Docker上的PostgreSQL：如何在“plpython3u”下安装和运行python依赖项？

Question

使用Dockerfile我可以完美地运行plpython3u

FROM postgres:11.3

RUN apt-get update && apt-get install -y postgresql-plpython3-11

CREATE OR REPLACE FUNCTION return_version()
  RETURNS VARCHAR
AS $$
    import sys
    return sys.version
$$ LANGUAGE plpython3u;

3.5.3（默认，2020年7月9日13:00:10）[GCC 6.3.0 20170516]`

但我不能使用依赖项，例如请求

[38000] ERROR: ImportError: No module named 'requests' 
Where: Traceback (most recent call last): PL/Python function "return_version", line 3, 
in <module> import requests PL/Python function "return_version"

第一次尝试执行呼叫

CREATE OR REPLACE FUNCTION return_pip()
RETURNS VARCHAR AS $$
from subprocess import call
return call(["pip", "install", "requests"])
$$ LANGUAGE plpython3u STABLE ;

没有希望

[38000] ERROR: FileNotFoundError: [Errno 2] No such file or directory: 'pip' Where: Traceback (most recent call last): PL/Python function "return_ls", line 3, in <module> return call(["pip", "install", "requuest"]) PL/Python function "return_ls", line 246, in c ...

第二次尝试

CREATE OR REPLACE FUNCTION return_version()
  RETURNS VARCHAR
AS $$
    import sys
    from subprocess import call
    return call(["pip3", "install", "requests"])

    import requests
    res = requests.get('https://google.com')
    print(res.text)
    return res.text
$$ LANGUAGE plpython3u;

得到错误

SELECT return_version()
[2020-09-29 10:59:44] [38000] ERROR: FileNotFoundError: [Errno 2] No such file or directory: 'pip3'
[2020-09-29 10:59:44] Where: Traceback (most recent call last):
[2020-09-29 10:59:44] PL/Python function "return_version", line 4, in <module>
[2020-09-29 10:59:44] return call(["pip3", "install", "requests"])
[2020-09-29 10:59:44] PL/Python function "return_version", line 246, in call
[2020-09-29 10:59:44] PL/Python function "return_version", line 675, in __init__
[2020-09-29 10:59:44] PL/Python function "return_version", line 1281, in _execute_child
[2020-09-29 10:59:44] PL/Python function "return_version"

我遇到一个相似的人问同样的问题，但没有回答

问题：
如何在plpython3u下安装和运行python依赖项？

Answer 1

感谢@AdrianKlaver的回答

跟着这个。我可以得到响应

1. I pick this answer to be my image
2. Execute CREATE EXTENSION plpython3u; in SQL shell
3. Run pip3 install requests In OS(aka container)
4. create function

   CREATE OR REPLACE FUNCTION return_version()
      RETURNS VARCHAR
   AS $$
    import requests
    res = requests.get('https://google.com')
    return str(res.text)
   $$ LANGUAGE plpython3u;