process load balancing: broken but in progress

internal/app/xhttp/pkg/context/context.go

@@ -13,7 +13,8 @@ import (
 	"github.com/thecodingmachine/gotenberg/internal/app/xhttp/pkg/resource"
 	"github.com/thecodingmachine/gotenberg/internal/pkg/conf"
 	"github.com/thecodingmachine/gotenberg/internal/pkg/normalize"
-	"github.com/thecodingmachine/gotenberg/internal/pkg/pm2"
+	"github.com/thecodingmachine/gotenberg/internal/pkg/prinery"
+	"github.com/thecodingmachine/gotenberg/internal/pkg/process"
 	"github.com/thecodingmachine/gotenberg/internal/pkg/xerror"
 	"github.com/thecodingmachine/gotenberg/internal/pkg/xlog"
 )
@@ -21,20 +22,31 @@ import (
 // Context extends the default echo.Context.
 type Context struct {
 	echo.Context
-	logger    xlog.Logger
-	config    conf.Config
-	processes []pm2.Process
-	resource  resource.Resource
-	startTime time.Time
+	logger         xlog.Logger
+	config         conf.Config
+	manager        process.Manager
+	chromePrinery  *prinery.Prinery
+	sofficePrinery *prinery.Prinery
+	resource       resource.Resource
+	startTime      time.Time
 }
 
 // New creates a new Context.
-func New(c echo.Context, logger xlog.Logger, config conf.Config, processes ...pm2.Process) Context {
+func New(
+	c echo.Context,
+	logger xlog.Logger,
+	config conf.Config,
+	manager process.Manager,
+	chromePrinery *prinery.Prinery,
+	sofficePrinery *prinery.Prinery,
+) Context {
 	return Context{
 		c,
 		logger,
 		config,
-		processes,
+		manager,
+		chromePrinery,
+		sofficePrinery,
 		resource.Resource{},
 		time.Now(),
 	}
@@ -77,17 +89,52 @@ func (ctx Context) Config() conf.Config {
 // one of the processes is not viable.
 func (ctx Context) ProcessesHealthcheck() error {
 	const op string = "context.Context.ProcessesHealthcheck"
-	for _, process := range ctx.processes {
-		if !process.IsViable() {
+	processes := ctx.manager.All()
+	for _, p := range processes {
+		if !ctx.manager.IsViable(p) {
 			return xerror.New(
 				op,
-				fmt.Errorf("'%s' is not viable", process.Fullname()),
+				fmt.Errorf("'%s' is not viable", p.ID()),
 			)
 		}
 	}
 	return nil
 }
 
+/*
+MustChromePrinery returns the instance of
+prinery.Prinery associated with the Context.
+
+This prinery.Prinery handles Google Chrome
+headless.
+
+It panics if no instance of prinery.Prinery.
+*/
+func (ctx Context) MustChromePrinery() *prinery.Prinery {
+	const op string = "context.Context.MustChromePrinery"
+	if ctx.chromePrinery == nil {
+		panic(fmt.Sprintf("%s: unable to retrieve the instance of Google Chrome Headless prinery.Prinery from our custom context.Context", op))
+	}
+	return ctx.chromePrinery
+}
+
+/*
+MustSofficePrinery returns the instance of
+prinery.Prinery associated with the Context.
+
+This prinery.Prinery handles LibreOffice
+headless.
+
+It panics if no instance of prinery.Prinery.
+*/
+func (ctx Context) MustSofficePrinery() *prinery.Prinery {
+	const op string = "context.Context.MustSofficePrinery"
+	if ctx.sofficePrinery == nil {
+		panic(fmt.Sprintf("%s: unable to retrieve the instance of LibreOffice Headless prinery.Prinery from our custom context.Context", op))
+	}
+	return ctx.sofficePrinery
+}
+
 // WithResource creates a resource.Resource and
 // adds it to the Context.
 func (ctx *Context) WithResource(directoryName string) error {

internal/app/xhttp/pkg/resource/arg.go

@@ -76,6 +76,34 @@ func ArgKeys() []ArgKey {
 	}
 }
 
+/*
+WaitTimeoutAndWaitDelayArg is a helper for retrieving
+the sum of "waitTimeout" and "waitDelay" arguments
+as float64.
+
+It also validates them against the application
+configuration.
+*/
+func WaitTimeoutAndWaitDelayArg(r Resource, config conf.Config) (float64, error) {
+	const op string = "resource.WaitTimeoutAndWaitDelayArg"
+	resolver := func() (float64, error) {
+		waitTimeout, err := WaitTimeoutArg(r, config)
+		if err != nil {
+			return waitTimeout, err
+		}
+		waitDelay, err := WaitDelayArg(r, config)
+		if err != nil {
+			return waitDelay, err
+		}
+		return waitTimeout + waitDelay, nil
+	}
+	combined, err := resolver()
+	if err != nil {
+		return combined, xerror.New(op, err)
+	}
+	return combined, nil
+}
+
 /*
 WaitTimeoutArg is a helper for retrieving
 the "waitTimeout" argument as float64.