Loki: Port change to 8080 broke docker-compose example

[Mario-Hofstaetter]

Describe the bug
Default Port was changed from http_listen_port: 3100 to http_listen_port: 8080 in #1823
This breaks the docker-compose.yaml example, which is still using 3100.
You cannot connect to loki from grafana if you use compose and wonder why.

Also several docs still state 3100, as does the placeholder in grafana add datasource ui.

To Reproduce
Use the linked docker-compose.yaml with current docker image of grafana/loki
You won't be able to connect if you try 3100.

Is the future default port of loki 8080 ?

[cliv]

Specifically, it looks like https://github.com/grafana/loki/pull/1823/commits/cde1ad84b7118846f7b61f24768753d3a899ed26#diff-17af4cf9a6bbf96dc43ad4544bfad96bL4 was the breaking change.

If one was running with the default configuration file (/etc/loki/local-config.yaml) specified in /production/docker-config.yml, loki was never running on port 80 in the first place - so why change it? Why use 8080 as the default in the first place instead of 3100?

[wardbekker]

@cyriltovena The port change in cmd/loki/loki-local-config.yaml from 3100 => 8080 seems not needed? Or at least not consisent with other configuration. Bunch of config still assumes loki to be available on port 3100, like promtail default config here: https://github.com/grafana/loki/blob/master/cmd/promtail/promtail-local-config.yaml#L9

[cyriltovena]

We made a change in the docker image to run loki as non-root user. This has caused us trouble in our environment because 80 can't be bound without root.

This is why we made changes to the port binding in the docker image.

[cyriltovena]

I'll make it 3100 everywhere.