cli: show output of docker build (#882)

Show output of docker build by making use of docker-py's low level API

fixes #785 

Co-authored-by: Ivo Jimenez <[email protected]>

Author: nicolecastillo

src/popper/runner_host.py

@@ -212,9 +212,17 @@ def _create_container(self, cid, step):
         if build:
             log.info(f"[{step.id}] docker build {img}:{tag} {build_ctx_path}")
             if not self._config.dry_run:
-                self._d.images.build(
-                    path=build_ctx_path, tag=f"{img}:{tag}", rm=True, pull=True
+                streamer = self._d.api.build(
+                    decode=True, path=build_ctx_path, tag=f"{img}:{tag}", rm=True,
                 )
+                for chunk in streamer:
+                    if self._config.quiet:
+                        continue
+                    if "stream" in chunk:
+                        lines = [line for line in chunk["stream"].splitlines() if line]
+                        for line in lines:
+                            log.step_info(line.strip())
+
         elif not self._config.skip_pull and not step.skip_pull:
             log.info(f"[{step.id}] docker pull {img}:{tag}")
             if not self._config.dry_run:

src/test/test_runner_host.py

@@ -275,10 +275,13 @@ def test_get_build_info(self):
     def test_docker_basic_run(self):
         repo = self.mk_repo()
         conf = ConfigLoader.load(workspace_dir=repo.working_dir)
+        test_string = "STEP_INFO:popper:Successfully tagged popperized/bin:master"
 
         with WorkflowRunner(conf) as r:
             wf_data = {"steps": [{"uses": "popperized/bin/sh@master", "args": ["ls"],}]}
-            r.run(WorkflowParser.parse(wf_data=wf_data))
+            with self.assertLogs(log, level="STEP_INFO") as cm:
+                r.run(WorkflowParser.parse(wf_data=wf_data))
+            self.assertTrue(test_string in cm.output, f"Got cmd output: {cm.output}")
 
             wf_data = {
                 "steps": [
@@ -303,6 +306,13 @@ def test_docker_basic_run(self):
             }
             self.assertRaises(SystemExit, r.run, WorkflowParser.parse(wf_data=wf_data))
 
+        conf = ConfigLoader.load(workspace_dir=repo.working_dir, quiet=True)
+        with WorkflowRunner(conf) as r:
+            wf_data = {"steps": [{"uses": "popperized/bin/sh@master", "args": ["ls"],}]}
+            with self.assertLogs(log, level="STEP_INFO") as cm:
+                r.run(WorkflowParser.parse(wf_data=wf_data))
+            self.assertTrue(test_string not in cm.output)
+
         repo.close()
         shutil.rmtree(repo.working_dir, ignore_errors=True)