The logic employed for re-using the previously loaded scrape target was broken initially.
The commit cc0427897c tried to fix it, but the new logic
became too complex and fragile. So it is better to just remove this logic,
since the targets from temporarily broken file should be eventually loaded on next
attempts every -promscrape.fileSDCheckInterval
This also allows removing fragile hacks around __vm_filepath label.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3989
- Do not generate __meta_server label, since it is unavailable in Prometheus.
- Add a link to https://docs.victoriametrics.com/sd_configs.html#kuma_sd_configs to docs/CHANGELOG.md,
so users could click it and read the docs without the need to search the corresponding docs.
- Remove kumaTarget struct, since it is easier generating labels for discovered targets
directly from the response returned by Kuma. This simplifies the code.
- Store the generated labels for discovered targets inside atomic.Value. This allows reading them
from concurrent goroutines without the need to use mutex.
- Use synchronouse requests to Kuma instead of long polling, since there is a little sense
in the long polling when the Kuma server may return 304 Not Modified response every -promscrape.kumaSDCheckInterval.
- Remove -promscrape.kuma.waitTime command-line flag, since it is no longer needed when long polling isn't used.
- Set default value for -promscrape.kumaSDCheckInterval to 30s in order to be consistent with Prometheus.
- Remove unnecessary indirections for string literals, which are used only once, in order to improve code readability.
- Remove unused fields from discoveryRequest and discoveryResponse.
- Update tests.
- Document why fetch_timeout and refresh_interval options are missing in kuma_sd_config.
- Add docs to discoveryutils.RequestCallback and discoveryutils.ResponseCallback,
since these are public types.
Side notes: it is weird that Prometheus implementation for kuma_sd_configs sets `instance` label,
since usually this label is set by the Prometheus itself to __address__ after the relabeling phase.
See https://www.robustperception.io/life-of-a-label/
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3389
See https://github.com/prometheus/prometheus/issues/7919
and https://github.com/prometheus/prometheus/pull/8844
as a reference implementation in Prometheus
See the list of configs supported by Prometheus at f88a0a7d83/discovery/nomad/nomad.go (L76-L84)
- Removed "token" option. In can be set either via NOMAD_TOKEN env var or via `bearer_token` config option.
- Removed "scheme" option. It is automatically detected depending on whether the `tls_config` is set.
- Removed "services" and "tags" options, since they aren't supported by Prometheus.
- Added "region" option. If it is missing, then the region is read from NOMAD_REGION env var.
If this var is empty, then it is set to "global" in the same way as Nomad client does.
See 865ee8d37c/api/api.go (L297)
and 865ee8d37c/api/api.go (L555-L556)
- If the "server" option is missing, then it is read from NOMAD_ADDR in the same way
as Nomad client does - see 865ee8d37c/api/api.go (L294-L296)
This is a follow-up for 8aee209c53
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3367
- Remove undocumented `username` and `password` config options from `nomad_sd_config`.
TODO: probably, remove these options from `consul_sd_config` too?
These options exist there for backwards compatibility purposes.
- Add __meta_nomad_service_alloc_id and __meta_nomad_service_job_id meta-labels
These labels contain AllocID and JobID fields for the discovered Nomad services.
- Various typo fixes.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3367
Previously the `__address__` label could contain only `host:port` part of the target url,
while the scheme and metrics path were obtained from `__scheme__` and `__metrics_path__`
labels. Now it is possible to set the full url in `__address__` label.
This makes valid the following scrape config, which is frequently used by novice users:
scrape_configs:
- job_name: foo
static_configs:
- targets:
- http://host1/metrics1
- https://host2/metrics2
