Scrape timestamp metrics as value

[minefuto]

Is your feature request related to a problem? Please describe.
I want to scrape timestamp metrics as value(not label) from ACI such as modTs.

{
   "totalCount":"1",
   "imdata":[
      {
         "infraWiNode":{
            "attributes":{
               -snip-
               "modTs":"2020-04-18T05:24:07.722+00:00",

Describe the solution you'd like
I think aci-exporter need to translate from "2020-04-18T05:24:07.722+00:00" to unixtime.

Do you have any plans to add the above function?
Or is it already implemented?

[thenodon]

Hi @minefuto,
Can you provide the aci config, so I can se the query you are running.
When it comes to recalculate the value there is currently options as value_transform and value_calculation.
A value transform some string value to a float.

value_transform:
          'unknown': 0
          'down': 1
          'up': 2
          'link-up': 3

A value_calculation can make some simple calculations of the value. This example divide the value (value-string is a placeholder for the value) with 100.
value_calculation: "value / 100"

aci-exporter use https://github.com/Knetic/govaluate to execute the expression like "value / 100". In govaluate it is possible to create addtional "functions" that can be called, see https://github.com/Knetic/govaluate#functions. So it might be possible to create some additional functions for your use case.

[minefuto]

Thanks @thenodon,
I think Knetic/govaluate only supported to transform from string to Time type.
Not supported from string to unixtime(float).

I want to detect link flap of ACI.
config.yaml

class_queries:
  interface_info:
    class_name: interface_info
    metrics:
      - name: lastLinkStChg
        value_name: ethpmPhysIf.attributes.lastLinkStChg
        type: gauge
    labels:
      - property_name: ethpmPhysIf.attributes.dn
        regex: "^topology/pod-(?P<podid>[1-9][0-9]*)/node-(?P<nodeid>[1-9][0-9]*)/sys/phys-\\[(?P<interface>[^\\]]+)\\]/"

prometheus-rules.yml

groups:
- name: alert
  rules:
  - alert: "interface flap"
    expr: changes(aci_lastLinkStChg[5m]) > 0
    for: 1m

But lastLinkStChg cannot scraped because it is string such as 2020-04-18T05:24:07.722+00:00.
So aci-exporter should get lastLinkStChg as a unixtime(float).

example:
minefuto@0691f56

[thenodon]

I understand your use case and it make sense to understand flapping. I still think it could be done with https://github.com/Knetic/govaluate#functions.
We could implement a govaluate function like date_to_unixtime(.....) and in your aci config have

class_queries:
  interface_info:
    class_name: interface_info
    metrics:
      - name: lastLinkStChg
        value_name: ethpmPhysIf.attributes.lastLinkStChg
        type: gauge
        value_calculation: "date_to_unixtime(value, "rfc_3339")
    labels:
      - property_name: ethpmPhysIf.attributes.dn
        regex: "^topology/pod-(?P<podid>[1-9][0-9]*)/node-(?P<nodeid>[1-9][0-9]*)/sys/phys-\\[(?P<interface>[^\\]]+)\\]/"

The functions needs to be part of the parsing so a refactor of func valueReCalculation(...) needs to be done. I would be preferable that the govaluate function could be "loaded" at start up (reflection) to support custom function in additions to standard functions provided by aci-exporter.
This is just my thought and I have not done any testing. Would be great to know if there are a general request for this functionality.

[minefuto]

Thanks, I understand your idea.
It looks like a good.

[thenodon]

@minefuto please checkout branch issue_12 and test the fix. aci-export will now automatically convert date in rfc3339 format to a float. Hopefully all dates are in that format.
Use the config like:

class_queries:
  interface_lastlink_st_chg_to_date:
    class_name: ethpmPhysIf
    metrics:
      - name: lastLinkStChg
        value_name: ethpmPhysIf.attributes.lastLinkStChg
        type: counter
    labels:
      # The field in the json used to parse the labels from
      - property_name: ethpmPhysIf.attributes.dn
        # The regex where the string enclosed in the P<xyz> is the label name
        regex: "^topology/pod-(?P<podid>[1-9][0-9]*)/node-(?P<nodeid>[1-9][0-9]*)/sys/phys-\\[(?P<interface>[^\\]]+)\\]/"

[minefuto]

I confirmed it solves this issue.

By the way, I found a problem in branch issue_12 that fails to go build.
I think It should be updated go.sum.

~/aci-exporter
❯ go version
go version go1.17.2 darwin/amd64

~/aci-exporter
❯ git switch issue_12
Branch 'issue_12' set up to track remote branch 'issue_12' from 'origin'.
Switched to a new branch 'issue_12'

~/aci-exporter
❯ go build
go: github.com/tidwall/gjson@v1.9.3: missing go.sum entry; to add it:
	go mod download github.com/tidwall/gjson
go: github.com/tidwall/gjson@v1.9.3: missing go.sum entry; to add it:
	go mod download github.com/tidwall/gjson

[thenodon]

Thanks for the feedback and glad that it worked. Will fix the go.sum.
If you like to share your experience with aci-exporter, you can email me on ahaal@redbridge.se