Cleanup code

Signed-off-by: Shiming Zhang <wzshiming@foxmail.com>

pkg/process/io.go

@@ -252,14 +252,6 @@ func NewBinaryIO(ctx context.Context, id string, uri *url.URL) (_ runc.IO, err e
 		return nil, err
 	}
 
-	var args []string
-	for k, vs := range uri.Query() {
-		args = append(args, k)
-		if len(vs) > 0 {
-			args = append(args, vs[0])
-		}
-	}
-
 	var closers []func() error
 	defer func() {
 		if err == nil {
@@ -290,12 +282,7 @@ func NewBinaryIO(ctx context.Context, id string, uri *url.URL) (_ runc.IO, err e
 	}
 	closers = append(closers, r.Close, w.Close)
 
-	cmd := exec.Command(uri.Path, args...)
-	cmd.Env = append(cmd.Env,
-		"CONTAINER_ID="+id,
-		"CONTAINER_NAMESPACE="+ns,
-	)
-
+	cmd := NewBinaryCmd(uri, id, ns)
 	cmd.ExtraFiles = append(cmd.ExtraFiles, out.r, serr.r, w)
 	// don't need to register this with the reaper or wait when
 	// running inside a shim

pkg/process/io_util.go

@@ -0,0 +1,53 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package process
+
+import (
+	"net/url"
+	"os"
+	"os/exec"
+)
+
+// NewBinaryCmd returns a Cmd to be used to start a logging binary.
+// The Cmd is generated from the provided uri, and the container ID and
+// namespace are appended to the Cmd environment.
+func NewBinaryCmd(binaryURI *url.URL, id, ns string) *exec.Cmd {
+	var args []string
+	for k, vs := range binaryURI.Query() {
+		args = append(args, k)
+		if len(vs) > 0 {
+			args = append(args, vs[0])
+		}
+	}
+
+	cmd := exec.Command(binaryURI.Path, args...)
+
+	cmd.Env = append(cmd.Env,
+		"CONTAINER_ID="+id,
+		"CONTAINER_NAMESPACE="+ns,
+	)
+
+	return cmd
+}
+
+// CloseFiles closes any files passed in.
+// It it used for cleanup in the event of unexpected errors.
+func CloseFiles(files ...*os.File) {
+	for _, file := range files {
+		file.Close()
+	}
+}