调用BashOperator时出错：Bash命令失败

Question

以下是我的dag文件和bash操作员任务：

my_dag = { 
dag_id = 'my_dag',
start_date = datetime(year=2017, month=3, day=28),
schedule_interval='01***',
}

my_bash_task = BashOperator(
task_id="my_bash_task",
bash_command=bash_command,
dag=my_dag)

bash_command = "/home/jak/my_projects/workflow_env/repo_workflow/db_backup_bash.sh ""

在这个answer之后，我甚至在bash文件后面留了一个空格，以避免TemplateNotFound错误。但在运行此任务时出现了以下错误：airlow.exceptions.airlowexception:Bash命令失败。

bash_命令文件的内容是：

#!/bin/bash
DATABASE=db_name
FILE=$DATABASE-`date +%F-%H%M%S`.backup
export PGPASSWORD=password
pg_dump -h localhost -p 5432 -U developer -F c -b -v -f ~/Dropbox/database_backup/location/$FILE db_name
unset PGPASSWORD

但是，不是将bash_命令指向bash文件，而是用多行字符串编写命令：

bash_command = """
DATABASE=db_name
FILE=$DATABASE-`date +%F-%H%M%S`.backup
export PGPASSWORD=password
pg_dump -h localhost -p 5432 -U developer -F c -b -v -f ~/Dropbox/database_backup/location/$FILE db_name
unset PGPASSWORD
"""

因此，我假设错误不是因为bash命令。 我甚至试着换掉了！/用#在bash文件中bin/bash！/bin/sh，也没用。

我从终结者那里运行了sh db_back_up_bash.sh，运行得很好。

更新实际代码：

bash_file_location_to_backup_db = '{{"/home/jak/my_projects/workflow_env/repo_workflow/db_backup_bash.sh"}}'
# bash_file_location_to_backup_db = "/home/jak/my_projects/workflow_env/repo_workflow/db_backup_bash.sh "
bash_command = """
DATABASE=ksaprice_scraping
FILE=$DATABASE-`date +%F-%H%M%S`.backup
export PGPASSWORD=password
pg_dump -h localhost -p 5432 -U developer -F c -b -v -f ~/Dropbox/database_backup/ksaprice/$FILE ksaprice_scraping
unset PGPASSWORD
"""

backup_scraped_db_in_dropbox_task = BashOperator(
    task_id="backup_scraped_db_in_dropbox_task",
    # bash_command=bash_command,# this works fine
    bash_command=bash_file_location_to_backup_db,#this give error :airflow.exceptions.AirflowException: Bash command failed
    dag=dag_crawl
)

错误跟踪：

[2017-04-11 20:02:14,905] {bash_operator.py:90} INFO - Output:
2017-04-11 20:02:14,905 | INFO| root : Output:
[2017-04-11 20:02:14,906] {bash_operator.py:94} INFO - /tmp/airflowtmp7FffJ2/backup_scraped_db_in_dropbox_taskQ6IVxm: line 1: /home/jak/my_projects/workflow_env/repo_workflow/db_backup_bash.sh: Permission denied
2017-04-11 20:02:14,906 | INFO| root : /tmp/airflowtmp7FffJ2/backup_scraped_db_in_dropbox_taskQ6IVxm: line 1: /home/jak/my_projects/workflow_env/repo_workflow/db_backup_bash.sh: Permission denied
[2017-04-11 20:02:14,906] {bash_operator.py:97} INFO - Command exited with return code 126
2017-04-11 20:02:14,906 | INFO| root : Command exited with return code 126
[2017-04-11 20:02:14,906] {models.py:1417} ERROR - Bash command failed
Traceback (most recent call last):
  File "/home/jak/my_projects/workflow_env/local/lib/python2.7/site-packages/airflow/models.py", line 1374, in run
    result = task_copy.execute(context=context)
  File "/home/jak/my_projects/workflow_env/local/lib/python2.7/site-packages/airflow/operators/bash_operator.py", line 100, in execute
    raise AirflowException("Bash command failed")
AirflowException: Bash command failed
2017-04-11 20:02:14,906 | ERROR| root : Bash command failed
Traceback (most recent call last):
  File "/home/jak/my_projects/workflow_env/local/lib/python2.7/site-packages/airflow/models.py", line 1374, in run
    result = task_copy.execute(context=context)
  File "/home/jak/my_projects/workflow_env/local/lib/python2.7/site-packages/airflow/operators/bash_operator.py", line 100, in execute
    raise AirflowException("Bash command failed")
AirflowException: Bash command failed
[2017-04-11 20:02:14,907] {models.py:1441} INFO - Marking task as FAILED.
2017-04-11 20:02:14,907 | INFO| root : Marking task as FAILED.
[2017-04-11 20:02:14,947] {models.py:1462} ERROR - Bash command failed
2017-04-11 20:02:14,947 | ERROR| root : Bash command failed
Traceback (most recent call last):
  File "/home/jak/my_projects/workflow_env/bin/airflow", line 28, in <module>
    args.func(args)
  File "/home/jak/my_projects/workflow_env/local/lib/python2.7/site-packages/airflow/bin/cli.py", line 585, in test
    ti.run(ignore_task_deps=True, ignore_ti_state=True, test_mode=True)
  File "/home/jak/my_projects/workflow_env/local/lib/python2.7/site-packages/airflow/utils/db.py", line 53, in wrapper
    result = func(*args, **kwargs)
  File "/home/jak/my_projects/workflow_env/local/lib/python2.7/site-packages/airflow/models.py", line 1374, in run
    result = task_copy.execute(context=context)
  File "/home/jak/my_projects/workflow_env/local/lib/python2.7/site-packages/airflow/operators/bash_operator.py", line 100, in execute
    raise AirflowException("Bash command failed")
airflow.exceptions.AirflowException: Bash command faile