Fix tsdb code and tests to work on Windows.

Add back Windows CI, we lost it when tsdb was merged into the prometheus
repo. There's many tests failing outside tsdb, so only test tsdb for
now.

Fixes #6513

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

.circleci/config.yml

@@ -4,6 +4,7 @@ version: 2.1
 orbs:
   prometheus: prometheus/prometheus@0.3.0
   go: circleci/go@0.2.0
+  win: circleci/windows@2.3.0
 
 executors:
   # Whenever the Go version is updated here, .promu.yml
@@ -49,6 +50,13 @@ jobs:
         key: v1-npm-deps-{{ checksum "web/ui/react-app/yarn.lock" }}
         paths:
         - web/ui/react-app/node_modules
+  test_windows:
+    executor: win/default
+    working_directory: /go/src/github.com/prometheus/prometheus
+    steps:
+    - checkout
+    # TSDB is where the most risk is Windows wise, so only test there for now.
+    - run: go test ./tsdb/...
   fuzzit_regression:
     executor: fuzzit
     working_directory: /go/src/github.com/prometheus/prometheus
@@ -78,6 +86,10 @@ workflows:
         filters:
           tags:
             only: /.*/
+    - test_windows:
+        filters:
+          tags:
+            only: /.*/
     - fuzzit_regression:
         filters:
           tags:

tsdb/block_test.go

@@ -197,9 +197,11 @@ func TestCorruptedChunk(t *testing.T) {
 				testutil.Equals(t, test.openErr.Error(), err.Error())
 				return
 			}
+			defer func() { testutil.Ok(t, b.Close()) }()
 
 			querier, err := NewBlockQuerier(b, 0, 1)
 			testutil.Ok(t, err)
+			defer func() { testutil.Ok(t, querier.Close()) }()
 			set, err := querier.Select(labels.MustNewMatcher(labels.MatchEqual, "a", "b"))
 			testutil.Ok(t, err)
 

tsdb/db_test.go

@@ -2655,6 +2655,7 @@ func TestChunkWriter_ReadAfterWrite(t *testing.T) {
 			// Check the content of the chunks.
 			r, err := chunks.NewDirReader(tempDir, nil)
 			testutil.Ok(t, err)
+			defer func() { testutil.Ok(t, r.Close()) }()
 
 			for _, chks := range test.chks {
 				for _, chkExp := range chks {
@@ -2705,4 +2706,5 @@ func TestChunkReader_ConcurrentReads(t *testing.T) {
 		}
 		wg.Wait()
 	}
+	testutil.Ok(t, r.Close())
 }

tsdb/index/index.go

@@ -511,11 +511,11 @@ func (w *Writer) finishSymbols() error {
 		return err
 	}
 
-	var err error
-	w.symbolFile, err = fileutil.OpenMmapFile(w.f.name)
+	sf, err := fileutil.OpenMmapFile(w.f.name)
 	if err != nil {
 		return err
 	}
+	w.symbolFile = sf
 	hash := crc32.Checksum(w.symbolFile.Bytes()[w.toc.Symbols+4:hashPos], castagnoliTable)
 	w.buf1.Reset()
 	w.buf1.PutBE32(hash)
@@ -700,7 +700,11 @@ func (w *Writer) writePostingsOffsetTable() error {
 	if err != nil {
 		return err
 	}
-	defer f.Close()
+	defer func() {
+		if f != nil {
+			f.Close()
+		}
+	}()
 	d := encoding.NewDecbufRaw(realByteSlice(f.Bytes()), int(w.fPO.pos))
 	cnt := w.cntPO
 	for d.Err() == nil && cnt > 0 {
@@ -720,6 +724,10 @@ func (w *Writer) writePostingsOffsetTable() error {
 	}
 
 	// Cleanup temporary file.
+	if err := f.Close(); err != nil {
+		return err
+	}
+	f = nil
 	if err := w.fPO.close(); err != nil {
 		return err
 	}
@@ -962,9 +970,9 @@ type labelIndexHashEntry struct {
 }
 
 func (w *Writer) Close() error {
-	if err := w.ensureStage(idxStageDone); err != nil {
-		return err
-	}
+	// Even if this fails, we need to close all the files.
+	ensureErr := w.ensureStage(idxStageDone)
+
 	if w.symbolFile != nil {
 		if err := w.symbolFile.Close(); err != nil {
 			return err
@@ -980,7 +988,10 @@ func (w *Writer) Close() error {
 			return err
 		}
 	}
-	return w.f.close()
+	if err := w.f.close(); err != nil {
+		return err
+	}
+	return ensureErr
 }
 
 // StringTuples provides access to a sorted list of string tuples.

tsdb/index/index_test.go

@@ -280,6 +280,7 @@ func TestPostingsMany(t *testing.T) {
 
 	ir, err := NewFileReader(fn)
 	testutil.Ok(t, err)
+	defer func() { testutil.Ok(t, ir.Close()) }()
 
 	cases := []struct {
 		in []string

tsdb/wal/watcher_test.go

@@ -427,6 +427,7 @@ func TestReadCheckpointMultipleSegments(t *testing.T) {
 					}
 				}
 			}
+			testutil.Ok(t, w.Close())
 
 			// At this point we should have at least 6 segments, lets create a checkpoint dir of the first 5.
 			checkpointDir := dir + "/wal/checkpoint.000004"