Fix json_v2 parser to handle nested objects in arrays properly

[sspaink]

• Wrote appropriate unit tests.

@sjwang90 found an issue when parsing the following JSON that would result in empty metrics:

{
    "features": [
        {
            "properties": {
                "mag": 5.17
            }
        }
    ]
}

Config used:

[[inputs.file]]
    files = ["./testdata/test/input.json"]
    data_format = "json_v2"
    [[inputs.file.json_v2]]
            [[inputs.file.json_v2.object]]
                path = "features"

This pull request resolves this problem by updating the part where the metrics were being discarded.

[telegraf-tiger]

Looks like new artifacts were built from this PR. Get them here!

Artifact URLs

• windows_amd64.zip

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• darwin_amd64.tar.gz

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• aarch64.rpm

• linux_arm64.tar.gz

• arm64.deb

• linux_mips.tar.gz

• mips.deb

• linux_mipsel.tar.gz

• mipsel.deb

• s390x.rpm

• linux_s390x.tar.gz

• s390x.deb

• ppc64le.rpm

• linux_ppc64le.tar.gz

• ppc64el.deb

• armv6hl.rpm

• freebsd_armv7.tar.gz

• linux_armhf.tar.gz

• armhf.deb

• i386.rpm

• freebsd_i386.tar.gz

• linux_i386.tar.gz

• i386.deb

• x86_64.rpm

• freebsd_amd64.tar.gz

• linux_amd64.tar.gz

• amd64.deb

• armel.rpm

• linux_armel.tar.gz

• armel.deb

[sjwang90]

Nice!!! This worked for me

Config

[[inputs.http]]
  urls = [
    "https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/significant_week.geojson"
  ]
  name_override = "earthquake"
  tagexclude = ["url", "host"]
  data_format = "json_v2"
  [[inputs.http.json_v2]]
        [[inputs.http.json_v2.object]]
            path = "features"
            timestamp_key = "properties_time"
            timestamp_format = "unix_ms"
            tags = ["properties_place"]
            # excluded_keys = ["properties_detail", "properties_url", "properties_status", "properties_ids", "properties_sources", "properties_types"]
            included_keys = ["properties_mag"]

Output:

> earthquake,properties_place=12\ km\ NNW\ of\ Kukuihaele\,\ Hawaii properties_mag=5.17 1625700002000000000
> earthquake,properties_place=4km\ NNW\ of\ Fontana\,\ CA properties_mag=3.41 1625700002000000000