Moved system package inputs out to top level (#4406)

plugins/inputs/linux_sysctl_fs/linux_sysctl_fs_test.go

@@ -0,0 +1,41 @@
+package linux_sysctl_fs
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSysctlFSGather(t *testing.T) {
+	td, err := ioutil.TempDir("", "")
+	require.NoError(t, err)
+	defer os.RemoveAll(td)
+
+	require.NoError(t, ioutil.WriteFile(td+"/aio-nr", []byte("100\n"), 0644))
+	require.NoError(t, ioutil.WriteFile(td+"/aio-max-nr", []byte("101\n"), 0644))
+	require.NoError(t, ioutil.WriteFile(td+"/super-nr", []byte("102\n"), 0644))
+	require.NoError(t, ioutil.WriteFile(td+"/super-max", []byte("103\n"), 0644))
+	require.NoError(t, ioutil.WriteFile(td+"/file-nr", []byte("104\t0\t106\n"), 0644))
+	require.NoError(t, ioutil.WriteFile(td+"/inode-state", []byte("107\t108\t109\t0\t0\t0\t0\n"), 0644))
+
+	sfs := &SysctlFS{
+		path: td,
+	}
+	var acc testutil.Accumulator
+	require.NoError(t, sfs.Gather(&acc))
+
+	acc.AssertContainsFields(t, "linux_sysctl_fs", map[string]interface{}{
+		"aio-nr":             uint64(100),
+		"aio-max-nr":         uint64(101),
+		"super-nr":           uint64(102),
+		"super-max":          uint64(103),
+		"file-nr":            uint64(104),
+		"file-max":           uint64(106),
+		"inode-nr":           uint64(107),
+		"inode-free-nr":      uint64(108),
+		"inode-preshrink-nr": uint64(109),
+	})
+}