape_uri(v)
             end
         end
 
+        core.log.info("new span context: trace id: ", trace_id,
+                      ", span id: ", request_span_id,
+                      ", parent span id: ", parent_span_id)
+
         trace_id = from_hex(trace_id)
         parent_span_id = from_hex(parent_span_id)
         request_span_id = from_hex(request_span_id)

t/plugin/zipkin2.t

@@ -0,0 +1,141 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+use t::APISIX 'no_plan';
+
+repeat_each(1);
+no_long_string();
+no_root_location();
+log_level("info");
+
+add_block_preprocessor(sub {
+    my ($block) = @_;
+
+    if (!$block->request) {
+        $block->set_value("request", "GET /echo");
+    }
+
+    if (!$block->no_error_log) {
+        $block->set_value("no_error_log", "[error]\n[alert]");
+    }
+});
+
+run_tests;
+
+__DATA__
+
+=== TEST 1: b3 single header
+--- 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,
+                 [[{
+                        "plugins": {
+                            "zipkin": {
+                                "endpoint": "http://127.0.0.1:9999/mock_zipkin",
+                                "sample_ratio": 1
+                            }
+                        },
+                        "upstream": {
+                            "nodes": {
+                                "127.0.0.1:1980": 1
+                            },
+                            "type": "roundrobin"
+                        },
+                        "uri": "/echo"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+
+
+
+=== TEST 2: sanity
+--- more_headers
+b3: 80f198ee56343ba864fe8b2a57d3eff7-e457b5a2e4d86bd1-1-05e3ac9a4f6e3b90
+--- response_headers
+x-b3-sampled: 1
+--- raw_response_headers_unlike
+b3:
+--- error_log
+new span context: trace id: 80f198ee56343ba864fe8b2a57d3eff7, span id: e457b5a2e4d86bd1, parent span id: 05e3ac9a4f6e3b90
+
+
+
+=== TEST 3: invalid header
+--- more_headers
+b3: 80f198ee56343ba864fe8b2a57d3eff7
+--- response_headers
+x-b3-sampled:
+--- error_log
+invalid b3 header
+
+
+
+=== TEST 4: disable via b3
+--- more_headers
+b3: 80f198ee56343ba864fe8b2a57d3eff7-e457b5a2e4d86bd1-0-05e3ac9a4f6e3b90
+--- response_headers
+x-b3-sampled: 0
+
+
+
+=== TEST 5: disable via b3 (abbr)
+--- more_headers
+b3: 0
+--- response_headers
+x-b3-sampled: 0
+
+
+
+=== TEST 6: debug via b3
+--- more_headers
+b3: 80f198ee56343ba864fe8b2a57d3eff7-e457b5a2e4d86bd1-d-05e3ac9a4f6e3b90
+--- response_headers
+x-b3-sampled: 1
+x-b3-flags: 1
+
+
+
+=== TEST 7: b3 without parent span id
+--- more_headers
+b3: 80f198ee56343ba864fe8b2a57d3eff7-e457b5a2e4d86bd1-d
+--- response_headers
+x-b3-sampled: 1
+x-b3-flags: 1
+--- error_log
+new span context: trace id: 80f198ee56343ba864fe8b2a57d3eff7, span id: e457b5a2e4d86bd1, parent span id: nil
+
+
+
+=== TEST 8: b3 without sampled & parent span id
+--- more_headers
+b3: 80f198ee56343ba864fe8b2a57d3eff7-e457b5a2e4d86bd1
+--- response_headers
+x-b3-sampled: 1
+--- error_log
+new span context: trace id: 80f198ee56343ba864fe8b2a57d3eff7, span id: e457b5a2e4d86bd1, parent span id: nil