cli: adds option to get logs of a specific step

* Closes reanahub#369

reana_client/api/client.py

@@ -289,12 +289,13 @@ def upload_file(workflow_id, file_, file_name, access_token):
         raise e
 
 
-def get_workflow_logs(workflow_id, access_token):
+def get_workflow_logs(workflow_id, access_token, steps=None):
     """Get logs from a workflow engine."""
     try:
         (response,
             http_response) = current_rs_api_client.api.get_workflow_logs(
                 workflow_id_or_name=workflow_id,
+                steps=steps or None,
                 access_token=access_token).result()
 
         if http_response.status_code == 200:

reana_client/cli/workflow.py

@@ -129,7 +129,8 @@ def workflow_workflows(ctx, sessions, _filter, output_format, access_token,
         response = get_workflows(access_token, type, bool(verbose), block_size)
         verbose_headers = ['id', 'user', 'size']
         headers = {
-            'batch': ['name', 'run_number', 'created', 'status'],
+            'batch': ['name', 'run_number', 'created', 'started', 'completed',
+                      'status'],
             'interactive': ['name', 'run_number', 'created', 'session_type',
                             'session_uri']
         }
@@ -547,6 +548,8 @@ def add_data_from_reponse(row, data, headers):
             [name,
              run_number,
              row['created'],
+             row['progress']['run_started_at'],
+             row['progress']['run_finished_at'],
              row['status'],
              render_progress(finished_jobs, total_jobs)])))
         return data
@@ -583,7 +586,8 @@ def add_verbose_data_from_response(response, verbose_headers,
                 parsed_filters = parse_parameters(_filter)
                 _filter = [item['column_name'] for item in parsed_filters]
             response = get_workflow_status(workflow, access_token)
-            headers = ['name', 'run_number', 'created', 'status', 'progress']
+            headers = ['name', 'run_number', 'created', 'started', 'completed',
+                       'status', 'progress']
             verbose_headers = ['id', 'user', 'command']
             data = []
             if not isinstance(response, list):
@@ -627,9 +631,16 @@ def add_verbose_data_from_response(response, verbose_headers,
     count=True,
     help='Get output in JSON format.')
 @add_access_token_options
+@click.option(
+    '-s',
+    '--step',
+    'steps',
+    multiple=True,
+    help='Get logs of a specific step.')
 @check_connection
 @click.pass_context
-def workflow_logs(ctx, workflow, access_token, json_format):  # noqa: D301
+def workflow_logs(ctx, workflow, access_token, json_format,
+                  steps=None):  # noqa: D301
     """Get  workflow logs.
 
     The `logs` command allows to retrieve logs of running workflow. Note that
@@ -638,15 +649,15 @@ def workflow_logs(ctx, workflow, access_token, json_format):  # noqa: D301
 
     Examples: \n
     \t $ reana-client logs -w myanalysis.42
+    \t $ reana-client logs -w myanalysis.42 -s 1st_step
     """
     from reana_client.api.client import get_workflow_logs
     logging.debug('command: {}'.format(ctx.command_path.replace(" ", ".")))
     for p in ctx.params:
         logging.debug('{param}: {value}'.format(param=p, value=ctx.params[p]))
-
     if workflow:
         try:
-            response = get_workflow_logs(workflow, access_token)
+            response = get_workflow_logs(workflow, access_token, steps or None)
             workflow_logs = json.loads(response['logs'])
             if json_format:
                 click.echo(json.dumps(workflow_logs, indent=2))
@@ -657,6 +668,10 @@ def workflow_logs(ctx, workflow, access_token, json_format):  # noqa: D301
                 click.echo(workflow_logs['workflow_logs'])
 
             first = True
+            if len(workflow_logs['job_logs'].items()) == 0 and steps:
+                click.echo(
+                    click.style('Workflow logs of step(s) {} were not found.'
+                                .format(','.join(steps)), fg='red'))
             for job_id, job_logs in workflow_logs['job_logs'].items():
                 if job_logs:
                     if first: