Added note on how to access index.html on remote server (#2276)

esmvalcore/experimental/recipe_output.py

@@ -1,7 +1,9 @@
 """API for handing recipe output."""
 import base64
+import getpass
 import logging
 import os.path
+import sys
 from collections.abc import Mapping, Sequence
 from pathlib import Path
 from typing import Optional, Tuple, Type
@@ -228,6 +230,37 @@ def from_core_recipe_output(cls, recipe_output: dict):
 
         return cls(task_output, session=session, info=info)
 
+    def _log_ssh_html_info(self):
+        """Log information about accessing index.html on an SSH server."""
+        if 'SSH_CONNECTION' not in os.environ:
+            return
+        server_ip = os.environ['SSH_CONNECTION'].split()[2]
+        server_ip_env = '${server}'
+        server = f'{getpass.getuser()}@{server_ip_env}'
+        port = '31415'
+        port_env = '${port}'
+        command = (
+            f'server={server_ip} && port={port} && '
+            f'ssh -t -L {port_env}:localhost:{port_env} {server} '
+            f'{sys.executable} -m http.server {port_env} -d '
+            f'{self.session.session_dir}'
+        )
+        logger.info(
+            "It looks like you are connected to a remote machine via SSH. To "
+            "show the output html file, you can try the following command:"
+            "\n%s\nThen visit http://localhost:%s in your browser",
+            command,
+            port,
+        )
+        logger.info(
+            "If the port %s is already in use, you can replace it with any "
+            "other free one (e.g., 12789). If you are connected through a "
+            "jump host, replace the server IP address %s with your SSH server "
+            "name",
+            port,
+            server_ip,
+        )
+
     def write_html(self):
         """Write output summary to html document.
 
@@ -242,6 +275,7 @@ def write_html(self):
             file.write(html_dump)
 
         logger.info("Wrote recipe output to:\nfile://%s", filename)
+        self._log_ssh_html_info()
 
     def render(self, template=None):
         """Render output as html.

tests/sample_data/experimental/test_run_recipe.py

@@ -3,6 +3,8 @@
 Runs recipes using :meth:`esmvalcore.experimental.Recipe.run`.
 """
 
+import logging
+import os
 from contextlib import contextmanager
 from pathlib import Path
 
@@ -55,12 +57,20 @@ def recipe():
 
 
 @pytest.mark.use_sample_data
+@pytest.mark.parametrize('ssh', (True, False))
 @pytest.mark.parametrize('task', (None, 'example/ta'))
-def test_run_recipe(monkeypatch, task, recipe, tmp_path):
+def test_run_recipe(monkeypatch, task, ssh, recipe, tmp_path, caplog):
     """Test running a basic recipe using sample data.
 
     Recipe contains no provenance and no diagnostics.
     """
+    caplog.set_level(logging.INFO)
+    caplog.clear()
+    if ssh:
+        monkeypatch.setitem(os.environ, 'SSH_CONNECTION', '0.0 0 1.1 1')
+    else:
+        monkeypatch.delitem(os.environ, 'SSH_CONNECTION', raising=False)
+
     TAGS.set_tag_values(AUTHOR_TAGS)
 
     assert isinstance(recipe, Recipe)
@@ -97,6 +107,12 @@ def test_run_recipe(monkeypatch, task, recipe, tmp_path):
             cube = data_file.load_iris()
             assert isinstance(cube, iris.cube.CubeList)
 
+    msg = "It looks like you are connected to a remote machine via SSH."
+    if ssh:
+        assert msg in caplog.text
+    else:
+        assert msg not in caplog.text
+
 
 @pytest.mark.use_sample_data
 def test_run_recipe_diagnostic_failing(monkeypatch, recipe, tmp_path):