SDK/DSL/Compiler - Fixed compilation when using ContainerOp.after

Fixes kubeflow#941

sdk/python/kfp/compiler/compiler.py

@@ -551,6 +551,8 @@ def _compile(self, pipeline_func):
       if op.output is not None:
         op.output.name = K8sHelper.sanitize_k8s_name(op.output.name)
         op.output.op_name = K8sHelper.sanitize_k8s_name(op.output.op_name)
+      if op.dependent_op_names:
+        op.dependent_op_names = [K8sHelper.sanitize_k8s_name(name) for name in op.dependent_op_names]
       if op.file_outputs is not None:
         sanitized_file_outputs = {}
         for key in op.file_outputs.keys():

sdk/python/tests/compiler/compiler_tests.py

@@ -236,3 +236,17 @@ def test_py_retry(self):
   def test_py_image_pull_secret(self):
     """Test pipeline imagepullsecret."""
     self._test_py_compile('imagepullsecret')
+
+  def test_compile_pipeline_with_after(self):
+    def op():
+      return dsl.ContainerOp(
+        name='Some component name',
+        image='image'
+      )
+
+    @dsl.pipeline(name='Pipeline', description='')
+    def pipeline():
+      task1 = op()
+      task2 = op().after(task1)
+
+    compiler.Compiler()._compile(pipeline)