Add file input plugin and grok parser (#4332)

plugins/inputs/file/file_test.go

@@ -0,0 +1,61 @@
+package file
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/influxdata/telegraf/plugins/parsers"
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestRefreshFilePaths(t *testing.T) {
+	wd, err := os.Getwd()
+	r := File{
+		Files: []string{filepath.Join(wd, "testfiles/**.log")},
+	}
+
+	err = r.refreshFilePaths()
+	require.NoError(t, err)
+	assert.Equal(t, len(r.filenames), 2)
+}
+func TestJSONParserCompile(t *testing.T) {
+	var acc testutil.Accumulator
+	wd, _ := os.Getwd()
+	r := File{
+		Files: []string{filepath.Join(wd, "testfiles/json_a.log")},
+	}
+	parserConfig := parsers.Config{
+		DataFormat: "json",
+		TagKeys:    []string{"parent_ignored_child"},
+	}
+	nParser, err := parsers.NewParser(&parserConfig)
+	r.parser = nParser
+	assert.NoError(t, err)
+
+	r.Gather(&acc)
+	assert.Equal(t, map[string]string{"parent_ignored_child": "hi"}, acc.Metrics[0].Tags)
+	assert.Equal(t, 5, len(acc.Metrics[0].Fields))
+}
+
+func TestGrokParser(t *testing.T) {
+	wd, _ := os.Getwd()
+	var acc testutil.Accumulator
+	r := File{
+		Files: []string{filepath.Join(wd, "testfiles/grok_a.log")},
+	}
+
+	parserConfig := parsers.Config{
+		DataFormat:   "grok",
+		GrokPatterns: []string{"%{COMMON_LOG_FORMAT}"},
+	}
+
+	nParser, err := parsers.NewParser(&parserConfig)
+	r.parser = nParser
+	assert.NoError(t, err)
+
+	err = r.Gather(&acc)
+	assert.Equal(t, 2, len(acc.Metrics))
+}