feature: add 'exec' returning a process and deprecates 'exec_command'

Author: Fabs

dcos_test_utils/dcos_cli.py

@@ -14,6 +14,7 @@
 import tempfile
 from typing import Optional
 
+import deprecation
 import requests
 
 log = logging.getLogger(__name__)
@@ -92,6 +93,67 @@ def clear_cli_dir():
         if os.path.exists(path):
             shutil.rmtree(path)
 
+    def exec(self, cmd: str, stdin=None, check=True) -> subprocess.CompletedProcess:
+        """Execute CLI command and processes result.
+
+        This method expects that process won't block.
+
+        :param cmd: Program and arguments
+        :type cmd: str
+        :param stdin: File to use for stdin
+        :param check: Does it check for raised errors
+        :type stdin: typing.optional[File]
+        :returns: A tuple with stdout and stderr
+        :rtype: subprocess.CompletedProcess
+
+        :raises subprocess.CalledProcessError: When check=True if the returncode of \
+        cmd is not 0
+        exception description.
+        """
+
+        log.info('CMD: {!r}'.format(cmd))
+
+        # Borrowed from dcos-e2e
+        # https://github.com/dcos/dcos-e2e/blob/8d4916780ade8caf41dae376fdf47f4253eb52c7/src/dcos_e2e/_common.py#L46-L59
+        def safe_decode(output_bytes: bytes) -> str:
+            """
+            Decode a bytestring to Unicode with a safe fallback.
+            """
+            try:
+                return output_bytes.decode(
+                    encoding='utf-8',
+                    errors='strict')
+            except UnicodeDecodeError:
+                return output_bytes.decode(
+                    encoding='ascii',
+                    errors='backslashreplace')
+
+        try:
+            process = subprocess.run(
+                cmd,
+                stdin=stdin,
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE,
+                env=self.env,
+                check=check)
+        except subprocess.CalledProcessError as e:
+            stderr = safe_decode(e.stderr)
+            log.error('STDERR: {}'.format(stderr))
+
+            stdout = safe_decode(e.stdout)
+            log.error('STDOUT: {}'.format(stdout))
+
+            raise
+
+        stdout = safe_decode(process.stdout)
+        log.info('STDOUT: {}'.format(stdout))
+
+        stderr = safe_decode(process.stdout)
+        log.info('STDERR: {}'.format(stderr))
+
+        return process
+
+    @deprecation.deprecated(details="Deprecated in favor of the `exec` function. DCOS-44823")
     def exec_command(self, cmd: str, stdin=None) -> tuple:
         """Execute CLI command and processes result.
 

requirements.txt

@@ -3,5 +3,6 @@ pytest
 requests
 retrying
 tox
+deprecation
 
 sphinx

tests/test_dcos_cli.py

@@ -1,9 +1,11 @@
-import pytest
 import subprocess
 
+import deprecation
+import pytest
 from dcos_test_utils import dcos_cli
 
 
+@deprecation.deprecated(details="Deprecated in favor of the `exec` function. DCOS-44823")
 def test_exec_command(caplog):
     cli = dcos_cli.DcosCli('')
     stdout, stderr = cli.exec_command(
@@ -16,9 +18,46 @@ def test_exec_command(caplog):
     assert any(rec.message.startswith('STDERR:') for rec in caplog.records)
 
 
+@deprecation.deprecated(details="Deprecated in favor of the `exec` function. DCOS-44823")
 def test_exec_command_fail(caplog):
     cli = dcos_cli.DcosCli('')
     with pytest.raises(subprocess.CalledProcessError):
         cli.exec_command(['/bin/sh', '-c', 'does-not-exist'])
     assert any(rec.message.startswith('CMD:') for rec in caplog.records)
     assert any(rec.message.startswith('STDERR:') for rec in caplog.records)
+
+
+def test_exec(caplog):
+    cli = dcos_cli.DcosCli('')
+    process = cli.exec(
+        ['/bin/sh', '-c', 'echo "hello, world!"']
+    )
+    assert process.stdout == b'hello, world!\n'
+    assert process.stderr == b''
+    assert process.returncode == 0
+    assert any(rec.message.startswith('CMD:') for rec in caplog.records)
+    assert any(rec.message.startswith('STDOUT:') for rec in caplog.records)
+    assert any(rec.message.startswith('STDERR:') for rec in caplog.records)
+
+
+def test_exec_fail(caplog):
+    cli = dcos_cli.DcosCli('')
+    with pytest.raises(subprocess.CalledProcessError):
+        cli.exec(['/bin/sh', '-c', 'does-not-exist'])
+    assert any(rec.message.startswith('CMD:') for rec in caplog.records)
+    assert any(rec.message.startswith('STDERR:') for rec in caplog.records)
+    assert any(rec.message.startswith('STDOUT:') for rec in caplog.records)
+
+
+def test_exec_fail_without_check(caplog):
+    cli = dcos_cli.DcosCli('')
+    process = cli.exec(
+        ['/bin/sh', '-c', 'does-not-exist'],
+        check=False
+    )
+    assert process.stdout == b''
+    assert b'does-not-exist' in process.stderr
+    assert process.returncode == 127
+    assert any(rec.message.startswith('CMD:') for rec in caplog.records)
+    assert any(rec.message.startswith('STDOUT:') for rec in caplog.records)
+    assert any(rec.message.startswith('STDERR:') for rec in caplog.records)