Default location 2

[KanishkaVerma054]

What this PR does / why we need it:

Which issue(s) this PR fixes: cmd/loki/loki-local-config.yaml for not loosing any data
Fixes #7781

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide
• Documentation added
• Tests updated
• CHANGELOG.md updated
• Changes that require user attention or interaction to upgrade are documented in docs/sources/upgrading/_index.md

[grafanabot]

./tools/diff_coverage.sh ../loki-target-branch/test_results.txt test_results.txt ingester,distributor,querier,querier/queryrange,iter,storage,chunkenc,logql,loki

Change in test coverage per package. Green indicates 0 or positive change, red indicates that test coverage for a package fell.

+           ingester	0%
+        distributor	0%
+            querier	0%
+ querier/queryrange	0%
+               iter	0%
+            storage	0%
+           chunkenc	0%
+              logql	0%
+               loki	0%

[chaudum]

Changing the locations to /var/lib/loki would require to run Loki as a user with privileges writing to /var/lib.

$ ls -lash /var/lib/
total 220K
4.0K drwxr-xr-x 54 root          root          4.0K Nov 25 18:53 .
4.0K drwxr-xr-x 12 root          root          4.0K Sep 15 14:50 ..

Otherwise Loki will not start up due to missing privileges:

$ ./cmd/loki/loki -target=all -config.file=cmd/loki/loki-local-config.yaml
mkdir /var/lib/loki: permission denied
error initialising module: ruler-storage
github.com/grafana/dskit/modules.(*Manager).initModule
	/home/christian/sandbox/grafana/loki/vendor/github.com/grafana/dskit/modules/modules.go:122
github.com/grafana/dskit/modules.(*Manager).InitModuleServices
	/home/christian/sandbox/grafana/loki/vendor/github.com/grafana/dskit/modules/modules.go:92
github.com/grafana/loki/pkg/loki.(*Loki).Run
	/home/christian/sandbox/grafana/loki/pkg/loki/loki.go:419
main.main
	/home/christian/sandbox/grafana/loki/cmd/loki/main.go:105
runtime.main
	/usr/local/go-1.19/src/runtime/proc.go:250
runtime.goexit
	/usr/local/go-1.19/src/runtime/asm_amd64.s:1594

In my case, I would need to create and change ownership of /var/lib/loki, like so:

$ sudo mkdir -pv /var/lib/loki && sudo chown -R christian:christian /var/lib/loki
[sudo] password for christian: 
mkdir: created directory '/var/lib/loki'

Since this config file is referenced in a few places in the docs (and in the README), we need to make sure we don't break these examples, otherwise it's not a very good user experience.

[MasslessParticle]

The loki-local configuration is intended to get up and running as soon as a possible and not for direct production use. I don't think we should change this.

Thank you for your contribution!