Install list of charts in parallel with ok status - go

Question

I use the following code which works and installs helm charts.
I got a list of charts and it installs each chart (via loop) and wait (upgradeAction.Wait = true, see below ) that the chart is up and running (using the wait=true flag of the helm) and then install the next one, the problem is that it takes a lot of time to wait that each chart is up-and-running and just then proceed to the next one, Is there a way to install all in parallel and just verify at the end (of all the charts installations) that it works (like how the wait works but for list of charts).
Here is the code:
mpfile, err := ioutil.TempFile(kp, kcp)
if err != nil {
log.Error(err, "error")
}
defer os.Remove(tmpfile.Name())
if _, err := tmpfile.Write(cfg); err != nil {
return err
}
if err := tmpfile.Close(); err != nil {
return err
}
kcfgFilePath := tmpfile.Name()
settings := cli.New()
ac := new(action.Configuration)
clientGetter := genericclioptions.NewConfigFlags(false)
clientGetter.KubeConfig = &kcfgFilePath
for _, chartInstallation := range charts {
chart, err := loader.Load(chartInstallation.Path)
if err != nil {
return err
}
releaseName := releaseName + "-" + chartInstallation.Name
if err := ac.Init(clientGetter, settings.Namespace(), os.Getenv("HELM_DRIVER"), func(format string, v ...interface{}) {
}); err != nil {
return err
}
releasePresent := true
statusAction := action.NewStatus(ac)
status, err := statusAction.Run(releaseName)
if err != nil {
if strings.Contains(err.Error(), driver.ErrReleaseNotFound.Error()) {
releasePresent = false
} else {
return err
}
}
if !releasePresent {
// install chart
installAction := action.NewInstall(ac)
installAction.CreateNamespace = true
installAction.Namespace = chartInstallation.Namespace
installAction.ReleaseName = releaseName
_, err := installAction.Run(chart, nil)
if err != nil {
return err
}
log.Info("chart installed: ", "releaseName", releaseName)
}
if status != nil {
if releasePresent && status.Info.Status.String() == release.StatusFailed.String() {
upgradeAction := action.NewUpgrade(ac)
// HERE IT WAIT FOR THE CHART TO VERIFY THAT EVERYTHING IS UP
upgradeAction.Wait = true
upgradeAction.ReuseValues = false
upgradeAction.Recreate = false
_, err := upgradeAction.Run(releaseName, chart, nil)
if err != nil {
return err
}
}
}
}
If I change it to upgradeAction.Wait = false , It starts to install all the charts without waiting to each one health checks, however not sure how can I verify it at the end of all the charts installations

Answer 1

You could start goroutines for each chart you're installing (wrapping chart install code inside go routines) and then use sync.WaitGroup to wait all goroutines to finish. Something like this:
package main
import (
"fmt"
"os"
"strings"
"sync"
)
func main() {
kcfgFilePath := tmpfile.Name()
settings := cli.New()
ac := new(action.Configuration)
clientGetter := genericclioptions.NewConfigFlags(false)
clientGetter.KubeConfig = &kcfgFilePath
var wg sync.WaitGroup
for _, chartInstallation := range charts {
wg.Add(1)
go installChart(&wg, chartInstallation.Path)
}
fmt.Println("Installing...")
wg.Wait()
fmt.Println("Installed!")
}
func installChart(wg *sync.WaitGroup, chartInstallationPath string) error {
defer wg.Done()
chart, err := loader.Load(chartInstallationPath)
if err != nil {
return err
}
releaseName := releaseName + "-" + chartInstallation.Name
if err := ac.Init(clientGetter, settings.Namespace(), os.Getenv("HELM_DRIVER"), func(format string, v ...interface{}) {
}); err != nil {
return err
}
releasePresent := true
statusAction := action.NewStatus(ac)
status, err := statusAction.Run(releaseName)
if err != nil {
if strings.Contains(err.Error(), driver.ErrReleaseNotFound.Error()) {
releasePresent = false
} else {
return err
}
}
if !releasePresent {
// install chart
installAction := action.NewInstall(ac)
installAction.CreateNamespace = true
installAction.Namespace = chartInstallation.Namespace
installAction.ReleaseName = releaseName
_, err := installAction.Run(chart, nil)
if err != nil {
return err
}
log.Info("chart installed: ", "releaseName", releaseName)
}
if status != nil {
if releasePresent && status.Info.Status.String() == release.StatusFailed.String() {
upgradeAction := action.NewUpgrade(ac)
// HERE IT WAIT FOR THE CHART TO VERIFY THAT EVERYTHING IS UP
upgradeAction.Wait = true
upgradeAction.ReuseValues = false
upgradeAction.Recreate = false
_, err := upgradeAction.Run(releaseName, chart, nil)
if err != nil {
return err
}
}
}
}
Here's a good resource for that: https://goinbigdata.com/golang-wait-for-all-goroutines-to-finish/