snapshot of https://github.com/cortezaproject/corteza.git (2024.9.x, 2026-09-18; blobs > 131072B omitted)

server/system/renderer/gotenbergPDF.go

@@ -0,0 +1,387 @@
+package renderer
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"strings"
+	"sync"
+
+	"github.com/cortezaproject/corteza/server/system/types"
+)
+
+type (
+	gotenbergPDF struct {
+		url string
+		def DriverDefinition
+	}
+	gotenbergPDFDriver struct {
+		url string
+	}
+)
+
+// Gotenberg 7+ serves HTML conversion on the chromium module route, older (v6)
+// deployments only expose /convert/html; the working route is detected on
+// first render and cached per base URL
+var gotenbergEndpoints = sync.Map{}
+
+const (
+	gotenbergModernEndpoint = "/forms/chromium/convert/html"
+	gotenbergLegacyEndpoint = "/convert/html"
+)
+
+// @todo healthcheck, different input data formats
+func newGotenbergPDF(url string) driverFactory {
+	return &gotenbergPDF{
+		url: url,
+
+		def: DriverDefinition{
+			Name: "gotenbergPDF",
+			InputTypes: []types.DocumentType{
+				types.DocumentTypePlain,
+				types.DocumentTypeHTML,
+			},
+			OutputTypes: []types.DocumentType{
+				types.DocumentTypePDF,
+			},
+		},
+	}
+}
+
+func (d *gotenbergPDF) Define() DriverDefinition {
+	return d.def
+}
+
+func (d *gotenbergPDF) CanRender(t types.DocumentType) bool {
+	for _, i := range d.def.InputTypes {
+		if i == t {
+			return true
+		}
+	}
+	return false
+}
+
+func (d *gotenbergPDF) CanProduce(t types.DocumentType) bool {
+	for _, o := range d.def.OutputTypes {
+		if o == t {
+			return true
+		}
+	}
+	return false
+}
+
+func (d *gotenbergPDF) Driver() driver {
+	return &gotenbergPDFDriver{
+		url: d.url,
+	}
+}
+
+func (d *gotenbergPDFDriver) Render(ctx context.Context, pl *driverPayload) (io.ReadSeeker, error) {
+	// HTTP request body stuff
+	body := &bytes.Buffer{}
+	writer := multipart.NewWriter(body)
+	// index.html is required by the rendering container; Gotenberg 7+ requires
+	// the "files" form field name, v6 accepts any name
+	part, err := writer.CreateFormFile("files", "index.html")
+	if err != nil {
+		return nil, err
+	}
+	err = d.prepareContent(part, pl)
+	if err != nil {
+		return nil, err
+	}
+
+	// Optional header/footer documents rendered with the same variables/partials
+	if pl.Header != nil {
+		hPart, err := writer.CreateFormFile("files", "header.html")
+		if err != nil {
+			return nil, err
+		}
+
+		if err = d.prepareAux(hPart, pl, pl.Header); err != nil {
+			return nil, err
+		}
+	}
+
+	if pl.Footer != nil {
+		fPart, err := writer.CreateFormFile("files", "footer.html")
+		if err != nil {
+			return nil, err
+		}
+
+		if err = d.prepareAux(fPart, pl, pl.Footer); err != nil {
+			return nil, err
+		}
+	}
+
+	// Document configurations
+	err = d.applyOptions(writer, pl.Options)
+	if err != nil {
+		return nil, err
+	}
+
+	err = writer.Close()
+	if err != nil {
+		return nil, err
+	}
+
+	// HTTP request header stuff
+	// @todo make sure to use the propper endpoint when you add support
+	//       for different inputs.
+	url := d.url
+	if n, has := pl.Options["url"]; has {
+		url = n
+	}
+
+	endpoints := []string{gotenbergModernEndpoint, gotenbergLegacyEndpoint}
+	if e, has := gotenbergEndpoints.Load(url); has && e == gotenbergLegacyEndpoint {
+		endpoints = []string{gotenbergLegacyEndpoint, gotenbergModernEndpoint}
+	}
+
+	var resp *http.Response
+	for _, e := range endpoints {
+		req, err := http.NewRequestWithContext(ctx, "POST", url+e, bytes.NewReader(body.Bytes()))
+		if err != nil {
+			return nil, err
+		}
+		req.Header.Set("Content-Type", writer.FormDataContentType())
+
+		resp, err = http.DefaultClient.Do(req)
+		if err != nil {
+			return nil, err
+		}
+
+		// 404 means the route doesn't exist on this Gotenberg version; try the other one
+		if resp.StatusCode == http.StatusNotFound {
+			resp.Body.Close()
+			resp = nil
+			continue
+		}
+
+		gotenbergEndpoints.Store(url, e)
+		break
+	}
+
+	if resp == nil {
+		return nil, fmt.Errorf("gotenberg render failed: no compatible endpoint found on %s", url)
+	}
+
+	defer resp.Body.Close()
+	ss, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("gotenberg render failed: %s: %s", resp.Status, strings.TrimSpace(string(ss)))
+	}
+
+	return bytes.NewReader(ss), nil
+}
+
+func (d *gotenbergPDFDriver) prepareContent(w io.Writer, pl *driverPayload) error {
+	t, err := preprocHTMLTemplate(pl)
+	if err != nil {
+		return err
+	}
+
+	return t.Execute(w, pl.Variables)
+}
+
+// prepareAux renders an auxiliary document (header/footer) with pl's variables
+func (d *gotenbergPDFDriver) prepareAux(w io.Writer, pl *driverPayload, src io.Reader) error {
+	aux := *pl
+	aux.Template = src
+	return d.prepareContent(w, &aux)
+}
+
+func (d *gotenbergPDFDriver) applyOptions(mw *multipart.Writer, opts map[string]string) (err error) {
+	if opts == nil {
+		return nil
+	}
+
+	for k, v := range opts {
+		switch k {
+		case "marginTop",
+			"marginBottom",
+			"marginLeft",
+			"marginRight":
+			err = d.addFormField(mw, k, v)
+
+		case "marginY":
+			err = d.addFormField(mw, "marginTop", v)
+			if err != nil {
+				return err
+			}
+			err = d.addFormField(mw, "marginBottom", v)
+
+		case "marginX":
+			err = d.addFormField(mw, "marginLeft", v)
+			if err != nil {
+				return err
+			}
+			err = d.addFormField(mw, "marginRight", v)
+
+		case "margin":
+			err = d.addFormField(mw, "marginTop", v)
+			if err != nil {
+				return err
+			}
+			err = d.addFormField(mw, "marginBottom", v)
+			if err != nil {
+				return err
+			}
+			err = d.addFormField(mw, "marginLeft", v)
+			if err != nil {
+				return err
+			}
+			err = d.addFormField(mw, "marginRight", v)
+
+		case "documentSize":
+			w, h := d.documentDimensions(v)
+			if w+h != "" {
+				err = d.addFormField(mw, "paperWidth", w)
+				if err != nil {
+					return err
+				}
+				err = d.addFormField(mw, "paperHeight", h)
+			}
+
+		case "documentWidth":
+			err = d.addFormField(mw, "paperWidth", v)
+
+		case "documentHeight":
+			err = d.addFormField(mw, "paperHeight", v)
+
+		case "contentScale":
+			err = d.addFormField(mw, "scale", v)
+
+		case "orientation":
+			if v == "landscape" {
+				err = d.addFormField(mw, "landscape", "true")
+			} else {
+				err = d.addFormField(mw, "landscape", "false")
+			}
+		}
+
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (d *gotenbergPDFDriver) addFormField(mw *multipart.Writer, k, v string) error {
+	w, err := mw.CreateFormField(k)
+	if err != nil {
+		return err
+	}
+
+	_, err = w.Write([]byte(v))
+	return err
+}
+
+// documentDimensions returns the ISO216 standard document dimensions in inches (Gotenberg uses inches)
+func (d *gotenbergPDFDriver) documentDimensions(isoDoc string) (string, string) {
+	switch strings.ToLower(isoDoc) {
+	// A series
+	case "a0":
+		return "33.1", "46.8"
+	case "a1":
+		return "23.4", "33.1"
+	case "a2":
+		return "16.5", "23.4"
+	case "a3":
+		return "11.7", "16.5"
+	case "a4":
+		return "8.3", "11.7"
+	case "a5":
+		return "5.8", "8.3"
+	case "a6":
+		return "4.1", "5.8"
+	case "a7":
+		return "2.9", "4.1"
+	case "a8":
+		return "2.0", "2.9"
+	case "a9":
+		return "1.5", "2.0"
+	case "a10":
+		return "1.0", "1.5"
+
+	// B series
+	case "b0":
+		return "39.4", "55.7"
+	case "b1":
+		return "27.8", "39.4"
+	case "b2":
+		return "19.7", "27.8"
+	case "b3":
+		return "13.9", "19.7"
+	case "b4":
+		return "9.8", "13.9"
+	case "b5":
+		return "6.9", "9.8"
+	case "b6":
+		return "4.9", "6.9"
+	case "b7":
+		return "3.5", "4.9"
+	case "b8":
+		return "2.4", "3.5"
+	case "b9":
+		return "1.7", "2.4"
+	case "b10":
+		return "1.2", "1.7"
+
+	// C series
+	case "c0":
+		return "36.1", "51.1"
+	case "c1":
+		return "25.5", "36.1"
+	case "c2":
+		return "18.0", "25.5"
+	case "c3":
+		return "12.8", "18.0"
+	case "c4":
+		return "9.0", "12.8"
+	case "c5":
+		return "6.4", "9.0"
+	case "c6":
+		return "4.5", "6.4"
+	case "c7":
+		return "3.2", "4.5"
+	case "c8":
+		return "2.2", "3.2"
+	case "c9":
+		return "1.6", "2.2"
+	case "c10":
+		return "1.1", "1.6"
+
+		// ANSI
+	case "ansi a":
+		return "8.5", "11"
+	case "ansi b":
+		return "11", "17"
+	case "ansi c":
+		return "17", "22"
+	case "ansi d":
+		return "22", "34"
+	case "ansi e":
+		return "34", "44"
+
+	// Proprietary NA
+	case "junior legal":
+		return "8", "5"
+	case "letter":
+		return "8.5", "11"
+	case "legal":
+		return "8.5", "14"
+	case "tabloid":
+		return "11", "17"
+	}
+
+	// This will fallback to the default (A4)
+	return "", ""
+}