Also support django_prpmetheus wrapped caches

[Natureshadow]

Description

Add the cache backends wrapped by django_prometheus as supported backends.

Rationale

cachalot already explicitly supports django_prometheus' wrappers for database backends. djanfo_prometheus does the same wrapping for cache backends, so they should be supported as well.

[coveralls]

Pull Request Test Coverage Report for Build 672

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.956%

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Totals
Change from base Build 670:	0.0%
Covered Lines:	3223
Relevant Lines:	3257

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 672

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.956%

---

Totals
Change from base Build 670:	0.0%
Covered Lines:	3223
Relevant Lines:	3257

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 672

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.956%

---

Totals
Change from base Build 670:	0.0%
Covered Lines:	3223
Relevant Lines:	3257

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 672

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.956%

---

Totals
Change from base Build 670:	0.0%
Covered Lines:	3223
Relevant Lines:	3257

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 672

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.956%

---

Totals
Change from base Build 670:	0.0%
Covered Lines:	3223
Relevant Lines:	3257

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 672

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.956%

---

Totals
Change from base Build 670:	0.0%
Covered Lines:	3223
Relevant Lines:	3257

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 672

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.956%

---

Totals
Change from base Build 670:	0.0%
Covered Lines:	3223
Relevant Lines:	3257

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 672

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.956%

---

Totals
Change from base Build 670:	0.0%
Covered Lines:	3223
Relevant Lines:	3257

---

💛 - Coveralls

[Andrew-Chen-Wang]

@Natureshadow I'm planning on removing those databases in the next release. You can add support yourself by adding in your settings: https://django-cachalot.readthedocs.io/en/latest/quickstart.html#cachalot-databases

[Natureshadow]

So, what does this mean for supporting the cache backends?

[Andrew-Chen-Wang]

Most important thing:

django-cachalot/cachalot/apps.py

Lines 25 to 36 in d0b5213

	@register(Tags.caches, Tags.compatibility)
	def check_cache_compatibility(app_configs, **kwargs):
	cache = settings.CACHES[cachalot_settings.CACHALOT_CACHE]
	cache_backend = cache['BACKEND']
	if cache_backend not in SUPPORTED_CACHE_BACKENDS:
	return [Warning(
	'Cache backend %r is not supported by django-cachalot.'
	% cache_backend,
	hint='Switch to a supported cache backend '
	'like Redis or Memcached.',
	id='cachalot.W001')]
	return []

So even if your cache is configured as:

CACHES = {

"default": {"BACKEND": "whatever"}
}

Django only raises a warning, and you can mute the warning. Unlike the databases setting, this one will not raise an error, only a warning which can be muted in your settings.

We use Django's regular django.core.cache.cache API. So if your app also uses something like:

from django.core.cache import cache

cache.get("key")

and the regular basic ones found in BaseCache, then cachalot should support it. I believe, IIRC, we only use get or set.

[Natureshadow]

Great, thanks!