package libpod import ( "context" "fmt" "os" "os/exec" "strings" "github.com/containers/podman/v4/pkg/errorhandling" "github.com/containers/podman/v4/pkg/rootless" "github.com/containers/podman/v4/pkg/systemd" "github.com/sirupsen/logrus" ) // createTimer systemd timers for healthchecks of a container func (c *Container) createTimer() error { if c.disableHealthCheckSystemd() { return nil } podman, err := os.Executable() if err != nil { return fmt.Errorf("failed to get path for podman for a health check timer: %w", err) } var cmd = []string{} if rootless.IsRootless() { cmd = append(cmd, "--user") } path := os.Getenv("PATH") if path != "" { cmd = append(cmd, "--setenv=PATH="+path) } cmd = append(cmd, "--unit", c.ID(), fmt.Sprintf("--on-unit-inactive=%s", c.HealthCheckConfig().Interval.String()), "--timer-property=AccuracySec=1s", podman, "healthcheck", "run", c.ID()) conn, err := systemd.ConnectToDBUS() if err != nil { return fmt.Errorf("unable to get systemd connection to add healthchecks: %w", err) } conn.Close() logrus.Debugf("creating systemd-transient files: %s %s", "systemd-run", cmd) systemdRun := exec.Command("systemd-run", cmd...) if output, err := systemdRun.CombinedOutput(); err != nil { return fmt.Errorf("%s", output) } return nil } // Wait for a message on the channel. Throw an error if the message is not "done". func systemdOpSuccessful(c chan string) error { msg := <-c switch msg { case "done": return nil default: return fmt.Errorf("expected %q but received %q", "done", msg) } } // startTimer starts a systemd timer for the healthchecks func (c *Container) startTimer() error { if c.disableHealthCheckSystemd() { return nil } conn, err := systemd.ConnectToDBUS() if err != nil { return fmt.Errorf("unable to get systemd connection to start healthchecks: %w", err) } defer conn.Close() startFile := fmt.Sprintf("%s.service", c.ID()) startChan := make(chan string) if _, err := conn.RestartUnitContext(context.Background(), startFile, "fail", startChan); err != nil { return err } if err := systemdOpSuccessful(startChan); err != nil { return fmt.Errorf("starting systemd health-check timer %q: %w", startFile, err) } return nil } // removeTransientFiles removes the systemd timer and unit files // for the container func (c *Container) removeTransientFiles(ctx context.Context) error { if c.disableHealthCheckSystemd() { return nil } conn, err := systemd.ConnectToDBUS() if err != nil { return fmt.Errorf("unable to get systemd connection to remove healthchecks: %w", err) } defer conn.Close() // Errors are returned at the very end. Let's make sure to stop and // clean up as much as possible. stopErrors := []error{} // Stop the timer before the service to make sure the timer does not // fire after the service is stopped. timerChan := make(chan string) timerFile := fmt.Sprintf("%s.timer", c.ID()) if _, err := conn.StopUnitContext(ctx, timerFile, "fail", timerChan); err != nil { if !strings.HasSuffix(err.Error(), ".timer not loaded.") { stopErrors = append(stopErrors, fmt.Errorf("removing health-check timer %q: %w", timerFile, err)) } } else if err := systemdOpSuccessful(timerChan); err != nil { stopErrors = append(stopErrors, fmt.Errorf("stopping systemd health-check timer %q: %w", timerFile, err)) } // Reset the service before stopping it to make sure it's being removed // on stop. serviceChan := make(chan string) serviceFile := fmt.Sprintf("%s.service", c.ID()) if err := conn.ResetFailedUnitContext(ctx, serviceFile); err != nil { logrus.Debugf("Failed to reset unit file: %q", err) } if _, err := conn.StopUnitContext(ctx, serviceFile, "fail", serviceChan); err != nil { if !strings.HasSuffix(err.Error(), ".service not loaded.") { stopErrors = append(stopErrors, fmt.Errorf("removing health-check service %q: %w", serviceFile, err)) } } else if err := systemdOpSuccessful(serviceChan); err != nil { stopErrors = append(stopErrors, fmt.Errorf("stopping systemd health-check service %q: %w", serviceFile, err)) } return errorhandling.JoinErrors(stopErrors) }