[IMP] client to return mocked server version

README.md

@@ -35,6 +35,16 @@ There are two clients:
 * a python client, which only depends on the `requests` library.
   It should work with any python version supported by `requests`.
 
+### mock server
+
+Odoo [checks for `wkhtmltopdf`'s version on start](https://github.com/odoo/odoo/blob/12.0/odoo/addons/base/models/ir_actions_report.py#L58).
+
+In a CI context, we don't necessarily want to run the `kwkhtmtopdf` container.
+But we definitely want Odoo to start.
+
+To support this case, you can set `KWKHTMLTOPDF_SERVER_URL=MOCK`: the client will
+then return `wkhtmltopdf 0.12.5 (mock)` when called with `--version` flag.
+
 ## Quick start
 
 ### Run the server

client/go/kwkhtmltopdf_client.go

@@ -40,6 +40,9 @@ func do() error {
 	serverURL := os.Getenv("KWKHTMLTOPDF_SERVER_URL")
 	if serverURL == "" {
 		return errors.New("KWKHTMLTOPDF_SERVER_URL not set")
+	} else if serverURL == "MOCK" {
+		os.Stdout.WriteString("wkhtmltopdf 0.12.5 (mock)\n")
+		return nil
 	}
 
 	// detect if last argument is output file, and create it

client/python/kwkhtmltopdf_client.py

@@ -26,6 +26,13 @@ class ServerError(Error):
 
 def wkhtmltopdf(args):
     url = os.getenv("KWKHTMLTOPDF_SERVER_URL")
+
+    if url == "":
+        raise UsageError("KWKHTMLTOPDF_SERVER_URL not set")
+    elif url == "MOCK":
+        print("wkhtmltopdf 0.12.5 (mock)")
+        return
+
     parts = []
 
     def add_option(option):

tests/kwkhtmltopdf_test.py

@@ -21,7 +21,8 @@ def _wkhtmltopdf_bin():
 
 
 class Client:
-    def __init__(self, cmd):
+    def __init__(self, cmd, env):
+        self.env = env
         self.cmd = cmd
         self.version = self._get_version()
 
@@ -32,12 +33,15 @@ def _get_version(self):
             raise RuntimeError("could not find version in {}".format(out))
         return mo.group(1)
 
-    def _run_stdout(self, args, check_return_code=True):
+    def _run_stdout(self, args, check_return_code=True, env_update={}):
+        env = os.environ.copy()
+        env.update(env_update)
         proc = subprocess.Popen(
             self.cmd + args,
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
             universal_newlines=True,
+            env=env,
         )
         out, _ = proc.communicate()
         if check_return_code:
@@ -76,38 +80,53 @@ def _run_expect_file(self, args, expected_pdf_base_name):
 )
 def client(request):
     if request.param == "native":
-        yield Client([_wkhtmltopdf_bin()])
+        yield Client([_wkhtmltopdf_bin()],
+                     request.param)
     elif request.param == "client_test_py":
         # run the client with same python as test suite
         yield Client(
-            [os.path.join(HERE, "..", "client", "python", "kwkhtmltopdf_client.py")]
+            [os.path.join(HERE, "..", "client", "python", "kwkhtmltopdf_client.py")],
+            request.param
         )
     elif request.param == "client_sys_py2":
         # run the client with the system python2
         yield Client(
             [
                 "/usr/bin/python2",
                 os.path.join(HERE, "..", "client", "python", "kwkhtmltopdf_client.py"),
-            ]
+            ],
+            request.param
         )
     elif request.param == "client_sys_py3":
         # run the client with the system python2
         yield Client(
             [
                 "/usr/bin/python3",
                 os.path.join(HERE, "..", "client", "python", "kwkhtmltopdf_client.py"),
-            ]
+            ],
+            request.param
         )
     elif request.param == "client_go":
         yield Client(
             [
                 "go",
                 "run",
                 os.path.join(HERE, "..", "client", "go", "kwkhtmltopdf_client.go"),
-            ]
+            ],
+            request.param
         )
 
 
+def test_server_url_not_set(client):
+    if client.env == "native":
+        pytest.skip("not relevant for native wkhtmltopdf")
+
+    out = client._run_stdout([],
+                             check_return_code=False,
+                             env_update={'KWKHTMLTOPDF_SERVER_URL': ''})
+    assert re.search(r"KWKHTMLTOPDF_SERVER_URL not set", out)
+
+
 def test_noargs(client):
     out = client._run_stdout([], check_return_code=False)
     assert "Synopsis:" in out
@@ -131,6 +150,15 @@ def test_version(client):
     assert re.search(r"wkhtmltopdf [\d\.]+ ", out)
 
 
+def test_version_mock(client):
+    if client.env == "native":
+        pytest.skip("not relevant for native wkhtmltopdf")
+
+    out = client._run_stdout(["--version"],
+                             env_update={'KWKHTMLTOPDF_SERVER_URL': 'MOCK'})
+    assert re.search(r"wkhtmltopdf [\d\.]+ \(mock\)", out)
+
+
 def test_1(client, tmp_path):
     client._run_expect_file(["test1.html", tmp_path / "o.pdf"], "test1")