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K8SPG-732 pgbackrest debug logs streamed to stderr/stdout and logged #1126

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Merged
hors merged 3 commits into from
Apr 14, 2025
Merged

K8SPG-732 pgbackrest debug logs streamed to stderr/stdout and logged #1126

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307f4c3
K8SPG-732 pgbackrest debug logs streamed to stderr/stdout
gkech Apr 10, 2025
0f43cb0
defer writer errors and move them to the right place
gkech Apr 10, 2025
6522a66
Merge branch 'main' into K8SPG-732
hors Apr 14, 2025
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79 changes: 57 additions & 22 deletions cmd/pgbackrest/main.go
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Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,6 @@ package main
*/

import (
"bytes"
"context"
"io"
"os"
Expand Down Expand Up @@ -96,18 +95,13 @@ func main() {
cmd := createPGBackRestCommand(cfg)
log.Infof("command to execute is [%s]", strings.Join(cmd, " "))

var output, stderr string
// now run the proper exec command depending on whether or not the config hashes should first
// be compared prior to executing the PGBackRest command
if !cfg.compareHash {
output, stderr, err = runCommand(ctx, k, cfg, cmd)
err = runCommand(ctx, k, cfg, cmd)
} else {
output, stderr, err = compareHashAndRunCommand(ctx, k, cfg, cmd)
err = compareHashAndRunCommand(ctx, k, cfg, cmd)
}

// log any output and check for errors
log.Info("output=[" + output + "]")
log.Info("stderr=[" + stderr + "]")
if err != nil {
log.Fatal(err)
}
Expand All @@ -117,13 +111,11 @@ func main() {

// Exec returns the stdout and stderr from running a command inside an existing
// container.
func (k *KubeAPI) Exec(ctx context.Context, namespace, pod, container string, stdin io.Reader, command []string) (string, string, error) {
var stdout, stderr bytes.Buffer

func (k *KubeAPI) Exec(ctx context.Context, namespace, pod, container string, stdin io.Reader, command []string) error {
Scheme := runtime.NewScheme()
if err := corev1.AddToScheme(Scheme); err != nil {
log.Error(err)
return "", "", err
return err
}
ParameterCodec := runtime.NewParameterCodec(Scheme)

Expand All @@ -140,15 +132,58 @@ func (k *KubeAPI) Exec(ctx context.Context, namespace, pod, container string, st

exec, err := remotecommand.NewSPDYExecutor(k.Config, "POST", request.URL())

if err == nil {
err = exec.StreamWithContext(ctx, remotecommand.StreamOptions{
Stdin: stdin,
Stdout: &stdout,
Stderr: &stderr,
})
}
stdoutReader, stdoutWriter := io.Pipe()
defer func() {
if err := stdoutWriter.Close(); err != nil {
log.Errorf("error closing stdoutWriter: %v", err)
}
}()

stderrReader, stderrWriter := io.Pipe()
defer func() {
if err := stderrWriter.Close(); err != nil {
log.Errorf("error closing stderrWriter: %v", err)
}
}()

go streamUsingPrefix("[pgbackrest:stdout]", stdoutReader)
go streamUsingPrefix("[pgbackrest:stderr]", stderrReader)

err = exec.StreamWithContext(ctx, remotecommand.StreamOptions{
Stdin: stdin,
Stdout: stdoutWriter,
Stderr: stderrWriter,
})

return stdout.String(), stderr.String(), err
return err
}

// streamUsingPrefix reads from an io.Reader line by line and logs each line
// prefixing it with a custom label provided as input.
func streamUsingPrefix(prefix string, reader io.Reader) {
buf := make([]byte, 4096)
line := ""
for {
n, err := reader.Read(buf)
if n > 0 {
line += string(buf[:n])
for strings.Contains(line, "\n") {
idx := strings.Index(line, "\n")
part := line[:idx]
log.Infof("%s %s", prefix, part)
line = line[idx+1:]
}
}
if err != nil {
if err != io.EOF {
log.Errorf("%s error reading: %v", prefix, err)
}
break
}
}
if line != "" {
log.Infof("%s %s", prefix, line)
}
}

func NewConfig() (*rest.Config, error) {
Expand Down Expand Up @@ -313,7 +348,7 @@ func createPGBackRestCommand(cfg config) []string {
// command. Only if the hashes match will the pgBackRest command be run, otherwise and error will
// be written and exit code 1 will be returned. This is done to ensure a pgBackRest command is only
// run when it can be verified that the exepected configuration is present.
func compareHashAndRunCommand(ctx context.Context, kubeapi *KubeAPI, cfg config, cmd []string) (string, string, error) {
func compareHashAndRunCommand(ctx context.Context, kubeapi *KubeAPI, cfg config, cmd []string) error {
// the base script used in both the local and exec commands created below
baseScript := `
shopt -s globstar
Expand Down Expand Up @@ -352,7 +387,7 @@ fi

// runCommand runs the provided pgBackRest command according to the configuration
// provided
func runCommand(ctx context.Context, kubeapi *KubeAPI, cfg config, cmd []string) (string, string, error) {
func runCommand(ctx context.Context, kubeapi *KubeAPI, cfg config, cmd []string) error {
bashCmd := []string{"bash"}
reader := strings.NewReader(strings.Join(cmd, " "))
return kubeapi.Exec(ctx, cfg.namespace, cfg.podName, cfg.container, reader, bashCmd)
Expand Down
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