Add useCurrentTime flag to HTTP metrics output timestamping

[Copilot]

nOutput_HTTP_Metrics always emitted OpenMetrics timestamps based on recorded attribute/warning retrieval times. This change adds an opt-in useCurrentTime flag to emit scrape-time timestamps (Date.now()) instead.

• Configuration

  • Added new boolean option in config/objects/nOutput_HTTP_Metrics.js:
    • useCurrentTime (default: false)

• Timestamp selection for value/warning parsing

  • Updated _parse (current/last values) and _parsew (warnings) to select timestamp via:
    • recorded time when useCurrentTime=false (existing behavior)
    • Date.now() when useCurrentTime=true

• Self metrics timestamping

  • Updated both OpenMetrics self-output paths in /metrics handler to pass an explicit timestamp only when useCurrentTime=true:
    • __ow_metrics_fromObj2OpenMetrics(ow.metrics.getAll(), parent.nameSelf, parent.useCurrentTime ? Date.now() : undefined)

Example:

useCurrentTime: true

var d = parent.useCurrentTime ? Date.now() : (new Date(r.date)).getTime();

Original prompt

Summary

Modify config/objects/nOutput_HTTP_Metrics.js to support a new boolean option flag useCurrentTime (defaults to false). When set to true, the current time (Date.now()) should be used as the timestamp passed to ow.metrics.fromObj2OpenMetrics / __ow_metrics_fromObj2OpenMetrics, instead of the recorded retrieval time stored in the attribute value.

Changes Required

1. Constructor — accept and store the new flag

In the nOutput_HTTP_Metrics constructor (where other flags like includeSelf, includeCVals, etc. are read from aMap), add:

this.useCurrentTime = _$(aMap.useCurrentTime, "useCurrentTime").isBoolean().default(false);

2. _parse function — use current time when flag is set

Current code (around line 294–303):

var _parse = (e, n) => {
    return ow.obj.fromObj2Array(e).map(r => {
        var d = (new Date(r.date)).getTime();
        delete r.date;
        var m = {}; m[r.name] = r.val;
        traverse(m, (k, v, p, o) => {
            if (isNull(v)) delete o[k]
        })
        return __ow_metrics_fromObj2OpenMetrics(m, n, d);
    }).join("");
}

Change to:

var _parse = (e, n) => {
    return ow.obj.fromObj2Array(e).map(r => {
        var d = parent.useCurrentTime ? Date.now() : (new Date(r.date)).getTime();
        delete r.date;
        var m = {}; m[r.name] = r.val;
        traverse(m, (k, v, p, o) => {
            if (isNull(v)) delete o[k]
        })
        return __ow_metrics_fromObj2OpenMetrics(m, n, d);
    }).join("");
}

3. _parsew function — use current time when flag is set

Current code (around line 306–319):

var _parsew = (e, n) => {
    var _e = []
    Object.keys(e).forEach(k => {
        _e = _e.concat(e[k].map(w => {
            var d = (new Date(w.lastupdate)).getTime()
            var m = {}; m[w.title] = clone(w)
            delete m[w.title].lastupdate
            delete m[w.title].notifications
            m[w.title].num = 1
            return __ow_metrics_fromObj2OpenMetrics(m, n, d)
        }))
    })
    return _e.join("")
}

Change to:

var _parsew = (e, n) => {
    var _e = []
    Object.keys(e).forEach(k => {
        _e = _e.concat(e[k].map(w => {
            var d = parent.useCurrentTime ? Date.now() : (new Date(w.lastupdate)).getTime()
            var m = {}; m[w.title] = clone(w)
            delete m[w.title].lastupdate
            delete m[w.title].notifications
            m[w.title].num = 1
            return __ow_metrics_fromObj2OpenMetrics(m, n, d)
        }))
    })
    return _e.join("")
}

4. Self-metrics calls — pass current time when flag is set

In the /metrics route handler, the self case calls __ow_metrics_fromObj2OpenMetrics(ow.metrics.getAll(), parent.nameSelf) without any timestamp. When useCurrentTime is true, pass Date.now() as the timestamp:

Change both occurrences (in the switch(req.params.type) block and the if (parent.includeSelf) block):

// from:
__ow_metrics_fromObj2OpenMetrics(ow.metrics.getAll(), parent.nameSelf)
// to:
__ow_metrics_fromObj2OpenMetrics(ow.metrics.getAll(), parent.nameSelf, parent.useCurrentTime ? Date.now() : undefined)

Usage example (YAML config)

useCurrentTime: true   # pass current scrape time instead of recorded retrieval time

The following is the prior conversation context from the user's chat exploration (may be truncated):

User: Change objects/nOutput*Metrics.js so that given an option flag to use the current time instead of the recorded time of retrieval.

Here is the help of the function:
ow.metrics.fromObj2OpenMetrics(aObj, aPrefix, aTimestamp, aHelpMap, aConvMap) : String

• Given aObj will return a string of open metric (prometheus) metric strings. Optionally you can provide a prefix (defaults to "metric")
• and/or aTimestamp (a number in seconds or a label field, that will be used for all aObj values) and aConvMap composed of a key with a map of possible values and corresponding
• translation to numbers. Note: prefixes should not start with a digit.

Assistant: Let me start by examining the relevant files in the repository.

Assistant: Now I have a full picture of the file. Here's the plan for the changes to config/objects/nOutput_HTTP_Metrics.js:

1. Constructor — add a new useCurrentTime option flag (defaults to false).
2. _parse (line 296) — use Date.now() instead of (new Date(r.date)).getTime() when the flag is set.
3. _parsew (line 310) — use Date.now() instead of (new Date(w.lastupdate)).getTime() when the flag is set.
4. self metrics calls (lines 457 & 463) — pass Date.now() as the timestamp when the flag is set (currently no timestamp is passed at all for self-metrics).

Would you like me to open a PR with these changes, or just show you the diff first?

User: Yes

Assistant: We're waiting for your response to the confirmation dialog to proceed with creating the pull request.

This pull request was created from Copilot chat.

[abrizida]

Tested and working in my environment.