* Add config, HTTP Basic Auth and TLS support to the generic write path.
- Move generic write path configuration to the config file
- Factor out config.TLSConfig -> tlf.Config translation
- Support TLSConfig for generic remote storage
- Rename Run to Start, and make it non-blocking.
- Dedupe code in httputil for TLS config.
- Make remote queue metrics global.
Switched to testing by way of the static_configs rather than
dns_sd_config parameter. Verified that the revised test both passes
without network access, and also still catches the bug it's supposed to
cover.
Verify that if the configs change, target groups are cleaned on
TargetManager.reload (rather than having old ones linger around, even if
they are no longer present in the configs).
This covers the bug fixed in #1907 -- I verified that by checking out
source from before that commit.
This is a start on #1906
Also, remove unused `providers` field in targetSet.
If the config file changes, we recreate all providers (by calling
`providersFromConfig`) and retrieve all targets anew from the newly
created providers. From that perspective, it cannot harm to clean up
the target group map in the targetSet. Not doing so (as it was the
case so far) keeps stale targets around. This mattered if an existing
key in the target group map was not overwritten in the initial fetch
of all targets from the providers. Examples where that mattered:
```
scrape_configs:
- job_name: "foo"
static_configs:
- targets: ["foo:9090"]
- targets: ["bar:9090"]
```
updated to:
```
scrape_configs:
- job_name: "foo"
static_configs:
- targets: ["foo:9090"]
```
`bar:9090` would still be monitored. (The static provider just
enumerates the target groups. If the number of target groups
decreases, the old ones stay around.
```
scrape_configs:
- job_name: "foo"
dns_sd_configs:
- names:
- "srv.name.one.example.org"
```
updated to:
```
scrape_configs:
- job_name: "foo"
dns_sd_configs:
- names:
- "srv.name.two.example.org"
```
Now both SRV records are still monitored. The SRV name is part of the
key in the target group map, thus the new one is just added and the
old ane stays around.
Obviously, this should have tests, and should have tests before, not
only for this case. This is the quick fix. I have created
https://github.com/prometheus/prometheus/issues/1906 to track test
creation.
Fixes https://github.com/prometheus/prometheus/issues/1610 .
0 is considered an invalid interval by time.NewTicker() and will cause a
panic if control reaches that point. Given the vagaries of timekeeping,
this may occasionally happen and make this test unstable.
