Prometheus HTTP API support more endpoints

[yuanbohan]

What type of enhancement is this?

API improvement

What does the enhancement do?

In addition to query and query_range endpoints, as Prometheus HTTP API describes, there are some other useful endpoints which will help Prometheus users to explore the metadata or details of the datasets. And these endpoints will help greptimedb to be integrated into other systems more smoothly as a Prometheus service.

One example:

curl 'localhost:9090/api/v1/labels'
{
    "status": "success",
    "data": [
        "__name__",
        "call",
        "code",
        "config",
        "dialer_name",
        "endpoint",
        "event",
        "goversion",
        "handler",
        "instance",
        "interval",
        "job",
        "le",
        "listener_name",
        "name",
        "quantile",
        "reason",
        "role",
        "scrape_job",
        "slice",
        "version"
    ]
}

Implementation challenges

There are so many challenges to implement these endpoints as Prometheus describes, such as:

• metadata. greptimedb store no metadata at all.
• targets. greptimedb has no target concept.

[yuanbohan]

#596 needs to consider this issue carefully.

[yuanbohan]

SHOULD

• GET & POST /api/v1/query
• GET & POST /api/v1/query_range
• GET & POST /api/v1/format_query Support /api/v1/format_query from Prometheus #1540
• GET & POST /api/v1/series Support /api/v1/series from Prometheus #1539
• GET & POST /api/v1/labels Support /api/v1/labels from Prometheus #1541
• GET /api/v1/label/<label_name>/values Support /api/v1/label/<label_name>/values from Prometheus #1542

NO NEED

• GET /api/v1/targets
• GET /api/v1/rules
• GET /api/v1/alerts
• GET /api/v1/targets/metadata
• GET /api/v1/metadata
• GET /api/v1/alertmanagers
• GET & POST /api/v1/query_exemplars

status

• GET /api/v1/status/config
• GET /api/v1/status/flags
• GET /api/v1/status/runtimeinfo
• GET /api/v1/status/buildinfo
• GET /api/v1/status/tsdb
• GET /api/v1/status/walreplay

admin

• POST & PUT /api/v1/admin/tsdb/snapshot
• POST & PUT /api/v1/admin/tsdb/delete_series
• POST & PUT /api/v1/admin/tsdb/clean_tombstones

[waynexia]

Close as completed