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plugin/loadbalance: Improve weights update (#5906)

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Don't lock weights for duration of parsing weight file. Add
missing check to reject zero weight values.

Signed-off-by: Gabor Dozsa <gabor.dozsa@ibm.com>
This commit is contained in:
Gabor Dozsa 2023-02-15 18:43:19 +01:00 • committed by GitHub
parent 156da74ad3
commit 52f1c64e7d
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GPG key ID: 4AEE18F83AFDEB23
2 changed files with 26 additions and 20 deletions
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40
plugin/loadbalance/weighted.go
View file

@ -254,26 +254,26 @@ func (w *weightedRR) updateWeights() error {
scanner := bufio.NewScanner(&buf)
// Parse the weight file contents
err = w.parseWeights(scanner)
domains, err := w.parseWeights(scanner)
if err != nil {
return err
}
// access to weights must be protected
w.mutex.Lock()
w.domains = domains
w.mutex.Unlock()
log.Infof("Successfully reloaded weight file %s", w.fileName)
return nil
}
// Parse the weight file contents
func (w *weightedRR) parseWeights(scanner *bufio.Scanner) error {
// access to weights must be protected
w.mutex.Lock()
defer w.mutex.Unlock()
// Reset domains
w.domains = make(map[string]weights)
func (w *weightedRR) parseWeights(scanner *bufio.Scanner) (map[string]weights, error) {
var dname string
var ws weights
domains := make(map[string]weights)
for scanner.Scan() {
nextLine := strings.TrimSpace(scanner.Text())
if len(nextLine) == 0 || nextLine[0:1] == "#" {
@ -285,7 +285,7 @@ func (w *weightedRR) parseWeights(scanner *bufio.Scanner) error {
case 1:
// (domain) name sanity check
if net.ParseIP(fields[0]) != nil {
return fmt.Errorf("Wrong domain name:\"%s\" in weight file %s. (Maybe a missing weight value?)",
return nil, fmt.Errorf("Wrong domain name:\"%s\" in weight file %s. (Maybe a missing weight value?)",
fields[0], w.fileName)
}
dname = fields[0]
@ -295,35 +295,35 @@ func (w *weightedRR) parseWeights(scanner *bufio.Scanner) error {
dname += "."
}
var ok bool
ws, ok = w.domains[dname]
ws, ok = domains[dname]
if !ok {
ws = make(weights, 0)
w.domains[dname] = ws
domains[dname] = ws
}
case 2:
// IP address and weight value
ip := net.ParseIP(fields[0])
if ip == nil {
return fmt.Errorf("Wrong IP address:\"%s\" in weight file %s", fields[0], w.fileName)
return nil, fmt.Errorf("Wrong IP address:\"%s\" in weight file %s", fields[0], w.fileName)
}
weight, err := strconv.ParseUint(fields[1], 10, 8)
if err != nil {
return fmt.Errorf("Wrong weight value:\"%s\" in weight file %s", fields[1], w.fileName)
if err != nil || weight == 0 {
return nil, fmt.Errorf("Wrong weight value:\"%s\" in weight file %s", fields[1], w.fileName)
}
witem := &weightItem{address: ip, value: uint8(weight)}
if dname == "" {
return fmt.Errorf("Missing domain name in weight file %s", w.fileName)
return nil, fmt.Errorf("Missing domain name in weight file %s", w.fileName)
}
ws = append(ws, witem)
w.domains[dname] = ws
domains[dname] = ws
default:
return fmt.Errorf("Could not parse weight line:\"%s\" in weight file %s", nextLine, w.fileName)
return nil, fmt.Errorf("Could not parse weight line:\"%s\" in weight file %s", nextLine, w.fileName)
}
}
if err := scanner.Err(); err != nil {
return fmt.Errorf("Weight file %s parsing error:%s", w.fileName, err)
return nil, fmt.Errorf("Weight file %s parsing error:%s", w.fileName, err)
}
return nil
return domains, nil
}

6
plugin/loadbalance/weighted_test.go
View file

@ -79,6 +79,11 @@ w1,example.org
192.168.1.14 300
`
const zeroWeightWRR = `
w1,example.org
192.168.1.14 0
`
func TestWeightFileUpdate(t *testing.T) {
tests := []struct {
weightFilContent string
@ -95,6 +100,7 @@ func TestWeightFileUpdate(t *testing.T) {
{missingDomainWRR, true, nil, "Missing domain name"},
{wrongIpWRR, true, nil, "Wrong IP address"},
{wrongWeightWRR, true, nil, "Wrong weight value"},
{zeroWeightWRR, true, nil, "Wrong weight value"},
}
for i, test := range tests {