rough in a Bridgetown scanner

scanner/bridgetown.go

@@ -0,0 +1,31 @@
+package scanner
+
+import "github.com/pkg/errors"
+
+func configureBridgetown(sourceDir string, _ *ScannerConfig) (*SourceInfo, error) {
+	if !checksPass(sourceDir, dirContains("Gemfile", "bridgetown")) {
+		return nil, nil
+	}
+
+	s := &SourceInfo{
+		Family: "Bridgetown",
+		Port:   4000,
+		Statics: []Static{
+			{
+				GuestPath: "/app/output",
+				UrlPrefix: "/",
+			},
+		},
+	}
+
+	rubyVersion, err := extractRubyVersion("Gemfile.lock", "Gemfile", ".ruby_version")
+	if err != nil {
+		return nil, errors.Wrap(err, "failure extracting Ruby version")
+	}
+
+	vars := make(map[string]interface{})
+	vars["rubyVersion"] = rubyVersion
+	s.Files = templatesExecute("templates/bridgetown", vars)
+
+	return s, nil
+}

scanner/ruby.go

@@ -5,6 +5,8 @@ import (
 	"os/exec"
 	"regexp"
 	"strings"
+
+	"github.com/pkg/errors"
 )
 
 func configureRuby(sourceDir string, config *ScannerConfig) (*SourceInfo, error) {
@@ -18,23 +20,8 @@ func configureRuby(sourceDir string, config *ScannerConfig) (*SourceInfo, error)
 	}
 
 	rubyVersion, err := extractRubyVersion("Gemfile.lock", "Gemfile", ".ruby_version")
-
-	if err != nil || rubyVersion == "" {
-		rubyVersion = "3.1.2"
-
-		out, err := exec.Command("ruby", "-v").Output()
-		if err == nil {
-
-			version := strings.TrimSpace(string(out))
-			re := regexp.MustCompile(`ruby (?P<version>[\d.]+)`)
-			m := re.FindStringSubmatch(version)
-
-			for i, name := range re.SubexpNames() {
-				if len(m) > 0 && name == "version" {
-					rubyVersion = m[i]
-				}
-			}
-		}
+	if err != nil {
+		return nil, errors.Wrap(err, "failure extracting Ruby version")
 	}
 
 	vars := make(map[string]interface{})
@@ -101,5 +88,23 @@ func extractRubyVersion(lockfilePath string, gemfilePath string, rubyVersionPath
 		}
 	}
 
+	if version == "" {
+		version = "3.3.5"
+
+		out, err := exec.Command("ruby", "-v").Output()
+		if err == nil {
+
+			versionString := strings.TrimSpace(string(out))
+			re := regexp.MustCompile(`ruby (?P<version>[\d.]+)`)
+			m := re.FindStringSubmatch(versionString)
+
+			for i, name := range re.SubexpNames() {
+				if len(m) > 0 && name == "version" {
+					version = m[i]
+				}
+			}
+		}
+	}
+
 	return version, nil
 }

scanner/scanner.go

@@ -121,6 +121,7 @@ func Scan(sourceDir string, config *ScannerConfig) (*SourceInfo, error) {
 		   since they might mix languages or have a Dockerfile that
 			 doesn't work with Fly */
 		configureDockerfile,
+		configureBridgetown,
 		configureLucky,
 		configureRuby,
 		configureGo,

scanner/templates/bridgetown/Dockerfile

@@ -0,0 +1,29 @@
+ARG RUBY_VERSION={{ .rubyVersion }}
+FROM ruby:$RUBY_VERSION-slim as base
+
+ENV VOLTA_HOME=/usr/local
+
+RUN apt-get update &&\
+    apt-get install --yes build-essential git curl
+
+RUN curl https://get.volta.sh | bash &&\
+    volta install node@lts yarn@latest
+
+WORKDIR /app
+
+FROM base as gems
+COPY Gemfile* .
+RUN bundle install
+
+FROM base
+COPY . .
+COPY --from=base $VOLTA_HOME/bin $VOLTA_HOME/bin
+COPY --from=base $VOLTA_HOME/tools $VOLTA_HOME/tools
+COPY --from=base /app /app
+COPY --from=gems /usr/local/bundle /usr/local/bundle
+
+RUN yarn install
+RUN bundle exec bridgetown frontend:build
+
+EXPOSE 4000
+CMD bundle exec bridgetown start