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Alex
Alex

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loki && curl && logcli

With https://community.ops.io/la3mmchen/grafana-loki-28b9 I've shared some words on Loki as an introduction.

Lets follow up with some practical stuff: How can we run Loki an our local notebook with docker-compose?

Loki

As Grafana provides a good enough container images we just use the one from docker hub to get a local instance running.

---
version: "3.9"

services:
  loki:
    image: "grafana/loki:2.5.0"
    ports:
      - "3100:3100"
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As Loki follows the unix philosophy "Do One Thing and Do It Well" it's just a backend to send logs to and to query logs from.
Plain speaking: there is no graphical user interface in the Loki server.

We interact with the Loki instance with curl using the http api:

$  curl http://localhost:3100/ready  
ready
$ curl http://localhost:3100/loki/api/v1/labels
{"status":"success","data":["__name__"]}
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As the second request shows there are not many labels in the system yet.

Lets change this.

interact with curl

Loki offers a http api to send metrics. The data format is described at http push api, we use the following curl to create a new event stream:

$ curl -S -H "Content-Type: application/json" -XPOST -s http://localhost:3100/loki/api/v1/push --data-raw '{"streams": [{ "stream": { "app": "app1" }, "values": [ [ "1653855518000000000", "random log line" ] ] }]}'
$ curl http://localhost:3100/loki/api/v1/labels
{"status":"success","data":["__name__","app"]}
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As you can see in the second curl there is now a new label named "app". We can explore possible values for this label with the following curl.

$ curl http://localhost:3100/loki/api/v1/label/app/values
{"status":"success","data":["app1"]}
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And finaly see the stream with this label:

$ curl -G -Ss  http://localhost:3100/loki/api/v1/query_range --data-urlencode 'query={app="app1"}' | jq .
{
  "status": "success",
(...)
        "values": [
          [
            "1653855518000000000",
            "random log line"
          ]
        ]
      }
(...)
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(output shorted)

logcli

A more covenient way to interact with Loki from the command line is using logcli

$ LOKI_ADDR=http://localhost:3100 logcli labels
http://localhost:3100/loki/api/v1/labels?end=1653856566774536000&start=1653852966774536000
__name__
app
$ LOKI_ADDR=http://localhost:3100 logcli query '{app=~".+"}'
http://localhost:3100/loki/api/v1/query_range?direction=BACKWARD&end=1653856568404563000&limit=30&query=%7Bapp%3D~%22.%2B%22%7D&start=1653852968404563000
Common labels: {app="app1"}
2022-05-29T22:18:38+02:00 {} random log line
http://localhost:3100/loki/api/v1/query_range?direction=BACKWARD&end=1653855518000000001&limit=30&query=%7Bapp%3D~%22.%2B%22%7D&start=1653852968404563000
Common labels: {app="app1"}
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in case you do not want to install logcli locally just add another container to our docker-compose setup from the beginning of this article:

(..)
  logcli:
    image: "grafana/logcli:2.5.0-amd64"
    environment:
      - "LOKI_ADDR=http://loki:3100"
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with this container you can just do:

$ docker-compose run logcli labels
Creating loki_logcli_run ... done
(..)
__name__
app
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following up

in the next post we will add a grafana instance to our docker-compose that will enable us to click something ;-)

references

links

code reference

---
version: "3.9"

services:
  loki:
    image: "grafana/loki:2.5.0"
    ports:
      - "3100:3100"
  logcli:
    image: "grafana/logcli:2.5.0-amd64"
    environment:
      - "LOKI_ADDR=http://loki:3100"
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Top comments (48)

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emmasmith profile image
Emma Smith

Thanks for sharing! If you’re exploring food options or planning your next meal, checking restaurant menus online can really save time and make decisions easier. Well-organized menu sites are especially helpful when you’re in a rush or ordering for a group, letting you quickly compare items, prices, and choices. For a smooth browsing experience, check out easy menu browsing guide to find meals that match your taste and budget.

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david_4cdae633ac8f7656de1 profile image
David

Once your work is complete or after you have eaten, choose meals prepared with fresh and nutritious ingredients to help maintain your energy levels and overall health .

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chickfila_menu_3e6bbe3548 profile image
chickfila menu

Consistent use of an ACFT calculator allows you to log your scores over time. This data can then be visualized on an ACFT score chart or ACFT scorecard, offering a clear picture of your progress. theacftcalculator.us/

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wendys_menu_9d16407a981c profile image
Wendy's Menu

Nice write-up! If you're looking for a quick, delicious option while working, check out our Wendys Menu—complete, easy to browse, and perfect when you need something tasty on the go!

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jack_intheboxmenu_9ed5 profile image
Jack in the box menu

Nice write-up! By the way, if you're craving a quick, tasty bite while tinkering with this setup, take a peek at our Jack in the Box Tacos Menu—easy to browse and perfect fuel for your dev workflow!

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panada_expressmenu_3450d profile image
Panada Express Menu

Great tips here! Also, for anyone looking for the latest Panda Express offerings, check out the full Panda Menu—it’s super easy to browse and see all the options available!

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burger_kingmenu_d4ae2673 profile image
Burger King Menu

Thanks for sharing! I found this really helpful. By the way, if anyone’s looking for an updated list, check out the full Burger King Menue with prices—it’s super easy to navigate and really detailed!

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wendys_menu_1f6cd4c61b68 profile image
Wendy's Menu

Wendy’s menu croissants are such a delicious breakfast pick — soft, buttery, and filled with savory goodness. Whether it’s sausage, bacon, or egg, each croissant sandwich feels like a cozy morning treat. Perfect for a quick yet satisfying start to the day!

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us_menu_0eb41e2a7f180fe4e profile image
Us Menu

The Sonic menu is amazing! It offers a great mix of classic fast-food favorites, refreshing drinks, and sweet treats — perfect for anyone who loves variety and great taste.

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shoaib_akhtar_7b7fbf63239 profile image
Shoaib Akhtar

Loki, Curl, and Logcli are powerful tools for managing and querying logs efficiently. ⚙️🔥 Together, they make log analysis faster and more flexible — perfect for developers and system admins who need reliable observability and real-time monitoring. Parivahan sewa

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