[BUG] localfs cache not working properly with rest_cherrypy api

[serhatcetinkaya]

Description
I am trying to cache grains of a minion and read it over HTTP API. It works as expected when I try with CLI command, but I kepp getting same error with HTTP API.

Setup
We run salt master in a docker container with following config:

/ # more /etc/salt/master.d/api.conf
rest_cherrypy:
  disable_ssl: True
  webhook_url: /hook
  host: 127.0.0.1
  port: 8000
  webhook_disable_auth: True

/ # more /etc/salt/master.d/master.conf
cachedir: "/var/cache/salt"
keep_jobs: 3
gather_job_timeout: 30
timeout: 30
con_cache: true
external_auth:
  pam:
    root:
      - '.*'
      - '@runner'
      - '@wheel'
  sharedsecret:
    saltapi:
      - '.*'
      - '@runner'
      - '@wheel'
      - '@jobs'

sharedsecret: ***

state_top: "top.sls"
state_verbose: false

file_roots:
  base:
    - /srv/salt-repo/salt/dev

fileserver_backend:
  - roots

pillar_roots:
  base:
    - /srv/salt-repo/pillar/dev

peer_run:
  .*:
      - vault.generate_token
include:
  - /config/secrets.conf

Steps to Reproduce the behavior

1. Create a minion with some grains
2. Run cache.grains function targeting the new minion to cache grains
3. Verify data is cached by checking cachedir on localfs (in my case it is /var/cache/salt)
4. Run salt-run cache.fetch command to fetch cached grains (in my case salt-run cache.fetch minions/temp-0572/data grains temp-0572 being the minion id)
5. Make a HTTP request for the same function:

curl -XPOST http://localhost:8000 -d '{"client": "runner", "fun": "cache.fetch", "bank": "minions/temp-0572/data", "key": "grains", "cachedir": "/var/cache/salt"}'

Then see the request failed with following error:

Passed invalid arguments: fetch() missing 1 required positional argument: 'key'

Usage:

    Fetch data from a salt.cache bank.

    CLI Example:

    .. code-block:: bash

        salt-run cache.fetch
cloud/active/ec2/myec2 myminion cachedir=/var/cache/salt/

Expected behavior
Have the same successful result as step 4 on step 5.

Versions Report

salt --versions-report

(Provided by running salt --versions-report. Please also mention any differences in master/minion versions.)

Salt Version:
          Salt: 3003

Dependency Versions:
          cffi: 1.14.4
      cherrypy: unknown
      dateutil: 2.8.1
     docker-py: Not Installed
         gitdb: Not Installed
     gitpython: Not Installed
        Jinja2: 2.10.1
       libgit2: 1.1.0
      M2Crypto: Not Installed
          Mako: Not Installed
       msgpack: 1.0.2
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     pycparser: 2.17
      pycrypto: Not Installed
  pycryptodome: 3.9.8
        pygit2: 1.6.1
        Python: 3.7.12 (default, Sep  8 2021, 02:04:31)
  python-gnupg: 0.4.4
        PyYAML: 5.3.1
         PyZMQ: 18.0.1
         smmap: Not Installed
       timelib: 0.2.4
       Tornado: 4.5.3
           ZMQ: 4.3.1

System Versions:
          dist: alpine 3.13.6
        locale: UTF-8
       machine: x86_64
       release: 5.4.129-63.229.amzn2.x86_64
        system: Linux
       version: Alpine Linux 3.13.6

Additional context
I can use HTTP API without any problem except for this case. I tried different payloads with the request, it didn't matter I always got the same response:

'{"client": "runner", "fun": "cache.fetch", "bank": "minions/temp-0572/data", "key": "grains", "cachedir": "/var/cache/salt"}'
'{"client": "runner", "fun": "cache.fetch", "bank": "minions/temp-0572/data", "key": "grains"}'
'{"client": "runner", "fun": "cache.fetch", "key": "grains", "bank": "minions/temp-0572/data"}'
[...]

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[serhatcetinkaya]

did anyone take a look at this ?