bskyweb additions (#296)

Add some minor bskyweb improvements, Mailmodo endpoint, Dockerfile for bskyweb, container image push

bskyweb/cmd/bskyweb/renderer.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"bytes"
+	"embed"
+	"errors"
+	"fmt"
+	"io"
+	"path/filepath"
+
+	"github.com/flosch/pongo2/v6"
+	"github.com/labstack/echo/v4"
+)
+
+type RendererLoader struct {
+	prefix string
+	fs     *embed.FS
+}
+
+func NewRendererLoader(prefix string, fs *embed.FS) pongo2.TemplateLoader {
+	return &RendererLoader{
+		prefix: prefix,
+		fs:     fs,
+	}
+}
+func (l *RendererLoader) Abs(_, name string) string {
+	// TODO: remove this workaround
+	// Figure out why this method is being called
+	// twice on template names resulting in a failure to resolve
+	// the template name.
+	if filepath.HasPrefix(name, l.prefix) {
+		return name
+	}
+	return filepath.Join(l.prefix, name)
+}
+
+func (l *RendererLoader) Get(path string) (io.Reader, error) {
+	b, err := l.fs.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("reading template %q failed: %w", path, err)
+	}
+	return bytes.NewReader(b), nil
+}
+
+type Renderer struct {
+	TemplateSet *pongo2.TemplateSet
+	Debug       bool
+}
+
+func NewRenderer(prefix string, fs *embed.FS, debug bool) *Renderer {
+	return &Renderer{
+		TemplateSet: pongo2.NewSet(prefix, NewRendererLoader(prefix, fs)),
+		Debug:       debug,
+	}
+}
+
+func (r Renderer) Render(w io.Writer, name string, data interface{}, c echo.Context) error {
+	var ctx pongo2.Context
+
+	if data != nil {
+		var ok bool
+		ctx, ok = data.(pongo2.Context)
+		if !ok {
+			return errors.New("no pongo2.Context data was passed")
+		}
+	}
+
+	var t *pongo2.Template
+	var err error
+
+	if r.Debug {
+		t, err = pongo2.FromFile(name)
+	} else {
+		t, err = r.TemplateSet.FromFile(name)
+	}
+
+	if err != nil {
+		return err
+	}
+
+	return t.ExecuteWriter(ctx, w)
+}