From e963e78e1f22c9fffd3ac2ddbd403b3c44253e20 Mon Sep 17 00:00:00 2001
From: Lukas Malkmus <mail@lukasmalkmus.com>
Date: Tue, 20 Dec 2022 13:12:00 +0100
Subject: [PATCH] fix: better label names

---
 README.md                         | 20 ++++++++++++++++++--
 cmd/tankerkoenig_exporter/main.go | 22 +++++++++++++++++++++-
 internal/exporter/exporter.go     |  6 +++---
 3 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 7b28c2d..edc5716 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,22 @@ Docker images are available on the [GitHub Package Registry].
 docker run -p9386:9386/tcp --env-file=.env ghcr.io/lukasmalkmus/tankerkoenig-exporter:0.10.0 --tankerkoenig.stations="51d4b55e-a095-1aa0-e100-80009459e03a"
 ```
 
+## Querying
+
+The exporter exposes the following Tankerkoenig API related metrics (there are
+a handful of exporter related metrics as well, like `up`, etc.):
+
+- `tk_station_price_euro{id, product}`: The fuel price in euro per liter.
+- `tk_station_open{id}`: Whether the station is open (`1`) or not (`0`).
+- `tk_station_details{id, name, address, city, geohash, brand}`: Details of the station.
+
+If you want to add station details when querying the price metric, you can join
+the two metrics like this:
+
+```promql
+tk_station_price_euro * on (id) group_left(brand, address) tk_station_details
+```
+
 ## Contributing
 
 Feel free to submit PRs or to fill Issues. Every kind of help is appreciated.
@@ -83,8 +99,8 @@ See [LICENSE](LICENSE) for more information.
 
 <!-- Links -->
 
-[tankerkoenig api]: https://creativecommons.tankerkoenig.de/#usage
-[tankerkoenig site]: https://creativecommons.tankerkoenig.de/#usage
+[tankerkoenig api]: https://creativecommons.tankerkoenig.de/home
+[tankerkoenig site]: https://creativecommons.tankerkoenig.de/api-key
 [tankstellen finder]: https://creativecommons.tankerkoenig.de/TankstellenFinder/index.html
 [github package registry]: https://github.com/lukasmalkmus/tankerkoenig_exporter/pkgs/container/tankerkoenig_exporter
 
diff --git a/cmd/tankerkoenig_exporter/main.go b/cmd/tankerkoenig_exporter/main.go
index be57257..718276b 100644
--- a/cmd/tankerkoenig_exporter/main.go
+++ b/cmd/tankerkoenig_exporter/main.go
@@ -38,7 +38,27 @@ Example:
     $ tankerkoenig_exporter --tankerkoenig.stations 51d4b55e-a095-1aa0-e100-80009459e03a
     $ tankerkoenig_exporter --tankerkoenig.location u0yjjd6jk0zj7 --tankerkoenig.radius=3 --tankerkoenig.product=e5
 
-The --tankerkoenig.stations flag is mutually exclusive with the --tankerkoenig.location flag.
+The --tankerkoenig.stations flag is mutually exclusive with the
+--tankerkoenig.location, --tankerkoenig.radius and --tankerkoenig.product flags.
+
+KEY can be obtained from https://creativecommons.tankerkoenig.de/api-key.
+
+UUID is the unique identifier of a station. It can be obtained from the
+Tankerkoenig API or by using the Tankstellen Finder:
+https://creativecommons.tankerkoenig.de/TankstellenFinder/index.html.
+
+GEOHASH is the geohash of a location. It can easily be obtained from the
+internet.
+
+KM is the search radius in kilometers. Must be a positive integer.
+
+PRODUCT is the fuel type. Must be one of e5, e10, diesel or all to include all
+products.
+
+ADDRESS is the listen address for the web server. It must be in the form of
+[HOST]:PORT.
+
+PATH is the path under which to expose metrics. It must start with a slash.
 `
 
 type stringSliceValue []string
diff --git a/internal/exporter/exporter.go b/internal/exporter/exporter.go
index 5b112d1..49ed2ba 100644
--- a/internal/exporter/exporter.go
+++ b/internal/exporter/exporter.go
@@ -246,19 +246,19 @@ func newExporter(logger *log.Logger, apiClient *client.Client) *Exporter {
 		priceDesc: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, "station", "price_euro"),
 			"Gas prices in EURO (€).",
-			[]string{"station_id", "product"},
+			[]string{"id", "product"},
 			nil,
 		),
 		openDesc: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, "station", "open"),
 			"Status of the station. 1 for OPEN, 0 for CLOSED.",
-			[]string{"station_id"},
+			[]string{"id"},
 			nil,
 		),
 		detailsDesc: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, "station", "details"),
 			"Associated details of a station. Always 1.",
-			[]string{"station_id", "station_name", "address", "city", "geohash", "station_brand"},
+			[]string{"id", "name", "address", "city", "geohash", "brand"},
 			nil,
 		),
 	}