Merge in latest from datadog/dd-trace-py (#1)

ddtrace/commands/ddtrace_run.py

@@ -0,0 +1,82 @@
+#!/usr/bin/env python
+from distutils import spawn
+import os
+import sys
+import logging
+
+debug = os.environ.get('DATADOG_TRACE_DEBUG')
+if debug and debug.lower() == 'true':
+    logging.basicConfig(level=logging.DEBUG)
+
+# Do not use `ddtrace.internal.logger.get_logger` here
+# DEV: It isn't really necessary to use `DDLogger` here so we want to
+#        defer importing `ddtrace` until we actually need it.
+#      As well, no actual rate limiting would apply here since we only
+#        have a few logged lines
+log = logging.getLogger(__name__)
+
+USAGE = """
+Execute the given Python program after configuring it to emit Datadog traces.
+Append command line arguments to your program as usual.
+
+Usage: [ENV_VARS] ddtrace-run <my_program>
+
+Available environment variables:
+
+    DATADOG_ENV : override an application's environment (no default)
+    DATADOG_TRACE_ENABLED=true|false : override the value of tracer.enabled (default: true)
+    DATADOG_TRACE_DEBUG=true|false : enabled debug logging (default: false)
+    DATADOG_PATCH_MODULES=module:patch,module:patch... e.g. boto:true,redis:false : override the modules patched for this execution of the program (default: none)
+    DATADOG_TRACE_AGENT_HOSTNAME=localhost: override the address of the trace agent host that the default tracer will attempt to submit to  (default: localhost)
+    DATADOG_TRACE_AGENT_PORT=8126: override the port that the default tracer will submit to (default: 8126)
+    DATADOG_SERVICE_NAME : override the service name to be used for this program (no default)
+                           This value is passed through when setting up middleware for web framework integrations.
+                           (e.g. pylons, flask, django)
+                           For tracing without a web integration, prefer setting the service name in code.
+    DATADOG_PRIORITY_SAMPLING=true|false : (default: false): enables Priority Sampling.
+"""  # noqa: E501
+
+
+def _ddtrace_root():
+    from ddtrace import __file__
+    return os.path.dirname(__file__)
+
+
+def _add_bootstrap_to_pythonpath(bootstrap_dir):
+    """
+    Add our bootstrap directory to the head of $PYTHONPATH to ensure
+    it is loaded before program code
+    """
+    python_path = os.environ.get('PYTHONPATH', '')
+
+    if python_path:
+        new_path = '%s%s%s' % (bootstrap_dir, os.path.pathsep, os.environ['PYTHONPATH'])
+        os.environ['PYTHONPATH'] = new_path
+    else:
+        os.environ['PYTHONPATH'] = bootstrap_dir
+
+
+def main():
+    if len(sys.argv) < 2 or sys.argv[1] == '-h':
+        print(USAGE)
+        return
+
+    log.debug('sys.argv: %s', sys.argv)
+
+    root_dir = _ddtrace_root()
+    log.debug('ddtrace root: %s', root_dir)
+
+    bootstrap_dir = os.path.join(root_dir, 'bootstrap')
+    log.debug('ddtrace bootstrap: %s', bootstrap_dir)
+
+    _add_bootstrap_to_pythonpath(bootstrap_dir)
+    log.debug('PYTHONPATH: %s', os.environ['PYTHONPATH'])
+    log.debug('sys.path: %s', sys.path)
+
+    executable = sys.argv[1]
+
+    # Find the executable path
+    executable = spawn.find_executable(executable)
+    log.debug('program executable: %s', executable)
+
+    os.execl(executable, executable, *sys.argv[2:])