[GitHub] [trafficcontrol] jrushford commented on a change in pull request #4872: traffic_ops_ort.pl transliteration to go

[GitBox <gi...@apache.org>]

jrushford commented on a change in pull request #4872:
URL: https://github.com/apache/trafficcontrol/pull/4872#discussion_r455189915



##########
File path: traffic_ops_ort/traffic_ops_t3c/util/util.go
##########
@@ -0,0 +1,383 @@
+package util
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"github.com/apache/trafficcontrol/lib/go-log"
+	"github.com/apache/trafficcontrol/traffic_ops_ort/traffic_ops_t3c/config"
+	"github.com/gofrs/flock"
+	"io/ioutil"
+	"math/rand"
+	"os"
+	"os/exec"
+	"os/user"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+const OneWeek = 604800
+
+type FileLock struct {
+	f_lock    *flock.Flock
+	is_locked bool
+}
+
+// Try to get a file lock, non-blocking.
+func (f *FileLock) GetLock(lockFile string) bool {
+	f.f_lock = flock.New(lockFile)
+	is_locked, err := f.f_lock.TryLock()
+	f.is_locked = is_locked
+
+	if err != nil { // some OS error attempting to obtain a file lock
+		log.Errorf("unable to obtain a lock on %s\n", lockFile)
+		return false
+	}
+	if !f.is_locked { // another process is running.
+		log.Errorf("Another traffic_ops_t3c process is already running, try again later\n")
+		return false
+	}
+
+	return f.is_locked
+}
+
+// Releases a file lock and exits with the given status code.
+func (f *FileLock) UnlockAndExit(code int) {
+	if f.is_locked {
+		f.f_lock.Unlock()
+	}
+	os.Exit(code)
+}
+
+func DirectoryExists(dir string) (bool, os.FileInfo) {
+	info, err := os.Stat(dir)
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return info.IsDir(), info
+}
+
+func ExecCommand(fullCommand string, arg ...string) ([]byte, int, error) {
+	var output bytes.Buffer
+	cmd := exec.Command(fullCommand, arg...)
+	cmd.Stdout = &output
+	err := cmd.Run()
+	return output.Bytes(), cmd.ProcessState.ExitCode(), err
+}
+
+func FileExists(fn string) (bool, os.FileInfo) {
+	info, err := os.Stat(fn)
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return !info.IsDir(), info
+}
+
+func ReadFile(fn string) ([]byte, error) {
+	var data []byte
+	info, err := os.Stat(fn)
+	if err != nil {
+		return nil, err
+	}
+	size := info.Size()
+
+	fd, err := os.Open(fn)
+	if err != nil {
+		return nil, err
+	}
+	data = make([]byte, size)
+	c, err := fd.Read(data)
+	if err != nil || int64(c) != size {
+		return nil, errors.New("unable to completely read from '" + fn + "': " + err.Error())
+	}
+	fd.Close()
+
+	return data, nil
+}
+
+func serviceStatus(name string) (int, error) {
+	var pid int = -1
+	var result bool
+
+	// the service command returns an error and return code of '3'
+	// if a service is loaded and not running.  So if rc == 3, ignore
+	// the error
+	output, rc, err := ExecCommand("/usr/sbin/service", name, "status")
+	if err != nil && rc != 3 {
+		return pid, errors.New("could not get status for service '" + name + "'\n")
+	}
+	lines := strings.Split(string(output), "\n")
+	for ii := range lines {
+		line := strings.TrimSpace(lines[ii])
+		if strings.Contains(line, "Active: active") {
+			result = true
+		}
+		if result && strings.Contains(line, "Main PID: ") {
+			fmt.Sscanf(line, "Main PID: %d", &pid)
+		}
+	}
+
+	return pid, nil
+}
+
+// start or restart the service 'service'. cmd is 'start | restart'
+func ServiceStart(service string, cmd string) (bool, error) {
+	log.Infof("ServiceStart called for '%s'\n", service)
+	pid, err := serviceStatus(service)
+	if err != nil {
+		return false, errors.New("Could not get status for '" + service + "' : " + err.Error())
+	} else if pid > 0 && cmd == "start" {
+		log.Infof("service '%s' is already running, pid: %d\n", service, pid)
+	} else {
+		_, rc, err := ExecCommand("/usr/sbin/service", service, cmd)
+		if err != nil {
+			return false, errors.New("Could not " + cmd + " the '" + service + "' service: " + err.Error())
+		} else if rc == 0 {
+			// service was sucessfully started
+			return true, nil
+		}
+	}
+	// not started, service is already running
+	return false, nil
+}
+
+func WriteFile(fn string, data []byte, perm os.FileMode) (int, error) {
+	return WriteFileWithOwner(fn, data, -1, -1, perm)
+}
+
+func WriteFileWithOwner(fn string, data []byte, uid int, gid int, perm os.FileMode) (int, error) {
+	fd, err := os.OpenFile(fn, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		return 0, errors.New("unable to open '" + fn + "' for writing: " + err.Error())
+	}
+
+	c, err := fd.Write(data)
+	if err != nil {
+		return 0, errors.New("error writing to '" + fn + "': " + err.Error())
+	}
+	fd.Close()
+
+	if uid > -1 && gid > -1 {
+		err = os.Chown(fn, uid, gid)
+		if err != nil {
+			return 0, errors.New("error changing ownership on '" + fn + "': " + err.Error())
+		}
+	}
+	return c, nil
+}
+
+func PackageAction(cmdstr string, name string) (bool, error) {
+	var rc int = -1
+	var err error = nil
+	var result bool = false
+
+	switch cmdstr {
+	case "info":
+		_, rc, err = ExecCommand("/usr/bin/yum", "info", name)
+	case "install":
+		_, rc, err = ExecCommand("/usr/bin/yum", "install", "-y", name)
+	case "remove":
+		_, rc, err = ExecCommand("/usr/bin/yum", "remove", "-y", name)
+	}
+
+	if rc == 0 {
+		result = true
+		err = nil
+	}
+	return result, err
+}
+
+// runs the rpm command.
+// if the return code from rpm == 0, then a valid package list is returned.
+//
+// if the return code is 1, the the 'name' queried for is not part of a
+//   package or is not installed.
+//
+// otherwise, if the return code is not 0 or 1 and error is set, a general
+// rpm command execution error is assumed and the error is returned.
+func PackageInfo(cmdstr string, name string) ([]string, error) {
+	var result []string
+	switch cmdstr {
+	case "cfg-files": // returns a list of the package configuration files.
+		output, rc, err := ExecCommand("/bin/rpm", "-q", "-c", name)
+		if rc == 1 { // rpm package for 'name' was not found.
+			return nil, nil
+		} else if rc == 0 { // add the package name the file belongs to.
+			log.Debugf("output from cfg-files query: %s\n", string(output))
+			files := strings.Split(string(output), "\n")
+			for ii := range files {
+				result = append(result, strings.TrimSpace(files[ii]))
+			}
+			log.Debugf("result length: %d, result: %s\n", len(result), string(output))
+		} else if err != nil {
+			return nil, err
+		}
+	case "file-query": // returns the rpm name that owns the file 'name'
+		output, rc, err := ExecCommand("/bin/rpm", "-q", "-f", name)
+		if rc == 1 { // file is not part of any package.
+			return nil, nil
+		} else if rc == 0 { // add the package name the file belongs to.
+			log.Debugf("output from file-query: %s\n", string(output))
+			result = append(result, string(strings.TrimSpace(string(output))))
+			log.Debugf("result length: %d, result: %s\n", len(result), string(output))
+		} else if err != nil {
+			return nil, err
+		}
+	case "pkg-provides": // returns the package name that provides 'name'
+		output, rc, err := ExecCommand("/bin/rpm", "-q", "--whatprovides", name)
+		log.Debugf("pkg-provides - name: %s, output: %s\n", name, output)
+		if rc == 1 { // no package provides 'name'
+			return nil, nil
+		} else if rc == 0 {
+			pkgs := strings.Split(string(output), "\n")
+			for ii := range pkgs {
+				result = append(result, strings.TrimSpace(pkgs[ii]))
+			}
+		} else if err != nil {
+			return nil, err
+		}
+	case "pkg-query": // returns the package name for 'name'.
+		output, rc, err := ExecCommand("/bin/rpm", "-q", name)
+		if rc == 1 { // the package is not installed.
+			return nil, nil
+		} else if rc == 0 { // add the rpm name
+			result = append(result, string(strings.TrimSpace(string(output))))
+		} else if err != nil {
+			return nil, err
+		}
+	case "pkg-requires": // returns a list of packages that requires package 'name'
+		output, rc, err := ExecCommand("/bin/rpm", "-q", "--whatrequires", name)
+		if rc == 1 { // no package reuires package 'name'
+			return nil, nil
+		} else if rc == 0 {
+			pkgs := strings.Split(string(output), "\n")
+			for ii := range pkgs {
+				result = append(result, strings.TrimSpace(pkgs[ii]))
+			}
+		} else if err != nil {
+			return nil, err
+		}
+	}
+	return result, nil
+}
+
+func RandomDuration(max time.Duration) time.Duration {
+	rand.Seed(time.Now().UnixNano())
+	return time.Duration(rand.Int63n(int64(max)))

Review comment:
       I've fixed this.  Had a math issue




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