我有一个简短的GO应用程序，我构建来修改配置文件，并期望它们覆盖，但他们正在追加，我不知道为什么。我在os.Truncate()之前尝试了file.Sync()，但最终出现了格式错误的文件。我也试图写入tmp文件，但最终会出现索引错误，并认为这不值得尝试。我希望该文件可以打开，读入，修改和覆盖现有内容。它看起来好像文件没有写完？也许是缓冲区？我做错了什么？
应用
package main
import (
"strings"
"bufio"
"fmt"
"regexp"
"flag"
"os"
"io"
"bytes"
)
var (
filename string
)
func isCommentOrBlank(line string) bool {
return strings.HasPrefix(line, "#") || "" == strings.TrimSpace(line)
}
func fileExists(filename string) bool {
if _, err := os.Stat(filename); err == nil {
return true
}
return false
}
func limitLength(s string, length int) string {
if len(s) < length {
return s
}
return s[:length]
}
func padWithSpace(str, pad string, length int) string {
for {
str += pad
if len(str) > length {
return str[0:length]
}
}
}
func ingest(filename string) (err error) {
file, err := os.OpenFile(filename, os.O_RDWR, 0644)
defer file.Close()
if err != nil {
return err
}
reader := bufio.NewReader(file) // Start reading from the file with a reader.
for {
var buffer bytes.Buffer
var l []byte
var isPrefix bool
for {
l, isPrefix, err = reader.ReadLine()
buffer.Write(l)
if !isPrefix {
break
}
}
if err == io.EOF || err != nil {
break
}
line := buffer.String()
pattern := regexp.MustCompile(`^#([^=]+)=(.+)$`)
matches := pattern.FindAllStringSubmatch(line, -1) // matches is [][]string
for _, string := range matches {
n := strings.Replace(strings.TrimSpace(string[1]), "#", "", -1)
v := strings.TrimSpace(string[2])
e := strings.ToLower(strings.Replace(n, ".", "/", -1))
// newline creation for if block
nl := "{{if exists \"/" + e + "\" -}}\n"
nl += padWithSpace(n, " ", 80) + "= {{getv \"/" + e + "\" \"" + v + "\"}}\n"
nl += "{{end -}}\n"
file.WriteString(nl)
}
// dont proccess comments
if (isCommentOrBlank(line)) {
if (!strings.Contains(line, "=")) {
file.WriteString(line + "\n")
}
} else {
a := strings.Split(line, "=")
n := strings.TrimSpace(a[0])
v := strings.TrimSpace(a[1])
e := strings.ToLower(strings.Replace(n, ".", "/", -1))
file.WriteString(padWithSpace(n, " ", 80) + "= {{getv \"/" + e + "\" \"" + v + "\"}}\n")
}
}
file.Sync()
if err != io.EOF {
fmt.Printf(" > Failed!: %v\n", err)
}
return
}
func main() {
flag.StringVar(&filename, "f", "filename", "The file location to be parsed")
flag.Parse()
if !fileExists(filename) {
fmt.Println(" > File does not exist\n")
}
ingest(filename)
}
配置重写
# The file contains the properties for Chaos Monkey.
# see documentation at:
# https://github.com/Netflix/SimianArmy/wiki/Configuration
# let chaos run
simianarmy.chaos.enabled = true
# don't allow chaos to kill (ie dryrun mode)
simianarmy.chaos.leashed = true
# set to "false" for Opt-In behavior, "true" for Opt-Out behavior
simianarmy.chaos.ASG.enabled = false
# uncomment this line to use tunable aggression
#simianarmy.client.chaos.class = com.netflix.simianarmy.tunable.TunablyAggressiveChaosMonkey
# default probability for all ASGs
simianarmy.chaos.ASG.probability = 1.0
# increase or decrease the termination limit
simianarmy.chaos.ASG.maxTerminationsPerDay = 1.0
# Strategies
simianarmy.chaos.shutdowninstance.enabled = true
simianarmy.chaos.blockallnetworktraffic.enabled = false
simianarmy.chaos.burncpu.enabled = false
simianarmy.chaos.killprocesses.enabled = false
simianarmy.chaos.nullroute.enabled = false
simianarmy.chaos.failapi.enabled = false
simianarmy.chaos.faildns.enabled = false
simianarmy.chaos.faildynamodb.enabled = false
simianarmy.chaos.fails3.enabled = false
simianarmy.chaos.networkcorruption.enabled = false
simianarmy.chaos.networklatency.enabled = false
simianarmy.chaos.networkloss.enabled = false
# Force-detaching EBS volumes may cause data loss
simianarmy.chaos.detachvolumes.enabled = false
# FillDisk fills the root disk.
# NOTE: This may incur charges for an EBS root volume. See burnmoney option.
simianarmy.chaos.burnio.enabled = false
# BurnIO causes disk activity on the root disk.
# NOTE: This may incur charges for an EBS root volume. See burnmoney option.
simianarmy.chaos.filldisk.enabled = false
# Where we know the chaos strategy will incur charges, we won't run it unless burnmoney is true.
simianarmy.chaos.burnmoney = false
# enable a specific ASG
# simianarmy.chaos.ASG.<asgName>.enabled = true
# simianarmy.chaos.ASG.<asgName>.probability = 1.0
# increase or decrease the termination limit for a specific ASG
# simianarmy.chaos.ASG.<asgName>.maxTerminationsPerDay = 1.0
# Enroll in mandatory terminations. If a group has not had a
# termination within the windowInDays range then it will terminate
# one instance in the group with a 0.5 probability (at some point in
# the next 2 days an instance should be terminated), then
# do nothing again for windowInDays. This forces "enabled" groups
# that have a probability of 0.0 to have terminations periodically.
simianarmy.chaos.mandatoryTermination.enabled = false
simianarmy.chaos.mandatoryTermination.windowInDays = 32
simianarmy.chaos.mandatoryTermination.defaultProbability = 0.5
# Enable notification for Chaos termination for a specific instance group
# simianarmy.chaos.<groupType>.<groupName>.notification.enabled = true
# Set the destination email the termination notification sent to for a specific instance group
# simianarmy.chaos.<groupType>.<groupName>.ownerEmail = foo@bar.com
# Set the source email that sends the termination notification
# simianarmy.chaos.notification.sourceEmail = foo@bar.com
# Enable notification for Chaos termination for all instance groups
#simianarmy.chaos.notification.global.enabled = true
# Set the destination email the termination notification is sent to for all instance groups
#simianarmy.chaos.notification.global.receiverEmail = foo@bar.com
# Set a prefix applied to the subject of all termination notifications
# Probably want to include a trailing space to separate from start of default text
#simianarmy.chaos.notification.subject.prefix = SubjectPrefix
# Set a suffix applied to the subject of all termination notifications
# Probably want to include an escaped space " \ " to separate from end of default text
#simianarmy.chaos.notification.subject.suffix = \ SubjectSuffix
# Set a prefix applied to the body of all termination notifications
# Probably want to include a trailing space to separate from start of default text
#simianarmy.chaos.notification.body.prefix = BodyPrefix
# Set a suffix applied to the body of all termination notifications
# Probably want to include an escaped space " \ " to separate from end of default text
#simianarmy.chaos.notification.body.suffix = \ BodySuffix
# Enable the email subject to be the same as the body, to include terminated instance and group information
#simianarmy.chaos.notification.subject.isBody = true
#set the tag filter on the ASGs to terminate only instances from the ASG with the this tag key and value
#simianarmy.chaos.ASGtag.key = chaos_monkey
#simianarmy.chaos.ASGtag.value = true
实际输出
# The file contains the properties for Chaos Monkey.
# see documentation at:
# https://github.com/Netflix/SimianArmy/wiki/Configuration
# let chaos run
simianarmy.chaos.enabled = true
# don't allow chaos to kill (ie dryrun mode)
simianarmy.chaos.leashed = true
# set to "false" for Opt-In behavior, "true" for Opt-Out behavior
simianarmy.chaos.ASG.enabled = false
# uncomment this line to use tunable aggression
#simianarmy.client.chaos.class = com.netflix.simianarmy.tunable.TunablyAggressiveChaosMonkey
# default probability for all ASGs
simianarmy.chaos.ASG.probability = 1.0
# increase or decrease the termination limit
simianarmy.chaos.ASG.maxTerminationsPerDay = 1.0
# Strategies
simianarmy.chaos.shutdowninstance.enabled = true
simianarmy.chaos.blockallnetworktraffic.enabled = false
simianarmy.chaos.burncpu.enabled = false
simianarmy.chaos.killprocesses.enabled = false
simianarmy.chaos.nullroute.enabled = false
simianarmy.chaos.failapi.enabled = false
simianarmy.chaos.faildns.enabled = false
simianarmy.chaos.faildynamodb.enabled = false
simianarmy.chaos.fails3.enabled = false
simianarmy.chaos.networkcorruption.enabled = false
simianarmy.chaos.networklatency.enabled = false
simianarmy.chaos.networkloss.enabled = false
# Force-detaching EBS volumes may cause data loss
simianarmy.chaos.detachvolumes.enabled = false
# FillDisk fills the root disk.
# NOTE: This may incur charges for an EBS root volume. See burnmoney option.
simianarmy.chaos.burnio.enabled = false
# BurnIO causes disk activity on the root disk.
# NOTE: This may incur charges for an EBS root volume. See burnmoney option.
simianarmy.chaos.filldisk.enabled = false
# Where we know the chaos strategy will incur charges, we won't run it unless burnmoney is true.
simianarmy.chaos.burnmoney = false
# enable a specific ASG
# simianarmy.chaos.ASG.<asgName>.enabled = true
# simianarmy.chaos.ASG.<asgName>.probability = 1.0
# increase or decrease the termination limit for a specific ASG
# simianarmy.chaos.ASG.<asgName>.maxTerminationsPerDay = 1.0
# Enroll in mandatory terminations. If a group has not had a
# termination within the windowInDays range then it will terminate
# one instance in the group with a 0.5 probability (at some point in
# the next 2 days an instance should be terminated), then
# do nothing again for windowInDays. This forces "enabled" groups
# that have a probability of 0.0 to have terminations periodically.
simianarmy.chaos.mandatoryTermination.enabled = false
simianarmy.chaos.mandatoryTermination.windowInDays = 32
simianarmy.chaos.mandatoryTermination.defaultProbability = 0.5
# Enable notification for Chaos termination for a specific instance group
# simianarmy.chaos.<groupType>.<groupName>.notification.enabled = true
# Set the destination email the termination notification sent to for a specific instance group
# simianarmy.chaos.<groupType>.<groupName>.ownerEmail = foo@bar.com
# Set the source email that sends the termination notification
# simianarmy.chaos.notification.sourceEmail = foo@bar.com
# Enable notification for Chaos termination for all instance groups
#simianarmy.chaos.notification.global.enabled = true
# Set the destination email the termination notification is sent to for all instance groups
#simianarmy.chaos.notification.global.receiverEmail = foo@bar.com
# Set a prefix applied to the subject of all termination notifications
# Probably want to include a trailing space to separate from start of default text
#simianarmy.chaos.notification.subject.prefix = SubjectPrefix
# Set a suffix applied to the subject of all termination notifications
# Probably want to include an escaped space " \ " to separate from end of default text
#simianarmy.chaos.notification.subject.suffix = \ SubjectSuffix
# Set a prefix applied to the body of all termination notifications
# Probably want to include a trailing space to separate from start of default text
#simianarmy.chaos.notification.body.prefix = BodyPrefix
# Set a suffix applied to the body of all termination notifications
# Probably want to include an escaped space " \ " to separa# The file contains the properties for Chaos Monkey.
# see documentation at:
# https://github.com/Netflix/SimianArmy/wiki/Configuration
# let chaos run
simianarmy.chaos.enabled = {{getv "/simianarmy/chaos/enabled" "true"}}
# don't allow chaos to kill (ie dryrun mode)
simianarmy.chaos.leashed = {{getv "/simianarmy/chaos/leashed" "true"}}
# set to "false" for Opt-In behavior, "true" for Opt-Out behavior
simianarmy.chaos.ASG.enabled = {{getv "/simianarmy/chaos/asg/enabled" "false"}}
# uncomment this line to use tunable aggression
{{if exists "/simianarmy/client/chaos/class" -}}
simianarmy.client.chaos.class = {{getv "/simianarmy/client/chaos/class" "com.netflix.simianarmy.tunable.TunablyAggressiveChaosMonkey"}}
{{end -}}
# default probability for all ASGs
simianarmy.chaos.ASG.probability = {{getv "/simianarmy/chaos/asg/probability" "1.0"}}
# increase or decrease the termination limit
simianarmy.chaos.ASG.maxTerminationsPerDay = {{getv "/simianarmy/chaos/asg/maxterminationsperday" "1.0"}}
# Strategies
simianarmy.chaos.shutdowninstance.enabled = {{getv "/simianarmy/chaos/shutdowninstance/enabled" "true"}}
simianarmy.chaos.blockallnetworktraffic.enabled = {{getv "/simianarmy/chaos/blockallnetworktraffic/enabled" "false"}}
simianarmy.chaos.burncpu.enabled = {{getv "/simianarmy/chaos/burncpu/enabled" "false"}}
simianarmy.chaos.killprocesses.enabled = {{getv "/simianarmy/chaos/killprocesses/enabled" "false"}}
simianarmy.chaos.nullroute.enabled = {{getv "/simianarmy/chaos/nullroute/enabled" "false"}}
simianarmy.chaos.failapi.enabled = {{getv "/simianarmy/chaos/failapi/enabled" "false"}}
simianarmy.chaos.faildns.enabled = {{getv "/simianarmy/chaos/faildns/enabled" "false"}}
simianarmy.chaos.faildynamodb.enabled = {{getv "/simianarmy/chaos/faildynamodb/enabled" "false"}}
simianarmy.chaos.fails3.enabled = {{getv "/simianarmy/chaos/fails3/enabled" "false"}}
simianarmy.chaos.networkcorruption.enabled = {{getv "/simianarmy/chaos/networkcorruption/enabled" "false"}}
simianarmy.chaos.networklatency.enabled = {{getv "/simianarmy/chaos/networklatency/enabled" "false"}}
simianarmy.chaos.networkloss.enabled = {{getv "/simianarmy/chaos/networkloss/enabled" "false"}}
# Force-detaching EBS volumes may cause data loss
simianarmy.chaos.detachvolumes.enabled = {{getv "/simianarmy/chaos/detachvolumes/enabled" "false"}}
# FillDisk fills the root disk.
# NOTE: This may incur charges for an EBS root volume. See burnmoney option.
simianarmy.chaos.burnio.enabled = {{getv "/simianarmy/chaos/burnio/enabled" "false"}}
# BurnIO causes disk activity on the root disk.
# NOTE: This may incur charges for an EBS root volume. See burnmoney option.
simianarmy.chaos.filldisk.enabled = {{getv "/simianarmy/chaos/filldisk/enabled" "false"}}
# Where we know the chaos strategy will incur charges, we won't run it unless burnmoney is true.
simianarmy.chaos.burnmoney = {{getv "/simianarmy/chaos/burnmoney" "false"}}
# enable a specific ASG
{{if exists "/simianarmy/chaos/asg/<asgname>/enabled" -}}
simianarmy.chaos.ASG.<asgName>.enabled = {{getv "/simianarmy/chaos/asg/<asgname>/enabled" "true"}}
{{end -}}
{{if exists "/simianarmy/chaos/asg/<asgname>/probability" -}}
simianarmy.chaos.ASG.<asgName>.probability = {{getv "/simianarmy/chaos/asg/<asgname>/probability" "1.0"}}
{{end -}}
# increase or decrease the termination limit for a specific ASG
{{if exists "/simianarmy/chaos/asg/<asgname>/maxterminationsperday" -}}
simianarmy.chaos.ASG.<asgName>.maxTerminationsPerDay = {{getv "/simianarmy/chaos/asg/<asgname>/maxterminationsperday" "1.0"}}
{{end -}}
# Enroll in mandatory terminations. If a group has not had a
# termination within the windowInDays range then it will terminate
# one instance in the group with a 0.5 probability (at some point in
# the next 2 days an instance should be terminated), then
# do nothing again for windowInDays. This forces "enabled" groups
# that have a probability of 0.0 to have terminations periodically.
simianarmy.chaos.mandatoryTermination.enabled = {{getv "/simianarmy/chaos/mandatorytermination/enabled" "false"}}
simianarmy.chaos.mandatoryTermination.windowInDays = {{getv "/simianarmy/chaos/mandatorytermination/windowindays" "32"}}
simianarmy.chaos.mandatoryTermination.defaultProbability = {{getv "/simianarmy/chaos/mandatorytermination/defaultprobability" "0.5"}}
# Enable notification for Chaos termination for a specific instance group
{{if exists "/simianarmy/chaos/<grouptype>/<groupname>/notification/enabled" -}}
simianarmy.chaos.<groupType>.<groupName>.notification.enabled = {{getv "/simianarmy/chaos/<grouptype>/<groupname>/notification/enabled" "true"}}
{{end -}}
# Set the destination email the termination notification sent to for a specific instance group
{{if exists "/simianarmy/chaos/<grouptype>/<groupname>/owneremail" -}}
simianarmy.chaos.<groupType>.<groupName>.ownerEmail = {{getv "/simianarmy/chaos/<grouptype>/<groupname>/owneremail" "foo@bar.com"}}
{{end -}}
# Set the source email that sends the termination notification
{{if exists "/simianarmy/chaos/notification/sourceemail" -}}
simianarmy.chaos.notification.sourceEmail = {{getv "/simianarmy/chaos/notification/sourceemail" "foo@bar.com"}}
{{end -}}
# Enable notification for Chaos termination for all instance groups
{{if exists "/simianarmy/chaos/notification/global/enabled" -}}
simianarmy.chaos.notification.global.enabled = {{getv "/simianarmy/chaos/notification/global/enabled" "true"}}
{{end -}}
# Set the destination email the termination notification is sent to for all instance groups
{{if exists "/simianarmy/chaos/notification/global/receiveremail" -}}
simianarmy.chaos.notification.global.receiverEmail = {{getv "/simianarmy/chaos/notification/global/receiveremail" "foo@bar.com"}}
{{end -}}
# Set a prefix applied to the subject of all termination notifications
# Probably want to include a trailing space to separate from start of default text
{{if exists "/simianarmy/chaos/notification/subject/prefix" -}}
simianarmy.chaos.notification.subject.prefix = {{getv "/simianarmy/chaos/notification/subject/prefix" "SubjectPrefix"}}
{{end -}}
# Set a suffix applied to the subject of all termination notifications
# Probably want to include an escaped space " \ " to separate from end of default text
{{if exists "/simianarmy/chaos/notification/subject/suffix" -}}
simianarmy.chaos.notification.subject.suffix = {{getv "/simianarmy/chaos/notification/subject/suffix" "\ SubjectSuffix"}}
{{end -}}
# Set a prefix applied to the body of all termination notifications
# Probably want to include a trailing space to separate from start of default text
{{if exists "/simianarmy/chaos/notification/body/prefix" -}}
simianarmy.chaos.notification.body.prefix = {{getv "/simianarmy/chaos/notification/body/prefix" "BodyPrefix"}}
{{end -}}
# Set a suffix applied to the body of all termination notifications
# Probably want to include an escaped space " \ " to separa
答案 0 :(得分：1)
它附加数据，因为当您完成阅读时光标位于文件的末尾。您可以使用Seek()移动光标，或者只需阅读更多内容（os.Open()），然后在完成阅读后覆盖（os.Create()）。