Add munger to verify kubectl -f targets, fix docs

cmd/mungedocs/kubectl_dash_f.go

@@ -0,0 +1,116 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 main
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"strings"
+)
+
+// Looks for lines that have kubectl commands with -f flags and files that
+// don't exist.
+func checkKubectlFileTargets(file string, markdown []byte) ([]byte, error) {
+	inside := false
+	lines := splitLines(markdown)
+	errors := []string{}
+	for i := range lines {
+		if strings.HasPrefix(lines[i], "```") {
+			inside = !inside
+		}
+		if inside {
+			if err := lookForKubectl(lines, i); err != nil {
+				errors = append(errors, err.Error())
+			}
+		}
+	}
+	err := error(nil)
+	if len(errors) != 0 {
+		err = fmt.Errorf("%s", strings.Join(errors, "\n"))
+	}
+	return markdown, err
+}
+
+func lookForKubectl(lines []string, lineNum int) error {
+	fields := strings.Fields(lines[lineNum])
+	for i := range fields {
+		if fields[i] == "kubectl" {
+			return gotKubectl(lineNum, fields, i)
+		}
+	}
+	return nil
+}
+
+func gotKubectl(line int, fields []string, fieldNum int) error {
+	for i := fieldNum + 1; i < len(fields); i++ {
+		switch fields[i] {
+		case "create", "update", "replace", "delete":
+			return gotCommand(line, fields, i)
+		}
+	}
+	return nil
+}
+
+func gotCommand(line int, fields []string, fieldNum int) error {
+	for i := fieldNum + 1; i < len(fields); i++ {
+		if strings.HasPrefix(fields[i], "-f") {
+			return gotDashF(line, fields, i)
+		}
+	}
+	return nil
+}
+
+func gotDashF(line int, fields []string, fieldNum int) error {
+	target := ""
+	if fields[fieldNum] == "-f" {
+		if fieldNum+1 == len(fields) {
+			return fmt.Errorf("ran out of fields after '-f'")
+		}
+		target = fields[fieldNum+1]
+	} else {
+		target = fields[fieldNum][2:]
+	}
+	// Turn dirs into file-like names.
+	target = strings.TrimRight(target, "/")
+
+	// Now exclude special-cases
+
+	if target == "-" || target == "FILENAME" {
+		// stdin and "FILENAME" are OK
+		return nil
+	}
+	if strings.HasPrefix(target, "http://") || strings.HasPrefix(target, "https://") {
+		// URLs are ok
+		return nil
+	}
+	if strings.HasPrefix(target, "./") {
+		// Same-dir files are usually created in the same example
+		return nil
+	}
+	if strings.HasPrefix(target, "/") {
+		// Absolute paths tend to be /tmp/* and created in the same example.
+		return nil
+	}
+
+	// If we got here we expect the file to exist.
+	_, err := os.Stat(path.Join(*rootDir, *repoRoot, target))
+	if os.IsNotExist(err) {
+		return fmt.Errorf("%d: target file %q does not exist", line, target)
+	}
+	return err
+}