This was primarily intended to consume InfluxDB-style expvars,
particularly InfluxDB's `/debug/vars` endpoint.
That endpoint follows a structure like
```json
{
"httpd::8086": {
"name": "httpd",
"tags": {
"bind": ":8086"
},
"values": {
"pointsWrittenOK": 33756,
"queryReq": 19,
"queryRespBytes": 26973,
"req": 428,
"writeReq": 205,
"writeReqBytes": 3939161
}
}
}
```
There are an arbitrary number of top-level keys in the JSON response at
the configured URLs, and this plugin will iterate through all of their
values looking for objects with keys "name", "tags", and "values"
indicating a metric to be consumed by telegraf.
Running this on current master of InfluxDB, I am able to record nearly
the same information that is normally stored in the `_internal`
database; the only measurement missing from `_internal` is `runtime`,
which is present under the "memstats" key but does not follow the format
and so is not consumed in this plugin.
```
$ influx -database=telegraf -execute 'SHOW FIELD KEYS FROM /influxdb/'
name: influxdb_influxdb_engine
----------------------------
fieldKey
blksWrite
blksWriteBytes
blksWriteBytesC
pointsWrite
pointsWriteDedupe
name: influxdb_influxdb_httpd
---------------------------
fieldKey
pingReq
pointsWrittenOK
queryReq
queryRespBytes
req
writeReq
writeReqBytes
name: influxdb_influxdb_shard
---------------------------
fieldKey
fieldsCreate
seriesCreate
writePointsOk
writeReq
name: influxdb_influxdb_subscriber
--------------------------------
fieldKey
pointsWritten
name: influxdb_influxdb_wal
-------------------------
fieldKey
autoFlush
flushDuration
idleFlush
memSize
metaFlush
pointsFlush
pointsWrite
pointsWriteReq
seriesFlush
name: influxdb_influxdb_write
---------------------------
fieldKey
pointReq
pointReqLocal
req
subWriteOk
writeOk
```
and rearrange the order to match the index order from the CSV endpoint
add test coverage. add back wretr. remove check_status from recently added column
closes#445
And unit test it using a sample response string. This will make it
easier to see what other metrics are available to the plugin for adding
future metrics.
Cameron Sparr
Mark Rushakoff
chrispeterson
jipperinbham
Allen Petersen
Nathaniel Cook
Carlos J. Torres
Mischa Gresser