celery 4.1下报kombu.exceptions.EncodeError: Object of type 'bytes' is not JSON serializable 处理方式

#python代码如下

from celery import Celery
import subprocess

app = Celery('tasks',
broker='redis://localhost',
backend='redis://localhost')

@app.task
def add(x,y):
print("running...",x,y)
return x+y

@app.task
def run_cmd(cmd):
cmd_obj=subprocess.Popen(cmd,shell=True,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
return cmd_obj.stdout.read()

[python@qinhan file]$ python
Python 3.6. (default, Jan  , ::)
[GCC 4.8.  (Red Hat 4.8.-)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import task
>>> task.run_cmd('df')    #此条命令不会发送到celery后台
b'Filesystem              1K-blocks    Used Available Use% Mounted on\n/dev/mapper/centos-root   5232640 2481244   2751396  48% /\ndevtmpfs                   490308       0    490308   0% /dev\ntmpfs                      500680       0    500680   0% /dev/shm\ntmpfs                      500680    6968    493712   2% /run\ntmpfs                      500680       0    500680   0% /sys/fs/cgroup\n/dev/mapper/centos-home   2086912   33076   2053836   2% /home\n/dev/mapper/centos-var     975532  633120    342412  65% /var\n/dev/sda1                  508588  126972    381616  25% /boot\ntmpfs                      100136       0    100136   0% /run/user/0\n'
>>> task.run_cmd.delay('df')  #此条命令会发送到celery后台,celery后台报错not JSON serializable
<AsyncResult: 2c671a6b-be73-4f46-8b55-c58f0a05ed2f>
>>> 

#celery后台报错信息如下

Traceback (most recent call last):
File "/usr/local/python3/lib/python3.6/site-packages/celery/app/trace.py", line 434, in trace_task
uuid, retval, task_request, publish_result,
File "/usr/local/python3/lib/python3.6/site-packages/celery/backends/base.py", line 152, in mark_as_done
self.store_result(task_id, result, state, request=request)
File "/usr/local/python3/lib/python3.6/site-packages/celery/backends/base.py", line 309, in store_result
request=request, **kwargs)
File "/usr/local/python3/lib/python3.6/site-packages/celery/backends/base.py", line 652, in _store_result
self.set(self.get_key_for_task(task_id), self.encode(meta))
File "/usr/local/python3/lib/python3.6/site-packages/celery/backends/base.py", line 259, in encode
_, _, payload = self._encode(data)
File "/usr/local/python3/lib/python3.6/site-packages/celery/backends/base.py", line 263, in _encode
return dumps(data, serializer=self.serializer)
File "/usr/local/python3/lib/python3.6/site-packages/kombu/serialization.py", line 221, in dumps
payload = encoder(data)
File "/usr/local/python3/lib/python3.6/contextlib.py", line 99, in __exit__
self.gen.throw(type, value, traceback)
File "/usr/local/python3/lib/python3.6/site-packages/kombu/serialization.py", line 54, in _reraise_errors
reraise(wrapper, wrapper(exc), sys.exc_info()[2])
File "/usr/local/python3/lib/python3.6/site-packages/vine/five.py", line 178, in reraise
raise value.with_traceback(tb)
File "/usr/local/python3/lib/python3.6/site-packages/kombu/serialization.py", line 50, in _reraise_errors
yield
File "/usr/local/python3/lib/python3.6/site-packages/kombu/serialization.py", line 221, in dumps
payload = encoder(data)
File "/usr/local/python3/lib/python3.6/site-packages/kombu/utils/json.py", line 72, in dumps
**dict(default_kwargs, **kwargs))
File "/usr/local/python3/lib/python3.6/json/__init__.py", line 238, in dumps
**kw).encode(obj)
File "/usr/local/python3/lib/python3.6/json/encoder.py", line 199, in encode
chunks = self.iterencode(o, _one_shot=True)
File "/usr/local/python3/lib/python3.6/json/encoder.py", line 257, in iterencode
return _iterencode(o, 0)
File "/usr/local/python3/lib/python3.6/site-packages/kombu/utils/json.py", line 62, in default
return super(JSONEncoder, self).default(o)
File "/usr/local/python3/lib/python3.6/json/encoder.py", line 180, in default
o.__class__.__name__)
kombu.exceptions.EncodeError: Object of type 'bytes' is not JSON serializable

间接处理方法，直接把数据转换为json格式(只是做测试用，可以忽略)

>>> r=b'Filesystem 1K-blocks Used Available Use% Mounted on\n/dev/mapper/centos-root 5232640 2481244 2751396 48% /\ndevtmpfs 490308 0 490308 0% /dev\ntmpfs 500680 0 500680 0% /dev/shm\ntmpfs 500680 6968 493712 2% /run\ntmpfs 500680 0 500680 0% /sys/fs/cgroup\n/dev/mapper/centos-home 2086912 33056 2053856 2% /home\n/dev/mapper/centos-var 975532 633208 342324 65% /var\n/dev/sda1 508588 126972 381616 25% /boot\ntmpfs 100136 0 100136 0% /run/user/0\n'

>>> import json

>>> r.decode()
'Filesystem 1K-blocks Used Available Use% Mounted on\n/dev/mapper/centos-root 5232640 2481244 2751396 48% /\ndevtmpfs 490308 0 490308 0% /dev\ntmpfs 500680 0 500680 0% /dev/shm\ntmpfs 500680 6968 493712 2% /run\ntmpfs 500680 0 500680 0% /sys/fs/cgroup\n/dev/mapper/centos-home 2086912 33056 2053856 2% /home\n/dev/mapper/centos-var 975532 633208 342324 65% /var\n/dev/sda1 508588 126972 381616 25% /boot\ntmpfs 100136 0 100136 0% /run/user/0\n'

>>> json.dumps(r.decode())
'"Filesystem 1K-blocks Used Available Use% Mounted on\\n/dev/mapper/centos-root 5232640 2481244 2751396 48% /\\ndevtmpfs 490308 0 490308 0% /dev\\ntmpfs 500680 0 500680 0% /dev/shm\\ntmpfs 500680 6968 493712 2% /run\\ntmpfs 500680 0 500680 0% /sys/fs/cgroup\\n/dev/mapper/centos-home 2086912 33056 2053856 2% /home\\n/dev/mapper/centos-var 975532 633208 342324 65% /var\\n/dev/sda1 508588 126972 381616 25% /boot\\ntmpfs 100136 0 100136 0% /run/user/0\\n"'

　　

最终解决方法

#修改编码格式为utf-8
from celery import Celery
import subprocess

app = Celery('tasks',
             broker='redis://localhost',
             backend='redis://localhost')

@app.task
def add(x,y):
    print("running...",x,y)
    return x+y

@app.task
def run_cmd(cmd):
        cmd_obj=subprocess.Popen(cmd,shell=True,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
        return cmd_obj.stdout.read().decode("utf-8")

重启celery
celery -A task worker --loglevel=debug

#前端执行python脚本

[python@qinhan file]$ python
Python 3.6.2 (default, Jan 10 2018, 16:15:47)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import task
>>> task.run_cmd.delay('df')
<AsyncResult: b0d9d480-e51d-4304-9128-1b676d70d3fe>
>>> a=task.run_cmd.delay("df -h")

>>> a.get()
'Filesystem Size Used Avail Use% Mounted on\n/dev/mapper/centos-root 5.0G 2.4G 2.7G 48% /\ndevtmpfs 479M 0 479M 0% /dev\ntmpfs 489M 0 489M 0% /dev/shm\ntmpfs 489M 6.9M 483M 2% /run\ntmpfs 489M 0 489M 0% /sys/fs/cgroup\n/dev/mapper/centos-home 2.0G 33M 2.0G 2% /home\n/dev/mapper/centos-var 953M 619M 335M 65% /var\n/dev/sda1 497M 124M 373M 25% /boot\ntmpfs 98M 0 98M 0% /run/user/0\n'
>>>

#后台celery执行成功，不在报错not JSON serializable

[2018-01-12 10:26:27,236: DEBUG/MainProcess] | Worker: Hub.register Pool...
[2018-01-12 10:26:27,237: INFO/MainProcess] celery@qinhan ready.
[2018-01-12 10:26:27,238: DEBUG/MainProcess] basic.qos: prefetch_count->16
[2018-01-12 10:27:06,818: INFO/MainProcess] Received task: task.run_cmd[b0d9d480-e51d-4304-9128-1b676d70d3fe]
[2018-01-12 10:27:06,819: DEBUG/MainProcess] TaskPool: Apply <function _fast_trace_task at 0x7f02b051cd08> (args:('task.run_cmd', 'b0d9d480-e51d-4304-9128-1b676d70d3fe', {'lang': 'py', 'task': 'task.run_cmd', 'id': 'b0d9d480-e51d-4304-9128-1b676d70d3fe', 'eta': None, 'expires': None, 'group': None, 'retries': 0, 'timelimit': [None, None], 'root_id': 'b0d9d480-e51d-4304-9128-1b676d70d3fe', 'parent_id': None, 'argsrepr': "('df',)", 'kwargsrepr': '{}', 'origin': 'gen71158@qinhan', 'reply_to': '61d4cf29-4204-397e-854d-446c648c8b9e', 'correlation_id': 'b0d9d480-e51d-4304-9128-1b676d70d3fe', 'delivery_info': {'exchange': '', 'routing_key': 'celery', 'priority': 0, 'redelivered': None}}, b'[["df"], {}, {"callbacks": null, "errbacks": null, "chain": null, "chord": null}]', 'application/json', 'utf-8') kwargs:{})
[2018-01-12 10:27:06,825: DEBUG/MainProcess] Task accepted: task.run_cmd[b0d9d480-e51d-4304-9128-1b676d70d3fe] pid:71152
[2018-01-12 10:27:06,842: INFO/ForkPoolWorker-1] Task task.run_cmd[b0d9d480-e51d-4304-9128-1b676d70d3fe] succeeded in 0.020323514996562153s: 'Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/centos-root 5232640 2481252 2751388 48% /
devtmpfs 490308 0 490308 0% /dev
tmpfs 500680 0 500680 0% /dev/shm
tmpfs 500680 6968 493712 2% /run
tmpfs 500680 0 500680 0% /sys/fs/cgroup
/dev/mapper/centos-home 2086912 33056 2053856 2% /home
/dev/mapper/centos-var 975532 633120 342412 65% /var
/dev/sda1 508588 126972 381616 25% /boot
tmpfs 100136 0 100136 0% /run/user/0
'