open-consul/acl/errors.go
Matt Keeler 99e0a124cb
New ACLs (#4791)
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.
2018-10-19 12:04:07 -04:00

73 lines
2 KiB
Go

package acl
import (
"errors"
"strings"
)
// These error constants define the standard ACL error types. The values
// must not be changed since the error values are sent via RPC calls
// from older clients and may not have the correct type.
const (
errNotFound = "ACL not found"
errRootDenied = "Cannot resolve root ACL"
errDisabled = "ACL support disabled"
errPermissionDenied = "Permission denied"
errInvalidParent = "Invalid Parent"
)
var (
// ErrNotFound indicates there is no matching ACL.
ErrNotFound = errors.New(errNotFound)
// ErrRootDenied is returned when attempting to resolve a root ACL.
ErrRootDenied = errors.New(errRootDenied)
// ErrDisabled is returned when ACL changes are not permitted since
// they are disabled.
ErrDisabled = errors.New(errDisabled)
// ErrPermissionDenied is returned when an ACL based rejection
// happens.
ErrPermissionDenied = PermissionDeniedError{}
// ErrInvalidParent is returned when a remotely resolve ACL
// token claims to have a non-root parent
ErrInvalidParent = errors.New(errInvalidParent)
)
// IsErrNotFound checks if the given error message is comparable to
// ErrNotFound.
func IsErrNotFound(err error) bool {
return err != nil && strings.Contains(err.Error(), errNotFound)
}
// IsErrRootDenied checks if the given error message is comparable to
// ErrRootDenied.
func IsErrRootDenied(err error) bool {
return err != nil && strings.Contains(err.Error(), errRootDenied)
}
// IsErrDisabled checks if the given error message is comparable to
// ErrDisabled.
func IsErrDisabled(err error) bool {
return err != nil && strings.Contains(err.Error(), errDisabled)
}
// IsErrPermissionDenied checks if the given error message is comparable
// to ErrPermissionDenied.
func IsErrPermissionDenied(err error) bool {
return err != nil && strings.Contains(err.Error(), errPermissionDenied)
}
type PermissionDeniedError struct {
Cause string
}
func (e PermissionDeniedError) Error() string {
if e.Cause != "" {
return errPermissionDenied + ": " + e.Cause
}
return errPermissionDenied
}