"No logs found" in grafana - loki

Question

I installed Loki, grafana and promtail and all three runing. on http://localhost:9080/targets Ready is True, but the logs are not displayed in Grafana and show in the explore section "No logs found"
promtail-local-config-yaml:
server:
http_listen_port: 9080
grpc_listen_port: 0
positions:
filename: /tmp/positions.yaml
clients:
- url: http://localhost:3100/loki/api/v1/push
scrape_configs:
- job_name: system
static_configs:
- targets:
- localhost
labels:
job: varlogs
host: ward_workstation
agent: promtail
__path__: D:/LOGs/*log
loki-local-config.yaml:
auth_enabled: false
server:
http_listen_port: 3100
grpc_listen_port: 9096
common:
path_prefix: /tmp/loki
storage:
filesystem:
chunks_directory: /tmp/loki/chunks
rules_directory: /tmp/loki/rules
replication_factor: 1
ring:
instance_addr: 127.0.0.1
kvstore:
store: inmemory
schema_config:
configs:
- from: 2020-10-24
store: boltdb-shipper
object_store: filesystem
schema: v11
index:
prefix: index_
period: 24h
ruler:
alertmanager_url: http://localhost:9093
How can i solve this problem?

Answer 1

Perhaps you are using Loki in Windows ?
In your promtail varlogs job ,the Path "D:/LOGs/*log" is obviously wrong, you cannot access the windows file from your docker directly.
You shoud mount your windows file to your docker like this:
promtail:
image: grafana/promtail:2.5.0
volumes:
- D:/LOGs:/var/log
command: -config.file=/etc/promtail/config.yml
networks:
- loki
Then everything will be ok.
Note that, in your promtail docker the config is like this:
you can adjust both to make a match...

Answer 2

Here's a general advice how to debug Loki according to the question's title:
(1) Check promtail logs
If you discover such as error sending batch you need to fix your Promtail configuration.
level=warn ts=2022-10-12T16:26:20.667560426Z caller=client.go:369 component=client host=monitor:3100 msg="error sending batch, will retry" status=-1 error="Post \"http://loki:3100/loki/api/v1/push\": dial tcp: lookup *Loki* on 10.96.0.10:53: no such host"
(2) Open the Promtail config page and check, if Promtail has read your given configuration: http://localhost:3101/config
(3) Open the Promtail targets page http://localhost:3101/targets and check
if your service is listed as Ready
if the log file contains the wanted contents and is readable by Promtail. If you're using docker or kubernetes I would log into the Promtail Container and would try to read the logfile manually.
To the specific problem of the questioner:
The questioner said, that the services are shown as READY in the targets page. So I recommend to check (1) Promtail configuration and (3b) access to log files (as Frank).