GHI-#11 Implement the core plugin "Shell(snowsaw.Plugin)"

snowsaw/plugins/shell.py

@@ -0,0 +1,61 @@
+import os
+import subprocess
+import snowsaw
+
+
+class Shell(snowsaw.Plugin):
+ """
+ Core plugin to run arbitrary shell commands.
+ """
+ _directive = "shell"
+
+ def can_handle(self, directive):
+ return directive == self._directive
+
+ def handle(self, directive, data):
+ if directive != self._directive:
+ raise ValueError("Core plugin \"Shell\" cannot handle the directive \"{}\"".format(directive))
+ return self._process_commands(data)
+
+ def _process_commands(self, data):
+ """
+ Processes specified commands.
+
+ :param data: The commands to process
+ :return: True if the commands have been processed successfully, False otherwise
+ """
+ success = True
+ defaults = self._context.defaults().get("shell", {})
+ with open(os.devnull, "w") as devnull:
+ for item in data:
+ stdin = stdout = stderr = devnull
+ if isinstance(item, dict):
+ cmd = item["command"]
+ msg = item.get("description", None)
+ if item.get("stdin", defaults.get("stdin", False)) is True:
+ stdin = None
+ if item.get("stdout", defaults.get("stdout", False)) is True:
+ stdout = None
+ if item.get("stderr", defaults.get("stderr", False)) is True:
+ stderr = None
+ elif isinstance(item, list):
+ cmd = item[0]
+ msg = item[1] if len(item) > 1 else None
+ else:
+ cmd = item
+ msg = None
+ if msg is None:
+ self._log.lowinfo(cmd)
+ else:
+ self._log.lowinfo('{} [{}]'.format(msg, cmd))
+ executable = os.environ.get("SHELL")
+ ret = subprocess.call(cmd, shell=True, stdin=stdin, stdout=stdout, stderr=stderr, cwd=self._context.snowblock_dir(),
+ executable=executable)
+ if ret != 0:
+ success = False
+ self._log.warning("Command [{}] failed".format(cmd))
+ if success:
+ self._log.info("=> All commands have been executed")
+ else:
+ self._log.error("Some commands were not successfully executed")
+ return success