Prevent race between register and deregister requests by saving them
together in the local state on registration.
Also adds more cleaning in case of failure when registering services
/ checks.
Previously we were fixing up the token links directly on the *ACLToken returned by memdb. This invalidated some assumptions that a snapshot is immutable as well as potentially being able to cause a crash.
The fix here is to give the policy link fixing function copy on write semantics. When no fixes are necessary we can return the memdb object directly, otherwise we copy it and create a new list of links.
Eventually we might find a better way to keep those policy links in sync but for now this fixes the issue.
* Fix race condition in DNS when using cache
The healty node filtering was modifying the result from the cache, which
caused a crash when multiple queries were made to the same service
simultaneously.
We now copy the node slice before filtering to ensure we do not modify
the data stored in the cache.
* Fix wording in dns cache config doc
s/dns_max_age/cache_max_age/
This PR adds two features which will be useful for operators when ACLs are in use.
1. Tokens set in configuration files are now reloadable.
2. If `acl.enable_token_persistence` is set to `true` in the configuration, tokens set via the `v1/agent/token` endpoint are now persisted to disk and loaded when the agent starts (or during configuration reload)
Note that token persistence is opt-in so our users who do not want tokens on the local disk will see no change.
Some other secondary changes:
* Refactored a bunch of places where the replication token is retrieved from the token store. This token isn't just for replicating ACLs and now it is named accordingly.
* Allowed better paths in the `v1/agent/token/` API. Instead of paths like: `v1/agent/token/acl_replication_token` the path can now be just `v1/agent/token/replication`. The old paths remain to be valid.
* Added a couple new API functions to set tokens via the new paths. Deprecated the old ones and pointed to the new names. The names are also generally better and don't imply that what you are setting is for ACLs but rather are setting ACL tokens. There is a minor semantic difference there especially for the replication token as again, its no longer used only for ACL token/policy replication. The new functions will detect 404s and fallback to using the older token paths when talking to pre-1.4.3 agents.
* Docs updated to reflect the API additions and to show using the new endpoints.
* Updated the ACL CLI set-agent-tokens command to use the non-deprecated APIs.
This PR is based on #5366 and continues to centralise the tls configuration in order to be reloadable eventually!
This PR is another refactoring. No tests are changed, beyond calling other functions or cosmetic stuff. I added a bunch of tests, even though they might be redundant.
In order to be able to reload the TLS configuration, we need one way to generate the different configurations.
This PR introduces a `tlsutil.Configurator` which holds a `tlsutil.Config`. Afterwards it is responsible for rendering every `tls.Config`. In this particular PR I moved `IncomingHTTPSConfig`, `IncomingTLSConfig`, and `OutgoingTLSWrapper` into `tlsutil.Configurator`.
This PR is a pure refactoring - not a single feature added. And not a single test added. I only slightly modified existing tests as necessary.
Adds two new configuration parameters "dns_config.use_cache" and
"dns_config.cache_max_age" controlling how DNS requests use the agent
cache when querying servers.
* Add common blocking implementation details to docs
These come up over and over again with blocking query loops in our own code and third-party's. #5333 is possibly a case (unconfirmed) where "badly behaved" blocking clients cause issues, however since we've never explicitly documented these things it's not reasonable for third-party clients to have guessed that they are needed!
This hopefully gives us something to point to for the future.
It's a little wordy - happy to consider breaking some of the blocking stuff out of this page if we think it's appropriate but just wanted to quickly plaster over this gap in our docs for now.
* Update index.html.md
* Apply suggestions from code review
Co-Authored-By: banks <banks@banksco.de>
* Update index.html.md
* Update index.html.md
* Clearified monotonically
* Fixing formating
Chip Vaughn