changes to detect jre version from build.gradle

cmd/create.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"bufio"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -59,6 +60,7 @@ type createCmd struct {
 }
 
 func newCreateCmd() *cobra.Command {
+	log.SetLevel(log.TraceLevel)
 	cc := &createCmd{}
 
 	cmd := &cobra.Command{
@@ -194,8 +196,8 @@ func (cc *createCmd) detectLanguage() (*config.DraftConfig, string, error) {
 				if lang.Language == "Java" {
 
 					selection := &promptui.Select{
-						Label: "Linguist detected Java, are you using maven or gradle?",
-						Items: []string{"gradle", "maven"},
+						Label: "Linguist detected Java, are you using maven or gradle or gradle wrapper?",
+						Items: []string{"gradle", "maven", "gradlew"},
 					}
 
 					_, selectResponse, err := selection.Run()
@@ -205,6 +207,8 @@ func (cc *createCmd) detectLanguage() (*config.DraftConfig, string, error) {
 
 					if selectResponse == "gradle" {
 						lang.Language = "Gradle"
+					} else if selectResponse == "gradlew" {
+						lang.Language = "Gradlew"
 					}
 				}
 			}
@@ -349,6 +353,8 @@ func (cc *createCmd) createFiles(detectedLang *config.DraftConfig, lowerLang str
 		return errors.New("can only pass in one of --dockerfile-only and --deployment-only")
 	}
 
+	cc.detectDefaults(detectedLang, lowerLang)
+
 	if cc.skipFileDetection {
 		if !cc.deploymentOnly {
 			err := cc.generateDockerfile(detectedLang, lowerLang)
@@ -429,6 +435,34 @@ func (cc *createCmd) createFiles(detectedLang *config.DraftConfig, lowerLang str
 	return nil
 }
 
+func (cc *createCmd) detectDefaults(detectedLang *config.DraftConfig, lowerLang string) {
+	if lowerLang == "gradlew" || lowerLang == "gradle" {
+		// read from build.gradle and detect version
+		f, err := os.Open("build.gradle")
+		if err != nil {
+			log.Warn("Unable to read build.gradle, skipping detection")
+			return
+		}
+		defer f.Close()
+		scanner := bufio.NewScanner(f)
+		for scanner.Scan() {
+			line := scanner.Text()
+			if strings.Contains(line, "sourceCompatibility") {
+				detectedVersion := strings.Split(line, " = ")[1] // sourceCompatibility = '1.8'
+				detectedVersion = strings.Trim(detectedVersion, "'")
+				detectedVersion = "jdk" + detectedVersion
+				detectedDefaults := []config.BuilderVarDefault{
+					{Name: "VERSION", Value: detectedVersion},
+				}
+				log.Info("detected version %s", detectedVersion)
+				log.Info("Detected %s from build.gradle for %s project", detectedVersion, lowerLang)
+				detectedLang.DetectedDefaults = detectedDefaults
+				return
+			}
+		}
+	}
+}
+
 func init() {
 	rootCmd.AddCommand(newCreateCmd())
 }

pkg/config/draftconfig.go

@@ -10,6 +10,7 @@ type DraftConfig struct {
 	NameOverrides    []FileNameOverride  `yaml:"nameOverrides"`
 	Variables        []BuilderVar        `yaml:"variables"`
 	VariableDefaults []BuilderVarDefault `yaml:"variableDefaults"`
+	DetectedDefaults []BuilderVarDefault `yaml:"detectedDefaults"`
 
 	nameOverrideMap map[string]string
 }

pkg/prompts/prompts.go

@@ -54,7 +54,13 @@ func RunPromptsFromConfigWithSkipsIO(config *config.DraftConfig, varsToSkip []st
 			}
 			inputs[promptVariableName] = input
 		} else {
-			defaultValue := GetVariableDefaultValue(promptVariableName, config.VariableDefaults, inputs)
+			defaultValue := ""
+			detectedDefaultValue := GetDetectedDefaultValue(promptVariableName, config.DetectedDefaults, inputs)
+			if detectedDefaultValue != "" {
+				defaultValue = detectedDefaultValue
+			} else {
+				defaultValue = GetVariableDefaultValue(promptVariableName, config.VariableDefaults, inputs)
+			}
 
 			stringInput, err := RunDefaultableStringPrompt(customPrompt, defaultValue, nil, Stdin, Stdout)
 			if err != nil {
@@ -74,6 +80,21 @@ func RunPromptsFromConfigWithSkipsIO(config *config.DraftConfig, varsToSkip []st
 	return inputs, nil
 }
 
+func GetDetectedDefaultValue(variableName string, detectedDefaults []config.BuilderVarDefault, inputs map[string]string) string {
+	defaultValue := ""
+	for _, detectedDefault := range detectedDefaults {
+		if detectedDefault.Name == variableName {
+			defaultValue = detectedDefault.Value
+			log.Debugf("setting default value for %s to %s from detected default rule", variableName, defaultValue)
+			if detectedDefault.ReferenceVar != "" && inputs[detectedDefault.ReferenceVar] != "" {
+				defaultValue = inputs[detectedDefault.ReferenceVar]
+				log.Debugf("setting default value for %s to %s from referenceVar %s", variableName, defaultValue, detectedDefault.ReferenceVar)
+			}
+		}
+	}
+	return defaultValue
+}
+
 // GetVariableDefaultValue returns the default value for a variable, if one is set in variableDefaults from a ReferenceVar or literal VariableDefault.Value in that order.
 func GetVariableDefaultValue(variableName string, variableDefaults []config.BuilderVarDefault, inputs map[string]string) string {
 	defaultValue := ""

template/dockerfiles/gradlew/.dockerignore

@@ -0,0 +1,2 @@
+Dockerfile
+charts/

template/dockerfiles/gradlew/Dockerfile

@@ -0,0 +1,17 @@
+FROM gradle:{{BUILDERVERSION}} as BUILD
+
+COPY --chown=gradle:gradle . /project
+COPY gradlew gradlew
+COPY gradle/wrapper gradle/wrapper
+RUN chmod +x gradle/wrapper
+RUN chmod +x gradlew
+RUN ./gradlew -i -s -b /project/build.gradle clean build
+
+FROM eclipse-temurin:{{VERSION}}
+ENV PORT {{PORT}}
+EXPOSE {{PORT}}
+
+COPY --from=BUILD /project/build/libs/* /opt/
+WORKDIR /opt/
+RUN ls -l
+CMD ["/bin/bash", "-c", "find -type f -name '*SNAPSHOT.jar' | xargs java -jar"]

template/dockerfiles/gradlew/draft.yaml

@@ -0,0 +1,22 @@
+language: gradlew
+displayName: Gradlew
+nameOverrides:
+  - path: "dockerignore"
+    prefix: "."
+variables:
+  - name: "PORT"
+    description: "the port exposed in the application"
+    type: int
+  - name: "BUILDERVERSION"
+    description: "the version of gradle used during the builder stage to generate the executable"
+    exampleValues: ["jdk8","jdk11","jdk17","jdk19"]
+  - name: "VERSION"
+    description: "the version of openjdk used by the application"
+    exampleValues: ["8-jre","11-jre","17-jre","19-jre"]
+variableDefaults:
+  - name: "BUILDERVERSION"
+    value: "jdk11"
+  - name: "VERSION"
+    value: "11-jre"
+  - name: "PORT"
+    value: "80"