mirror of
https://github.com/gotenberg/gotenberg.git
synced 2026-08-17 20:52:14 +01:00
process load balancing: broken but in progress
This commit is contained in:
Julien Neuhart
265
internal/pkg/print/chrome.go
Normal file
265
internal/pkg/print/chrome.go
Normal file
@@ -0,0 +1,265 @@
|
||||
package print
|
||||
|
||||
import (
|
||||
"context"
|
||||
"fmt"
|
||||
"io/ioutil"
|
||||
"time"
|
||||
|
||||
"github.com/mafredri/cdp"
|
||||
"github.com/mafredri/cdp/devtool"
|
||||
"github.com/mafredri/cdp/protocol/network"
|
||||
"github.com/mafredri/cdp/protocol/page"
|
||||
"github.com/mafredri/cdp/protocol/target"
|
||||
"github.com/mafredri/cdp/rpcc"
|
||||
"github.com/thecodingmachine/gotenberg/internal/pkg/process"
|
||||
"github.com/thecodingmachine/gotenberg/internal/pkg/xerrgroup"
|
||||
"github.com/thecodingmachine/gotenberg/internal/pkg/xerror"
|
||||
"github.com/thecodingmachine/gotenberg/internal/pkg/xlog"
|
||||
"github.com/thecodingmachine/gotenberg/internal/pkg/xtime"
|
||||
)
|
||||
|
||||
type chromePrint struct {
|
||||
logger xlog.Logger
|
||||
url string
|
||||
opts ChromePrintOptions
|
||||
}
|
||||
|
||||
// ChromePrintOptions helps customizing the
|
||||
// Google Chrome Print result.
|
||||
type ChromePrintOptions struct {
|
||||
WaitDelay float64
|
||||
HeaderHTML string
|
||||
FooterHTML string
|
||||
PaperWidth float64
|
||||
PaperHeight float64
|
||||
MarginTop float64
|
||||
MarginBottom float64
|
||||
MarginLeft float64
|
||||
MarginRight float64
|
||||
Landscape bool
|
||||
}
|
||||
|
||||
// DefaultChromePrintOptions returns the default
|
||||
// Google Chrome Print options.
|
||||
func DefaultChromePrintOptions() ChromePrintOptions {
|
||||
const defaultHeaderFooterHTML string = "<html><head></head><body></body></html>"
|
||||
return ChromePrintOptions{
|
||||
WaitDelay: 0.0,
|
||||
HeaderHTML: defaultHeaderFooterHTML,
|
||||
FooterHTML: defaultHeaderFooterHTML,
|
||||
PaperWidth: 8.27,
|
||||
PaperHeight: 11.7,
|
||||
MarginTop: 1.0,
|
||||
MarginBottom: 1.0,
|
||||
MarginLeft: 1.0,
|
||||
MarginRight: 1.0,
|
||||
Landscape: false,
|
||||
}
|
||||
}
|
||||
|
||||
func (p chromePrint) Print(ctx context.Context, dest string, proc process.Process) error {
|
||||
const op string = "print.chromePrint.Print"
|
||||
resolver := func() error {
|
||||
devtEndpoint := fmt.Sprintf("http://%s:%d", proc.Host(), proc.Port())
|
||||
devt, err := devtool.New(devtEndpoint).Version(ctx)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
// connect to WebSocket URL (page) that speaks the Chrome DevTools Protocol.
|
||||
devtConn, err := rpcc.DialContext(ctx, devt.WebSocketDebuggerURL)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
defer devtConn.Close() // nolint: errcheck
|
||||
// create a new CDP Client that uses conn.
|
||||
devtClient := cdp.NewClient(devtConn)
|
||||
newContextTarget, err := devtClient.Target.CreateBrowserContext(ctx)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
/*
|
||||
close the browser context when done.
|
||||
we're not using the "default" context
|
||||
as it may timeout before actually closing
|
||||
the browser context.
|
||||
see: https://github.com/mafredri/cdp/issues/101#issuecomment-524533670
|
||||
*/
|
||||
disposeBrowserContextArgs := target.NewDisposeBrowserContextArgs(newContextTarget.BrowserContextID)
|
||||
defer devtClient.Target.DisposeBrowserContext(context.Background(), disposeBrowserContextArgs) // nolint: errcheck
|
||||
// create a new blank target with the new browser context.
|
||||
createTargetArgs := target.
|
||||
NewCreateTargetArgs("about:blank").
|
||||
SetBrowserContextID(newContextTarget.BrowserContextID)
|
||||
newTarget, err := devtClient.Target.CreateTarget(ctx, createTargetArgs)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
// connect the client to the new target.
|
||||
newTargetWsURL := fmt.Sprintf("ws://%s:%d/devtools/page/%s", proc.Host(), proc.Port(), newTarget.TargetID)
|
||||
newContextConn, err := rpcc.DialContext(ctx, newTargetWsURL)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
defer newContextConn.Close() // nolint: errcheck
|
||||
// create a new CDP Client that uses newContextConn.
|
||||
targetClient := cdp.NewClient(newContextConn)
|
||||
/*
|
||||
close the target when done.
|
||||
we're not using the "default" context
|
||||
as it may timeout before actually closing
|
||||
the target.
|
||||
see: https://github.com/mafredri/cdp/issues/101#issuecomment-524533670
|
||||
*/
|
||||
closeTargetArgs := target.NewCloseTargetArgs(newTarget.TargetID)
|
||||
defer targetClient.Target.CloseTarget(context.Background(), closeTargetArgs) // nolint: errcheck
|
||||
// enable all events.
|
||||
if err := p.enableEvents(ctx, targetClient); err != nil {
|
||||
return err
|
||||
}
|
||||
// listen for all events.
|
||||
if err := p.listenEvents(ctx, targetClient); err != nil {
|
||||
return err
|
||||
}
|
||||
// apply a wait delay (if any).
|
||||
if p.opts.WaitDelay > 0.0 {
|
||||
// wait for a given amount of time (useful for javascript delay).
|
||||
p.logger.DebugfOp(op, "applying a wait delay of '%.2fs'...", p.opts.WaitDelay)
|
||||
time.Sleep(xtime.Duration(p.opts.WaitDelay))
|
||||
} else {
|
||||
p.logger.DebugOp(op, "no wait delay to apply, moving on...")
|
||||
}
|
||||
// print the page to PDF.
|
||||
print, err := targetClient.Page.PrintToPDF(
|
||||
ctx,
|
||||
page.NewPrintToPDFArgs().
|
||||
SetPaperWidth(p.opts.PaperWidth).
|
||||
SetPaperHeight(p.opts.PaperHeight).
|
||||
SetMarginTop(p.opts.MarginTop).
|
||||
SetMarginBottom(p.opts.MarginBottom).
|
||||
SetMarginLeft(p.opts.MarginLeft).
|
||||
SetMarginRight(p.opts.MarginRight).
|
||||
SetLandscape(p.opts.Landscape).
|
||||
SetDisplayHeaderFooter(true).
|
||||
SetHeaderTemplate(p.opts.HeaderHTML).
|
||||
SetFooterTemplate(p.opts.FooterHTML).
|
||||
SetPrintBackground(true),
|
||||
)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if err := ioutil.WriteFile(dest, print.Data, 0644); err != nil {
|
||||
return err
|
||||
}
|
||||
return nil
|
||||
}
|
||||
if err := resolver(); err != nil {
|
||||
return xerror.New(op, err)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
func (p chromePrint) enableEvents(ctx context.Context, client *cdp.Client) error {
|
||||
const op string = "print.chromePrint.enableEvents"
|
||||
// enable all the domain events that we're interested in.
|
||||
if err := xerrgroup.Run(
|
||||
func() error { return client.DOM.Enable(ctx) },
|
||||
func() error { return client.Network.Enable(ctx, network.NewEnableArgs()) },
|
||||
func() error { return client.Page.Enable(ctx) },
|
||||
func() error {
|
||||
return client.Page.SetLifecycleEventsEnabled(ctx, page.NewSetLifecycleEventsEnabledArgs(true))
|
||||
},
|
||||
func() error { return client.Runtime.Enable(ctx) },
|
||||
); err != nil {
|
||||
return xerror.New(op, err)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
func (p chromePrint) listenEvents(ctx context.Context, client *cdp.Client) error {
|
||||
const op string = "print.chromePrint.listenEvents"
|
||||
resolver := func() error {
|
||||
// make sure Page events are enabled.
|
||||
if err := client.Page.Enable(ctx); err != nil {
|
||||
return err
|
||||
}
|
||||
// make sure Network events are enabled.
|
||||
if err := client.Network.Enable(ctx, nil); err != nil {
|
||||
return err
|
||||
}
|
||||
// create all clients for events.
|
||||
domContentEventFired, err := client.Page.DOMContentEventFired(ctx)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
defer domContentEventFired.Close() // nolint: errcheck
|
||||
loadEventFired, err := client.Page.LoadEventFired(ctx)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
defer loadEventFired.Close() // nolint: errcheck
|
||||
lifecycleEvent, err := client.Page.LifecycleEvent(ctx)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
defer lifecycleEvent.Close() // nolint: errcheck
|
||||
loadingFinished, err := client.Network.LoadingFinished(ctx)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
defer loadingFinished.Close() // nolint: errcheck
|
||||
if _, err := client.Page.Navigate(ctx, page.NewNavigateArgs(p.url)); err != nil {
|
||||
return err
|
||||
}
|
||||
// wait for all events.
|
||||
return xerrgroup.Run(
|
||||
func() error {
|
||||
_, err := domContentEventFired.Recv()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
p.logger.DebugOp(op, "event 'domContentEventFired' received")
|
||||
return nil
|
||||
},
|
||||
func() error {
|
||||
_, err := loadEventFired.Recv()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
p.logger.DebugOp(op, "event 'loadEventFired' received")
|
||||
return nil
|
||||
},
|
||||
func() error {
|
||||
const networkIdleEventName string = "networkIdle"
|
||||
for {
|
||||
ev, err := lifecycleEvent.Recv()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
p.logger.DebugfOp(op, "event '%s' received", ev.Name)
|
||||
if ev.Name == networkIdleEventName {
|
||||
break
|
||||
}
|
||||
}
|
||||
return nil
|
||||
},
|
||||
func() error {
|
||||
_, err := loadingFinished.Recv()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
p.logger.DebugOp(op, "event 'loadingFinished' received")
|
||||
return nil
|
||||
},
|
||||
)
|
||||
}
|
||||
if err := resolver(); err != nil {
|
||||
return xerror.New(op, err)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Compile-time checks to ensure type implements desired interfaces.
|
||||
var (
|
||||
_ = Print(new(chromePrint))
|
||||
)
|
||||
Reference in New Issue
Block a user