* Renamed structs.IntentionWildcard to structs.WildcardSpecifier
* Refactor ACL Config
Get rid of remnants of enterprise only renaming.
Add a WildcardName field for specifying what string should be used to indicate a wildcard.
* Add wildcard support in the ACL package
For read operations they can call anyAllowed to determine if any read access to the given resource would be granted.
For write operations they can call allAllowed to ensure that write access is granted to everything.
* Make v1/agent/connect/authorize namespace aware
* Update intention ACL enforcement
This also changes how intention:read is granted. Before the Intention.List RPC would allow viewing an intention if the token had intention:read on the destination. However Intention.Match allowed viewing if access was allowed for either the source or dest side. Now Intention.List and Intention.Get fall in line with Intention.Matches previous behavior.
Due to this being done a few different places ACL enforcement for a singular intention is now done with the CanRead and CanWrite methods on the intention itself.
* Refactor Intention.Apply to make things easier to follow.
This PR is almost a complete rewrite of the ACL system within Consul. It brings the features more in line with other HashiCorp products. Obviously there is quite a bit left to do here but most of it is related docs, testing and finishing the last few commands in the CLI. I will update the PR description and check off the todos as I finish them over the next few days/week.
Description
At a high level this PR is mainly to split ACL tokens from Policies and to split the concepts of Authorization from Identities. A lot of this PR is mostly just to support CRUD operations on ACLTokens and ACLPolicies. These in and of themselves are not particularly interesting. The bigger conceptual changes are in how tokens get resolved, how backwards compatibility is handled and the separation of policy from identity which could lead the way to allowing for alternative identity providers.
On the surface and with a new cluster the ACL system will look very similar to that of Nomads. Both have tokens and policies. Both have local tokens. The ACL management APIs for both are very similar. I even ripped off Nomad's ACL bootstrap resetting procedure. There are a few key differences though.
Nomad requires token and policy replication where Consul only requires policy replication with token replication being opt-in. In Consul local tokens only work with token replication being enabled though.
All policies in Nomad are globally applicable. In Consul all policies are stored and replicated globally but can be scoped to a subset of the datacenters. This allows for more granular access management.
Unlike Nomad, Consul has legacy baggage in the form of the original ACL system. The ramifications of this are:
A server running the new system must still support other clients using the legacy system.
A client running the new system must be able to use the legacy RPCs when the servers in its datacenter are running the legacy system.
The primary ACL DC's servers running in legacy mode needs to be a gate that keeps everything else in the entire multi-DC cluster running in legacy mode.
So not only does this PR implement the new ACL system but has a legacy mode built in for when the cluster isn't ready for new ACLs. Also detecting that new ACLs can be used is automatic and requires no configuration on the part of administrators. This process is detailed more in the "Transitioning from Legacy to New ACL Mode" section below.
