PSInflux

This Powershell 3+ module uses Influx DB HTTP API to query and send data.

To install, clone this project then run: cinst fzf; ./install.ps1

How to use

Set the following environment variables or put them in $PROFILE:

$ENV:INFLUX_SERVER = "http://influxdb.server.com:8086"
$ENV:INFLUX_DB     = "mydb"

Load with import-module psinflux. You can use normal PowerShell commands to get help:

List of functions: gcm -Module psinflux
Help for function: man iq

Query

Use iq (alias for Send-Query) to query the database:

iq select value,tag from measure limit 20

For convenience, you don't generally have to put a query inside a PowerShell string.

iq (influx query) function parses returned data into PowerShell objects which can be slow for large number of points. Use iqr (raw query) to get large collections.

Templates

Use itemplate (alias for Invoke-Template) to send predefined queries. Predefined queries can be added by the user and can contain PowerShell placeholders for getting the user input, for example metric or database name. Integrated templates use fzf (install via chocolatey: cinst fzf) fuzzy finder as input selector.

Default template is always used and has several predefined queries and selectors/input methods. You can add your own template by using a $FilePath parameter or setting $Env:INFLUX_TEMPLATE environment variable. User template is then merged with the default one.

Query templates are text files that contain two sections: powershell code and query sentences. Two sections are separated by '---' line. Comments are marked with #.

User can define small Powershell helper scriptblocks and Powershell variables that serve to replace query placeholders, marked with $PLACEHOLDER keywords. There are 2 specially named placeholders, those starting with SELECT_ or INPUT_ that are replaced with scriptblock invocations. Other $ prefixed words are simple PowerShell variables. Default template defines few generally useful selectors can be reused in user template.

For example, user template can look like this:

$SELECT_CPU_FIELDS = { ( iq show field keys from cpu  | % fieldkey | fzf "Select 1 or more CPU (with TAB key) fields") -join ',' }

---

select $SELECT_CPU_FIELDS from cpu limit 50    # Select field from the CPU metric

Writing data

To write data points to the database use Send-Data function:

$cpu_load = Get-Counter '\Processor(_Total)\% Processor Time' | % CounterSamples | % CookedValue
Send-Data "cpu,host=$Env:COMPUTERNAME,user=$Env:USERNAME value=$cpu_load"

You can use [DateTime]::UtcNow.ToString('o') to send date time instead of nanoseconds until Unix epoch. If you do that, pass parameter $UseRoundTripTime to make function automatically convert time points to correct format.

You can also send an array of strings:

$time = [DateTime]::UtcNow.ToString('o')
Send-Data "test1 value=1 $time", "test2 value=2 $time" -RoundTripTime

Here is another example:

PS> 1..10 | % { $x = 10*$_ + (Get-Random 10); Send-Data "test1 value=$x"; sleep 1 }

StatusCode StatusDescription Headers
---------- ----------------- -------
       204 No Content        {[Request-Id, 03fed428-2fee-11e7-8c50-000000000000], [X-Influxdb-Version, 1.2.2], [Content-Type, application/json], [Date, Wed, 03 May 2017 10:48:17 GMT]}
       204 No Content        {[Request-Id, 04997ca0-2fee-11e7-8c51-000000000000], [X-Influxdb-Version, 1.2.2], [Content-Type, application/json], [Date, Wed, 03 May 2017 10:48:18 GMT]}
       ...

 
PS> iq select value from test1 order by time desc

time                           value
----                           -----
2017-05-03T10:48:26.893855822Z   109
2017-05-03T10:48:25.841784978Z    94
2017-05-03T10:48:24.789887277Z    85
2017-05-03T10:48:23.729787415Z    78
2017-05-03T10:48:22.673721527Z    66
2017-05-03T10:48:21.617741836Z    56
2017-05-03T10:48:20.561755378Z    40
2017-05-03T10:48:19.497824954Z    38
2017-05-03T10:48:18.437837385Z    23
2017-05-03T10:48:17.384615849Z    17

Send to StatsD

You can use Send-Statsd to write to Statsd server. The following example uses Telegraf as StatsD server so sending tags is supported: