Docs: Flux support in influxdb data source in 7.1 (#25551)

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>
Co-authored-by: Diana Payton <52059945+oddlittlebird@users.noreply.github.com>

docs/sources/features/datasources/influxdb.md

 +++
 title = "Using InfluxDB in Grafana"
 description = "Guide for using InfluxDB in Grafana"
-keywords = ["grafana", "influxdb", "guide"]
+keywords = ["grafana", "influxdb", "guide", "flux"]
 type = "docs"
 aliases = ["/docs/grafana/latest/datasources/influxdb"]
 [menu.docs]
@@ -20,14 +20,18 @@ Grafana ships with a feature-rich data source plugin for InfluxDB. The plugin in
 2. In the side menu under the `Dashboards` link you should find a link named `Data Sources`.
 3. Click the `+ Add data source` button in the top header.
 4. Select *InfluxDB* from the *Type* dropdown.
+5. Select *InfluxQL* or *Flux* from the `Query Language` list.
 
-> NOTE: If you're not seeing the `Data Sources` link in your side menu it means that your current user does not have the `Admin` role for the current organization.
+> **Note:** If you're not seeing the `Data Sources` link in your side menu it means that your current user does not have the `Admin` role for the current organization.
+
+
+### InfluxQL (classic InfluxDB query)
 
 Name | Description
 ------------ | -------------
 *Name* | The data source name. This is how you refer to the data source in panels and queries.
 *Default* | Default data source means that it will be pre-selected for new panels.
-*Url* | The HTTP protocol, IP address and port of your InfluxDB API (InfluxDB API port is by default 8086)
+*URL* | The HTTP protocol, IP address and port of your InfluxDB API (InfluxDB API port is by default 8086)
 *Access* | Server (default) = URL needs to be accessible from the Grafana backend/server, Browser = URL needs to be accessible from the browser.
 *Database* | Name of your InfluxDB database
 *User* | Name of your database user
@@ -117,6 +121,61 @@ You can switch to raw query mode by clicking hamburger icon and then `Switch edi
 You can remove the group by time by clicking on the `time` part and then the `x` icon. You can
 change the option `Format As` to `Table` if you want to show raw data in the `Table` panel.
 
+## Flux support
+
+> Starting in v7.1, Grafana can execute Flux queries.
+
+The client supports Flux running on InfluxDB 1.8+.  See [1.8 compatibility](https://github.com/influxdata/influxdb-client-go/#influxdb-18-api-compatibility) for more information and connection details.
+
+
+Name | Description
+------------ | -------------
+*URL* | The HTTP protocol, IP address and port of your InfluxDB API (InfluxDB 2.0 API port is by default 9999)
+*Organization* | The [Influx organization](https://v2.docs.influxdata.com/v2.0/organizations/) that will be used for Flux queries.  This is also used to for the `v.organization` query macro
+*Token* | The authentication token used for Flux queries. With Influx 2.0, use the [influx authentication token to function](https://v2.docs.influxdata.com/v2.0/security/tokens/create-token/).  For influx 1.8, the token is `username:password` 
+*Default Bucket* | The [Influx bucket](https://v2.docs.influxdata.com/v2.0/organizations/buckets/) that will be used for the `v.defaultBucket` macro in Flux queries
+
+You can use the [Flux query and scripting language](https://www.influxdata.com/products/flux/). Grafana's Flux query editor is a text editor for raw Flux queries with Macro support.
+
+
+### Supported macros
+
+The macros support copying and pasting from [Chronograph](https://www.influxdata.com/time-series-platform/chronograf/).
+
+Macro example | Description
+------------ | -------------
+*`v.timeRangeStart`* | Will be replaced by the start of the currently active time selection. For example, *2020-06-11T13:31:00Z*
+*`v.timeRangeEnd`* | Will be replaced by the end of the currently active time selection. For example, *2020-06-11T14:31:00Z*
+*`v.windowPeriod`* | Will be replaced with an interval string compatible with Flux that corresponds to Grafana's calculated interval based on the time range of the active time selection. For example, *5s*
+*`v.defaultBucket`* | Will be replaced with the data source configuration's "Default Bucket" setting
+*`v.organization`* | Will be replaced with the data source configuration's "Organization" setting
+
+For example, the following query will be interpolated as the query that follows it, with interval and time period values changing according to active time selection\):
+
+Grafana Flux query:
+
+```flux
+from(bucket: v.defaultBucket)
+  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
+  |> filter(fn: (r) => r["_measurement"] == "cpu" or r["_measurement"] == "swap")
+  |> filter(fn: (r) => r["_field"] == "usage_system" or r["_field"] == "free")
+  |> aggregateWindow(every: v.windowPeriod, fn: mean)
+  |> yield(name: "mean")
+```
+
+Interpolated query send to Influx:
+
+```flux
+from(bucket: "grafana")
+  |> range(start: 2020-06-11T13:59:07Z, stop: 2020-06-11T14:59:07Z)
+  |> filter(fn: (r) => r["_measurement"] == "cpu" or r["_measurement"] == "swap")
+  |> filter(fn: (r) => r["_field"] == "usage_system" or r["_field"] == "free")
+  |> aggregateWindow(every: 2s, fn: mean)
+  |> yield(name: "mean")
+```
+
+You can view the interpolated version of a query with the Query Inspector.
+
 ## Querying Logs (BETA)
 
 > Only available in Grafana v6.3+.