If no stdout/stderr requested tell Kubernetes not to send it

kr8s/_exec.py

@@ -32,13 +32,15 @@ def __init__(
         stdout: Union(str | BinaryIO) = None,
         stderr: Union(str | BinaryIO) = None,
         check: bool = True,
+        capture_output: bool = True,
     ) -> None:
         self._resource = resource
         self._container = container
 
         self._stdin = stdin
         self._stdout = stdout
         self._stderr = stderr
+        self._capture_output = capture_output
 
         self.args = command
         self.stdout = b""
@@ -57,8 +59,8 @@ async def run(
             params={
                 "command": self.args,
                 "container": self._container or self._resource.spec.containers[0].name,
-                "stdout": "true",
-                "stderr": "true",
+                "stdout": "true" if self._stdout or self._capture_output else "false",
+                "stderr": "true" if self._stderr or self._capture_output else "false",
                 "stdin": "true" if self._stdin is not None else "false",
             },
         ) as ws:
@@ -75,11 +77,13 @@ async def run(
                     channel, message = int(message.data[0]), message.data[1:]
                     if message:
                         if channel == STDOUT_CHANNEL:
-                            self.stdout += message
+                            if self._capture_output:
+                                self.stdout += message
                             if self._stdout:
                                 self._stdout.write(message)
                         elif channel == STDERR_CHANNEL:
-                            self.stderr += message
+                            if self._capture_output:
+                                self.stderr += message
                             if self._stderr:
                                 self._stderr.write(message)
                         elif channel == ERROR_CHANNEL:

kr8s/_objects.py

@@ -776,10 +776,11 @@ async def _exec(
         command: List[str],
         *,
         container: str = None,
-        stdin: Union(str | BinaryIO) = None,
-        stdout: Union(str | BinaryIO) = None,
-        stderr: Union(str | BinaryIO) = None,
+        stdin: Union(str | bytes | BinaryIO) = None,
+        stdout: BinaryIO = None,
+        stderr: BinaryIO = None,
         check: bool = True,
+        capture_output: bool = True,
     ):
         ex = Exec(
             self,
@@ -789,6 +790,7 @@ async def _exec(
             stderr=stderr,
             stdin=stdin,
             check=check,
+            capture_output=capture_output,
         )
         async with ex.run() as process:
             await process.wait()
@@ -799,20 +801,22 @@ async def exec(
         command: List[str],
         *,
         container: str = None,
-        stdin: Union(str | BinaryIO) = None,
-        stdout: Union(str | BinaryIO) = None,
-        stderr: Union(str | BinaryIO) = None,
+        stdin: Union(str | bytes | BinaryIO) = None,
+        stdout: BinaryIO = None,
+        stderr: BinaryIO = None,
         check: bool = True,
+        capture_output: bool = True,
     ):
         """Run a command in a container and wait until it completes.
 
         Args:
             command: Command to execute.
             container: Container to execute the command in.
-            stdin: If True, pass stdin to the container.
-            stdout: If True, capture stdout from the container.
-            stderr: If True, capture stderr from the container.
+            stdin: If set, read stdin to the container.
+            stdout: If set, write stdout to the provided writable stream object.
+            stderr: If set, write stderr to the provided writable stream object.
             check: If True, raise an exception if the command fails.
+            capture_output: If True, store stdout and stderr from the container in an attribute.
         """
         return await self._exec(
             command,
@@ -821,6 +825,7 @@ async def exec(
             stdout=stdout,
             stderr=stderr,
             check=check,
+            capture_output=capture_output,
         )
 
 

kr8s/tests/test_objects.py

@@ -744,9 +744,10 @@ async def test_pod_exec_error(ubuntu_pod):
 
 async def test_pod_exec_to_file(ubuntu_pod):
     with tempfile.TemporaryFile(mode="w+b") as tmp:
-        await ubuntu_pod.exec(["date"], stdout=tmp)
+        exc = await ubuntu_pod.exec(["date"], stdout=tmp, capture_output=False)
         tmp.seek(0)
         assert str(datetime.datetime.now().year) in tmp.read().decode()
+        assert exc.stdout == b""
 
     with tempfile.TemporaryFile(mode="w+b") as tmp:
         with pytest.raises(ExecError):