Logging using Grafana and Loki

In this article, we will set logging services like Grafana for our docker containers.
Only in simple three steps, we will achieve our Grafana dashboard.

1. Step 1: Set up Loki on your machine.

   For setting up Loki, I prefer the Loki docker image because it is easy to set up and easy to use.

   1. Create a folder for the Loki config file, the most important file in Loki management, to run Loki and can be useful for debugging configuration issues.

       mkdir loki
       cd loki
      

   2. Now install the config file using:

       wget https://raw.githubusercontent.com/grafana/loki/v3.0.0/cmd/loki/loki-local-config.yaml -O loki-config.yaml
      

   3. Now run the following command to run the docker container, and verify that your container is running:

       docker run --name loki -d -v $(pwd):/mnt/config -p 3100:3100 grafana/loki:3.0.0 -config.file=/mnt/config/loki-config.yaml
       docker ps -a
      

      
       CONTAINER ID   IMAGE                    COMMAND                  CREATED              STATUS              PORTS                                       NAMES
       4abe5216a6fd   grafana/loki:3.0.0       "/usr/bin/loki -conf…"   About a minute ago   Up About a minute   0.0.0.0:3100->3100/tcp, :::3100->3100/tcp   loki
      

2. Step 2: Installing Grafana in your machine and initializing it

   1. For setting the Grafana container we need to pass one command only:

       docker run -d -p 3000:3000 --name=grafana grafana/grafana-enterprise
      

      Verify whether your container is running or not:

       docker ps -a
      

       ONTAINER ID    IMAGE                        COMMAND     CREATED              STATUS              PORTS                    NAMES
       497dd81c9d25   grafana/grafana-enterprise   "/run.sh"   About a minute ago   Up About a minute   0.0.0.0:3000->3000/tcp   grafana
      

   2. Now move to your browser and visit http://localhost:3000 or if using a VM use http://<machine_public_ip>:3000 (make sure you enable port 3000 and 3100 in inbound rules in case of VM), and log in using default username and password (admin, admin).

      

   3. Now, on the dashboard go to connections and click add a new connection from the left pane.

      

      Choose Loki from the given data sources. Now, in the connection input add Loki URL(http://localhost:3100, or http://<machine_public_ip>:3100), and hit the save & test button.

      

      After this step, our Loki is connected successfully with our Grafana.

3. Step 3: Attach your docker logs with the Loki instance

   To streamline the process, each time we execute our docker image, ensure its logger driver is configured to Loki with the provided command:

    docker run --log-driver=loki \
        --log-opt loki-url="http://<machine_ip:3100>/loki/api/v1/push" \
        --log-opt loki-retries=5 \
        --log-opt loki-batch-size=400 \
        <image_name>
   

   Now move to your Grafana dashboard and select the explore tab from the left pane. In the label filter section choose "container" and your container name as its value.

   

   And hit the run query button.
   If everything works properly your container logs will be visible.

   

   Now you can personalize the Grafana dashboard based on your preference for the graphs you want to visualize.

Reference: https://grafana.com/docs