Do not hijack runner stderr for unified logging

locker · locker · commit 136ade3585d5 · 2024-10-31T10:47:40.000+03:00
This is ugly. Instead, let's redirect logs directly to the pipe created by the OutputBeautifier. No changelog because the feature was added by commit f8a1c10 ("Add logging to unified file"), which hasn't been released yet.
diff --git a/luatest/output_beautifier.lua b/luatest/output_beautifier.lua
@@ -59,31 +59,23 @@ end
 -- @string object.prefix String to prefix each output line with.
 -- @string[opt] object.color Color name for prefix.
 -- @string[opt] object.color_code Color code for prefix.
--- @boolean[opt] object.runner Mark OutputBeautifier object is created for runner process.
 -- @return input object.
 function OutputBeautifier:new(object)
-    checks('table', {prefix = 'string', color = '?string', color_code = '?string', runner = '?boolean'})
+    checks('table', {prefix = 'string', color = '?string', color_code = '?string'})
     return self:from(object)
 end
 
 function OutputBeautifier.mt:initialize()
     self.color_code = self.color_code or
         self.class.COLOR_BY_NAME[self.color] or
         OutputBeautifier:next_color_code()
-    self.pipes = {stderr = ffi_io.create_pipe()}
-    if not self.runner then
-        self.pipes.stdout = ffi_io.create_pipe()
-    end
+    self.pipes = {stdout = ffi_io.create_pipe(), stderr = ffi_io.create_pipe()}
     self.stderr = ''
 end
 
 -- Replace standard output descriptors with pipes.
--- Stdout descriptor of the runner process will not be replaced
--- because it is used for displaying all captured data from other processes.
 function OutputBeautifier.mt:hijack_output()
-    if not self.runner then
-        ffi_io.dup2_io(self.pipes.stdout[1], io.stdout)
-    end
+    ffi_io.dup2_io(self.pipes.stdout[1], io.stdout)
     ffi_io.dup2_io(self.pipes.stderr[1], io.stderr)
 end
 
diff --git a/luatest/runner.lua b/luatest/runner.lua
@@ -72,17 +72,14 @@ function Runner.run(args, options)
             local fh = fio.open(options.log_file, {'O_CREAT', 'O_WRONLY'}, tonumber('640', 8))
             rawset(_G, 'log_file', {fh = fh})
 
-            local output_beautifier = OutputBeautifier:new({prefix = log_prefix, runner = true})
+            local output_beautifier = OutputBeautifier:new({prefix = log_prefix})
             output_beautifier:enable()
-            output_beautifier:hijack_output()
 
             -- `tee` copy logs to file and also to standard output, but we need
             -- process all captured data through the OutputBeatifier object.
-            -- Data will be redirected back to stderr of the current process.
-            -- `/dev/fd/2` is a symlink to `/proc/self/fd`, where `/proc/self` is
-            -- a symlink to `/proc/<PID>`. So `/dev/fd/2` is equal to `/proc/<PID>/fd/2`
-            -- and it means "stderr of the current process".
-            log_cfg = string.format("| tee %s > /dev/fd/2", log_cfg)
+            -- So we redirect stdout to the pipe created by OutputBeautifier.
+            log_cfg = string.format("| tee %s > /dev/fd/%d",
+                                    log_cfg, output_beautifier.pipes.stdout[1])
         end
         -- Logging cannot be initialized without configuring the `box` engine
         -- on a version less than 2.5.1 (see more details at [1]). Otherwise,
