test_helpers.go

Documentation: github.com/ory/x/watcherx

     1  package watcherx
     2  
     3  import (
     4  	"io/ioutil"
     5  	"os"
     6  	"path"
     7  	"path/filepath"
     8  	"runtime"
     9  	"testing"
    10  	"time"
    11  
    12  	"github.com/stretchr/testify/require"
    13  )
    14  
    15  func kubernetesAtomicWrite(t *testing.T, dir, fileName, content string) {
    16  	// atomic write according to https://github.com/kubernetes/kubernetes/blob/master/pkg/volume/util/atomic_writer.go
    17  	const (
    18  		dataDirName    = "..data"
    19  		newDataDirName = "..data_tmp"
    20  	)
    21  	// (2)
    22  	dataDirPath := filepath.Join(dir, dataDirName)
    23  	oldTsDir, err := os.Readlink(dataDirPath)
    24  	if err != nil {
    25  		require.True(t, os.IsNotExist(err), "%+v", err)
    26  		// although Readlink() returns "" on err, don't be fragile by relying on it (since it's not specified in docs)
    27  		// empty oldTsDir indicates that it didn't exist
    28  		oldTsDir = ""
    29  	}
    30  	oldTsPath := filepath.Join(dir, oldTsDir)
    31  
    32  	// (3) we are not interested in the case where a file gets deleted as we just operate on one file
    33  	// (4) we assume the file needs an update
    34  
    35  	// (5)
    36  	tsDir, err := ioutil.TempDir(dir, time.Now().UTC().Format("..2006_01_02_15_04_05."))
    37  	require.NoError(t, err)
    38  	tsDirName := filepath.Base(tsDir)
    39  
    40  	// (6)
    41  	require.NoError(
    42  		t,
    43  		ioutil.WriteFile(path.Join(tsDir, fileName), []byte(content), 0600),
    44  	)
    45  
    46  	// (7)
    47  	_, err = os.Readlink(filepath.Join(dir, fileName))
    48  	if err != nil && os.IsNotExist(err) {
    49  		// The link into the data directory for this path doesn't exist; create it
    50  		require.NoError(
    51  			t,
    52  			os.Symlink(filepath.Join(dataDirName, fileName), filepath.Join(dir, fileName)),
    53  		)
    54  	}
    55  
    56  	// (8)
    57  	newDataDirPath := filepath.Join(dir, newDataDirName)
    58  	require.NoError(
    59  		t,
    60  		os.Symlink(tsDirName, newDataDirPath),
    61  	)
    62  
    63  	// (9)
    64  	if runtime.GOOS == "windows" {
    65  		require.NoError(t, os.Remove(dataDirPath))
    66  		require.NoError(t, os.Symlink(tsDirName, dataDirPath))
    67  		require.NoError(t, os.Remove(newDataDirPath))
    68  	} else {
    69  		require.NoError(t, os.Rename(newDataDirPath, dataDirPath))
    70  	}
    71  
    72  	// (10) in our case there is nothing to remove
    73  
    74  	// (11)
    75  	if len(oldTsDir) > 0 {
    76  		require.NoError(t, os.RemoveAll(oldTsPath))
    77  	}
    78  }
    79
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