adds an executor backed filesystem

filesystem.go

@@ -1,8 +1,12 @@
 package main
 
 import (
+	"bytes"
 	"io/ioutil"
 	"os"
+	"strings"
+
+	"github.com/tsuru/tsuru/exec"
 
 	"github.com/tsuru/tsuru/fs"
 )
@@ -36,3 +40,44 @@ func (f *localFS) CheckFile(name string) (bool, error) {
 func (f *localFS) RemoveFile(name string) error {
 	return f.Fs.Remove(name)
 }
+
+// executorFS is a filesystem backed by an executor
+type executorFS struct {
+	executor exec.Executor
+}
+
+func (f *executorFS) ReadFile(name string) ([]byte, error) {
+	out := new(bytes.Buffer)
+	errOut := new(bytes.Buffer)
+	opts := exec.ExecuteOptions{
+		Cmd:    "cat",
+		Args:   []string{name},
+		Stdout: out,
+		Stderr: errOut,
+	}
+	if err := f.executor.Execute(opts); err != nil {
+		return nil, err
+	}
+	return out.Bytes(), nil
+}
+
+func (f *executorFS) CheckFile(name string) (bool, error) {
+	opts := exec.ExecuteOptions{
+		Cmd:  "stat",
+		Args: []string{name},
+	}
+	if err := f.executor.Execute(opts); err != nil {
+		if strings.Contains(strings.ToLower(err.Error()), "no such") {
+			return false, nil
+		}
+		return false, err
+	}
+	return true, nil
+}
+
+func (f *executorFS) RemoveFile(name string) error {
+	return f.executor.Execute(exec.ExecuteOptions{
+		Cmd:  "rm",
+		Args: []string{name},
+	})
+}

filesystem_test.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"io/ioutil"
+	"os"
+
+	"github.com/tsuru/tsuru/exec"
+
+	"gopkg.in/check.v1"
+)
+
+type FilesystemSuite struct{}
+
+var _ = check.Suite(&FilesystemSuite{})
+
+func (s *FilesystemSuite) TestExecutorFSReadFile(c *check.C) {
+	tmpFile, err := ioutil.TempFile("", "")
+	c.Assert(err, check.IsNil)
+	defer os.Remove(tmpFile.Name())
+	err = ioutil.WriteFile(tmpFile.Name(), []byte("this is the file content"), 0666)
+	c.Assert(err, check.IsNil)
+	fs := executorFS{executor: &exec.OsExecutor{}}
+	data, err := fs.ReadFile(tmpFile.Name())
+	c.Assert(err, check.IsNil)
+	c.Assert(data, check.DeepEquals, []byte("this is the file content"))
+}
+
+func (s *FilesystemSuite) TestExecutorFSCheckFile(c *check.C) {
+	tmpFile, err := ioutil.TempFile("", "")
+	c.Assert(err, check.IsNil)
+	defer os.Remove(tmpFile.Name())
+	fs := executorFS{executor: &exec.OsExecutor{}}
+	exists, err := fs.CheckFile(tmpFile.Name())
+	c.Assert(err, check.IsNil)
+	c.Assert(exists, check.Equals, true)
+	os.Remove(tmpFile.Name())
+	exists, err = fs.CheckFile(tmpFile.Name())
+	c.Assert(exists, check.Equals, false)
+}
+
+func (s *FilesystemSuite) TestExecutorFSRemoveFile(c *check.C) {
+	tmpFile, err := ioutil.TempFile("", "")
+	c.Assert(err, check.IsNil)
+	defer os.Remove(tmpFile.Name())
+	fs := executorFS{executor: &exec.OsExecutor{}}
+	err = fs.RemoveFile(tmpFile.Name())
+	c.Assert(err, check.IsNil)
+	_, err = os.Stat(tmpFile.Name())
+	c.Assert(os.IsNotExist(err), check.Equals, true)
+}