implement support for running interactive commands with run_shell_cmd

easybuild/tools/run.py

@@ -36,6 +36,7 @@
 * Ward Poelmans (Ghent University)
 """
 import contextlib
+import fcntl
 import functools
 import inspect
 import os
@@ -201,11 +202,66 @@ def fileprefix_from_cmd(cmd, allowed_chars=False):
     return ''.join([c for c in cmd if c in allowed_chars])
 
 
+def _answer_question(stdout, proc, qa_patterns, qa_wait_patterns):
+    """
+    Private helper function to try and answer questions raised in interactive shell commands.
+    """
+    match_found = False
+
+    for question, answers in qa_patterns:
+        # allow extra whitespace at the end
+        question += r'[\s\n]*$'
+        regex = re.compile(question.encode())
+        res = regex.search(stdout)
+        if res:
+            _log.debug(f"Found match for question pattern '{question}' at end of stdout: {stdout[:1000]}")
+            # if answer is specified as a list, we take the first item as current answer,
+            # and add it to the back of the list (so we cycle through answers)
+            if isinstance(answers, list):
+                answer = answers.pop(0)
+                answers.append(answer)
+            elif isinstance(answers, str):
+                answer = answers
+            else:
+                raise EasyBuildError(f"Unknown type of answers encountered: {answers}")
+
+            # answer may need to be completed via pattern extracted from question
+            _log.debug(f"Raw answer for question pattern '{question}': {answer}")
+            answer = answer % {k: v.decode() for (k, v) in res.groupdict().items()}
+            answer += '\n'
+            _log.info(f"Found match for question pattern '{question}', replying with: {answer}")
+
+            try:
+                os.write(proc.stdin.fileno(), answer.encode())
+            except OSError as err:
+                raise EasyBuildError("Failed to answer question raised by interactive command: %s", err)
+
+            match_found = True
+            break
+    else:
+        _log.info("No match found for question patterns, considering question wait patterns")
+        # if no match was found among question patterns,
+        # take into account patterns for non-questions (qa_wait_patterns)
+        for pattern in qa_wait_patterns:
+            # allow extra whitespace at the end
+            pattern += r'[\s\n]*$'
+            regex = re.compile(pattern.encode())
+            if regex.search(stdout):
+                _log.info(f"Found match for wait pattern '{pattern}'")
+                _log.debug(f"Found match for wait pattern '{pattern}' at end of stdout: {stdout[:1000]}")
+                match_found = True
+                break
+        else:
+            _log.info("No match found for question wait patterns")
+
+    return match_found
+
+
 @run_shell_cmd_cache
 def run_shell_cmd(cmd, fail_on_error=True, split_stderr=False, stdin=None, env=None,
                   hidden=False, in_dry_run=False, verbose_dry_run=False, work_dir=None, use_bash=True,
                   output_file=True, stream_output=None, asynchronous=False, task_id=None, with_hooks=True,
-                  qa_patterns=None, qa_wait_patterns=None):
+                  qa_patterns=None, qa_wait_patterns=None, qa_timeout=100):
     """
     Run specified (interactive) shell command, and capture output + exit code.
 
@@ -226,6 +282,8 @@ def run_shell_cmd(cmd, fail_on_error=True, split_stderr=False, stdin=None, env=N
     :param qa_patterns: list of 2-tuples with patterns for questions + corresponding answers
     :param qa_wait_patterns: list of 2-tuples with patterns for non-questions
                              and number of iterations to allow these patterns to match with end out command output
+    :param qa_timeout: amount of seconds to wait until more output is produced when there is no matching question
+
     :return: Named tuple with:
     - output: command output, stdout+stderr combined if split_stderr is disabled, only stdout otherwise
     - exit_code: exit code of command (integer)
@@ -244,9 +302,13 @@ def to_cmd_str(cmd):
 
         return cmd_str
 
-    # temporarily raise a NotImplementedError until all options are implemented
-    if qa_patterns or qa_wait_patterns:
-        raise NotImplementedError
+    # make sure that qa_patterns is a list of 2-tuples (not a dict, or something else)
+    if qa_patterns:
+        if not isinstance(qa_patterns, list) or any(not isinstance(x, tuple) or len(x) != 2 for x in qa_patterns):
+            raise EasyBuildError("qa_patterns passed to run_shell_cmd should be a list of 2-tuples!")
+
+    if qa_wait_patterns is None:
+        qa_wait_patterns = []
 
     if work_dir is None:
         work_dir = os.getcwd()
@@ -279,11 +341,14 @@ def to_cmd_str(cmd):
     else:
         cmd_out_fp, cmd_err_fp = None, None
 
+    interactive = bool(qa_patterns)
+    interactive_msg = 'interactive ' if interactive else ''
+
     # early exit in 'dry run' mode, after printing the command that would be run (unless 'hidden' is enabled)
     if not in_dry_run and build_option('extended_dry_run'):
         if not hidden or verbose_dry_run:
             silent = build_option('silent')
-            msg = f"  running shell command \"{cmd_str}\"\n"
+            msg = f"  running {interactive_msg}shell command \"{cmd_str}\"\n"
             msg += f"  (in {work_dir})"
             dry_run_msg(msg, silent=silent)
 
@@ -292,7 +357,7 @@ def to_cmd_str(cmd):
 
     start_time = datetime.now()
     if not hidden:
-        _cmd_trace_msg(cmd_str, start_time, work_dir, stdin, cmd_out_fp, cmd_err_fp, thread_id)
+        _cmd_trace_msg(cmd_str, start_time, work_dir, stdin, cmd_out_fp, cmd_err_fp, thread_id, interactive=interactive)
 
     if stream_output:
         print_msg(f"(streaming) output for command '{cmd_str}':")
@@ -309,15 +374,19 @@ def to_cmd_str(cmd):
 
     if with_hooks:
         hooks = load_hooks(build_option('hooks'))
-        hook_res = run_hook(RUN_SHELL_CMD, hooks, pre_step_hook=True, args=[cmd], kwargs={'work_dir': work_dir})
+        kwargs = {
+            'interactive': interactive,
+            'work_dir': work_dir,
+        }
+        hook_res = run_hook(RUN_SHELL_CMD, hooks, pre_step_hook=True, args=[cmd], kwargs=kwargs)
         if hook_res:
             cmd, old_cmd = hook_res, cmd
             cmd_str = to_cmd_str(cmd)
             _log.info("Command to run was changed by pre-%s hook: '%s' (was: '%s')", RUN_SHELL_CMD, cmd, old_cmd)
 
     stderr = subprocess.PIPE if split_stderr else subprocess.STDOUT
 
-    log_msg = f"Running shell command '{cmd_str}' in {work_dir}"
+    log_msg = f"Running {interactive_msg}shell command '{cmd_str}' in {work_dir}"
     if thread_id:
         log_msg += f" (via thread with ID {thread_id})"
     _log.info(log_msg)
@@ -329,23 +398,62 @@ def to_cmd_str(cmd):
     if stdin:
         stdin = stdin.encode()
 
-    if stream_output:
+    if stream_output or qa_patterns:
+
+        if qa_patterns:
+            # make stdout, stderr, stdin non-blocking files
+            channels = [proc.stdout, proc.stdin]
+            if split_stderr:
+                channels += proc.stderr
+            for channel in channels:
+                fd = channel.fileno()
+                flags = fcntl.fcntl(fd, fcntl.F_GETFL)
+                fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK)
+
         if stdin:
             proc.stdin.write(stdin)
 
         exit_code = None
         stdout, stderr = b'', b''
+        check_interval_secs = 0.1
+        time_no_match = 0
 
+        # collect output piece-wise, while checking for questions to answer (if qa_patterns is provided)
         while exit_code is None:
-            exit_code = proc.poll()
 
             # use small read size (128 bytes) when streaming output, to make it stream more fluently
             # -1 means reading until EOF
             read_size = 128 if exit_code is None else -1
 
-            stdout += proc.stdout.read(read_size)
+            more_stdout = proc.stdout.read1(read_size) or b''
+            stdout += more_stdout
+
+            # note: we assume that there won't be any questions in stderr output
             if split_stderr:
-                stderr += proc.stderr.read(read_size)
+                stderr += proc.stderr.read1(read_size) or b''
+
+            if qa_patterns:
+                if _answer_question(stdout, proc, qa_patterns, qa_wait_patterns):
+                    time_no_match = 0
+                else:
+                    _log.debug(f"No match found in question/wait patterns at end of stdout: {stdout[:1000]}")
+                    # this will only run if the for loop above was *not* stopped by the break statement
+                    time_no_match += check_interval_secs
+                    if time_no_match > qa_timeout:
+                        error_msg = "No matching questions found for current command output, "
+                        error_msg += f"giving up after {qa_timeout} seconds!"
+                        raise EasyBuildError(error_msg)
+                    else:
+                        _log.debug(f"{time_no_match:0.1f} seconds without match in output of interactive shell command")
+
+            time.sleep(check_interval_secs)
+
+            exit_code = proc.poll()
+
+        # collect last bit of output once processed has exited
+        stdout += proc.stdout.read()
+        if split_stderr:
+            stderr += proc.stderr.read()
     else:
         (stdout, stderr) = proc.communicate(input=stdin)
 
@@ -385,6 +493,7 @@ def to_cmd_str(cmd):
     if with_hooks:
         run_hook_kwargs = {
             'exit_code': res.exit_code,
+            'interactive': interactive,
             'output': res.output,
             'stderr': res.stderr,
             'work_dir': res.work_dir,
@@ -398,7 +507,7 @@ def to_cmd_str(cmd):
     return res
 
 
-def _cmd_trace_msg(cmd, start_time, work_dir, stdin, cmd_out_fp, cmd_err_fp, thread_id):
+def _cmd_trace_msg(cmd, start_time, work_dir, stdin, cmd_out_fp, cmd_err_fp, thread_id, interactive=False):
     """
     Helper function to construct and print trace message for command being run
 
@@ -409,13 +518,15 @@ def _cmd_trace_msg(cmd, start_time, work_dir, stdin, cmd_out_fp, cmd_err_fp, thr
     :param cmd_out_fp: path to output file for command
     :param cmd_err_fp: path to errors/warnings output file for command
     :param thread_id: thread ID (None when not running shell command asynchronously)
+    :param interactive: boolean indicating whether it is an interactive command, or not
     """
     start_time = start_time.strftime('%Y-%m-%d %H:%M:%S')
 
+    interactive = 'interactive ' if interactive else ''
     if thread_id:
-        run_cmd_msg = f"running shell command (asynchronously, thread ID: {thread_id}):"
+        run_cmd_msg = f"running {interactive}shell command (asynchronously, thread ID: {thread_id}):"
     else:
-        run_cmd_msg = "running shell command:"
+        run_cmd_msg = f"running {interactive}shell command:"
 
     lines = [
         run_cmd_msg,