Reuse same dockerfile gen logic between prelude and steps

As now we build only when necessary, we need to make sure the images are
built similarly. The discrepancies between the two are less now, and
they can share the same logic.

This fixes a regresion where when no prelude is defined, the build
context isn't copied over

pkg/compiler/artifact_test.go

@@ -96,6 +96,7 @@ ENV PACKAGE_CATEGORY=app-admin`))
 			Expect(err).ToNot(HaveOccurred())
 			Expect(dockerfile).To(Equal(`
 FROM luet/base
+COPY . /luetbuild
 WORKDIR /luetbuild
 ENV PACKAGE_NAME=enman
 ENV PACKAGE_VERSION=1.4.0

pkg/compiler/backend/simpledocker_test.go

@@ -87,6 +87,7 @@ ENV PACKAGE_CATEGORY=app-admin`))
 			Expect(err).ToNot(HaveOccurred())
 			Expect(dockerfile).To(Equal(`
 FROM luet/base
+COPY . /luetbuild
 WORKDIR /luetbuild
 ENV PACKAGE_NAME=enman
 ENV PACKAGE_VERSION=1.4.0

pkg/compiler/spec.go

@@ -203,10 +203,9 @@ func (cs *LuetCompilationSpec) CopyRetrieves(dest string) error {
 	return err
 }
 
-// TODO: docker build image first. Then a backend can be used to actually spin up a container with it and run the steps within
+func (cs *LuetCompilationSpec) genDockerfile(image string, steps []string) string {
-func (cs *LuetCompilationSpec) RenderBuildImage() (string, error) {
 	spec := `
-FROM ` + cs.GetSeedImage() + `
+FROM ` + image + `
 COPY . /luetbuild
 WORKDIR /luetbuild
 ENV PACKAGE_NAME=` + cs.Package.GetName() + `
@@ -231,45 +230,23 @@ ADD ` + s + ` /luetbuild/`
 ENV ` + s
 	}
 
-	for _, s := range cs.GetPreBuildSteps() {
+	for _, s := range steps {
 		spec = spec + `
 RUN ` + s
 	}
-	return spec, nil
+	return spec
+}
+
+// TODO: docker build image first. Then a backend can be used to actually spin up a container with it and run the steps within
+func (cs *LuetCompilationSpec) RenderBuildImage() (string, error) {
+
+	return cs.genDockerfile(cs.GetSeedImage(), cs.GetPreBuildSteps()), nil
+
 }
 
 // TODO: docker build image first. Then a backend can be used to actually spin up a container with it and run the steps within
 func (cs *LuetCompilationSpec) RenderStepImage(image string) (string, error) {
-	spec := `
+	return cs.genDockerfile(image, cs.BuildSteps()), nil
-FROM ` + image + `
-WORKDIR /luetbuild
-ENV PACKAGE_NAME=` + cs.Package.GetName() + `
-ENV PACKAGE_VERSION=` + cs.Package.GetVersion() + `
-ENV PACKAGE_CATEGORY=` + cs.Package.GetCategory()
-
-	if len(cs.Retrieve) > 0 {
-		for _, s := range cs.Retrieve {
-			//var file string
-			// if helpers.IsValidUrl(s) {
-			// 	file = s
-			// } else {
-			// 	file = cs.Rel(s)
-			// }
-			spec = spec + `
-ADD ` + s + ` /luetbuild/`
-		}
-	}
-
-	for _, s := range cs.Env {
-		spec = spec + `
-ENV ` + s
-	}
-	for _, s := range cs.BuildSteps() {
-		spec = spec + `
-RUN ` + s
-	}
-
-	return spec, nil
 }
 
 func (cs *LuetCompilationSpec) WriteBuildImageDefinition(path string) error {

pkg/compiler/spec_test.go

@@ -96,6 +96,7 @@ ENV test=1`))
 			Expect(err).ToNot(HaveOccurred())
 			Expect(dockerfile).To(Equal(`
 FROM luet/base
+COPY . /luetbuild
 WORKDIR /luetbuild
 ENV PACKAGE_NAME=enman
 ENV PACKAGE_VERSION=1.4.0
@@ -169,6 +170,7 @@ ENV test=1`))
 
 		Expect(dockerfile).To(Equal(`
 FROM luet/base
+COPY . /luetbuild
 WORKDIR /luetbuild
 ENV PACKAGE_NAME=a
 ENV PACKAGE_VERSION=1.0