Merge pull request #1 from chrismgrayftsinc/spring-components

Add support for spring.components files

spring_image.bzl

@@ -124,10 +124,20 @@ def tar_jars(ctx, files, out):
     java_runtime = ctx.attr._jdk[java_common.JavaRuntimeInfo]
     jar_path = "%s/bin/jar" % java_runtime.java_home
     paths = [f.path for f in files]
+    spring_components_file_path = "spring.components"
+    spring_components_file = ctx.actions.declare_file(spring_components_file_path)
     ctx.actions.run_shell(
         inputs = ctx.files._jdk + files,
+        outputs = [spring_components_file],
+        command = "touch {file}; for i in {all_paths}; do {jar} xf $i && if [ -s META-INF/spring.components ]; then cat META-INF/spring.components >> {file}; fi; done".format(file = spring_components_file.path, jar = jar_path, all_paths = " ".join(paths)),
+    )
+
+    ctx.actions.run_shell(
+        inputs = ctx.files._jdk + files + [spring_components_file],
         outputs = [out],
-        command = 'tar cf %s -T /dev/null && for i in %s; do %s xf ${i} && %s tf ${i} | tar rf %s --transform "s,^,BOOT-INF/classes/," -T -; done' % (out.path, " ".join(paths), jar_path, jar_path, out.path),
+        # Create an empty tarball, then extract all the jars and append the contents into it.
+        # TODO: get rid of the hardcoded bazel-out path in the first transform.
+        command = 'tar cf {out} -T /dev/null && if [ -s {scf} ]; then tar rhf {out} --transform "s,bazel-out/k8-fastbuild/bin/,BOOT-INF/classes/META-INF/," {scf}; fi && for i in {all_paths}; do {jar} xf $i && {jar} tf $i | tar rf {out} --transform "s,^,BOOT-INF/classes/," -T -; done'.format(out = out.path, all_paths = " ".join(paths), jar = jar_path, scf = spring_components_file.path),
     )
 
 def _application_copier_rule_impl(ctx):