Files
gluetun/internal/publicip/loop.go
2020-07-16 01:12:54 +00:00

153 lines
3.4 KiB
Go

package publicip
import (
"context"
"sync"
"time"
"github.com/qdm12/golibs/files"
"github.com/qdm12/golibs/logging"
"github.com/qdm12/golibs/network"
"github.com/qdm12/private-internet-access-docker/internal/models"
)
type Looper interface {
Run(ctx context.Context)
RunRestartTicker(ctx context.Context)
Restart()
Stop()
GetPeriod() (period time.Duration)
SetPeriod(period time.Duration)
}
type looper struct {
period time.Duration
periodMutex sync.RWMutex
getter IPGetter
logger logging.Logger
fileManager files.FileManager
ipStatusFilepath models.Filepath
uid int
gid int
restart chan struct{}
stop chan struct{}
updateTimer chan struct{}
tickerReady bool
tickerReadyMutex sync.Mutex
}
func NewLooper(client network.Client, logger logging.Logger, fileManager files.FileManager,
ipStatusFilepath models.Filepath, period time.Duration, uid, gid int) Looper {
return &looper{
period: period,
getter: NewIPGetter(client),
logger: logger.WithPrefix("ip getter: "),
fileManager: fileManager,
ipStatusFilepath: ipStatusFilepath,
uid: uid,
gid: gid,
restart: make(chan struct{}),
stop: make(chan struct{}),
updateTimer: make(chan struct{}),
}
}
func (l *looper) Restart() { l.restart <- struct{}{} }
func (l *looper) Stop() { l.stop <- struct{}{} }
func (l *looper) GetPeriod() (period time.Duration) {
l.periodMutex.RLock()
defer l.periodMutex.RUnlock()
return l.period
}
func (l *looper) SetPeriod(period time.Duration) {
l.tickerReadyMutex.Lock()
defer l.tickerReadyMutex.Unlock()
if !l.tickerReady {
l.logger.Error("cannot set period before ticker is started!")
return
}
l.periodMutex.Lock()
defer l.periodMutex.Unlock()
l.period = period
l.updateTimer <- struct{}{}
}
func (l *looper) logAndWait(ctx context.Context, err error) {
l.logger.Error(err)
l.logger.Info("retrying in 5 seconds")
ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
defer cancel() // just for the linter
<-ctx.Done()
}
func (l *looper) Run(ctx context.Context) {
select {
case <-l.restart:
case <-ctx.Done():
return
}
defer l.logger.Warn("loop exited")
enabled := true
for ctx.Err() == nil {
for !enabled {
// wait for a signal to re-enable
select {
case <-l.stop:
l.logger.Info("already disabled")
case <-l.restart:
enabled = true
case <-ctx.Done():
return
}
}
// Enabled and has a period set
ip, err := l.getter.Get()
if err != nil {
l.logAndWait(ctx, err)
continue
}
l.logger.Info("Public IP address is %s", ip)
err = l.fileManager.WriteLinesToFile(
string(l.ipStatusFilepath),
[]string{ip.String()},
files.Ownership(l.uid, l.gid),
files.Permissions(0600))
if err != nil {
l.logAndWait(ctx, err)
continue
}
select {
case <-l.restart: // triggered restart
case <-l.stop:
enabled = false
case <-ctx.Done():
return
}
}
}
func (l *looper) RunRestartTicker(ctx context.Context) {
l.tickerReadyMutex.Lock()
l.tickerReady = true
l.tickerReadyMutex.Unlock()
ticker := time.NewTicker(l.GetPeriod())
for {
select {
case <-ctx.Done():
ticker.Stop()
return
case <-ticker.C:
l.restart <- struct{}{}
case <-l.updateTimer:
ticker.Stop()
ticker = time.NewTicker(l.GetPeriod())
}
}
}