open-consul/agent/consul/kvs_endpoint.go
Dan Upton 989b22425c
Move ACLResolveResult into acl/resolver package (#13467)
Having this type live in the agent/consul package makes it difficult to
put anything that relies on token resolution (e.g. the new gRPC services)
in separate packages without introducing import cycles.

For example, if package foo imports agent/consul for the ACLResolveResult
type it means that agent/consul cannot import foo to register its service.

We've previously worked around this by wrapping the ACLResolver to
"downgrade" its return type to an acl.Authorizer - aside from the
added complexity, this also loses the resolved identity information.

In the future, we may want to move the whole ACLResolver into the
acl/resolver package. For now, putting the result type there at least,
fixes the immediate import cycle issues.
2022-06-17 10:24:43 +01:00

305 lines
8.3 KiB
Go

package consul
import (
"fmt"
"strings"
"time"
"github.com/armon/go-metrics"
"github.com/armon/go-metrics/prometheus"
"github.com/hashicorp/go-hclog"
"github.com/hashicorp/go-memdb"
"github.com/hashicorp/consul/acl"
"github.com/hashicorp/consul/acl/resolver"
"github.com/hashicorp/consul/agent/consul/state"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/api"
)
var KVSummaries = []prometheus.SummaryDefinition{
{
Name: []string{"kvs", "apply"},
Help: "Measures the time it takes to complete an update to the KV store.",
},
}
// KVS endpoint is used to manipulate the Key-Value store
type KVS struct {
srv *Server
logger hclog.Logger
}
// preApply does all the verification of a KVS update that is performed BEFORE
// we submit as a Raft log entry. This includes enforcing the lock delay which
// must only be done on the leader.
func kvsPreApply(logger hclog.Logger, srv *Server, authz resolver.Result, op api.KVOp, dirEnt *structs.DirEntry) (bool, error) {
// Verify the entry.
if dirEnt.Key == "" && op != api.KVDeleteTree {
return false, fmt.Errorf("Must provide key")
}
// Apply the ACL policy if any.
switch op {
case api.KVDeleteTree:
var authzContext acl.AuthorizerContext
dirEnt.FillAuthzContext(&authzContext)
if err := authz.ToAllowAuthorizer().KeyWritePrefixAllowed(dirEnt.Key, &authzContext); err != nil {
return false, err
}
case api.KVGet, api.KVGetTree:
// Filtering for GETs is done on the output side.
case api.KVCheckSession, api.KVCheckIndex:
// These could reveal information based on the outcome
// of the transaction, and they operate on individual
// keys so we check them here.
var authzContext acl.AuthorizerContext
dirEnt.FillAuthzContext(&authzContext)
if err := authz.ToAllowAuthorizer().KeyReadAllowed(dirEnt.Key, &authzContext); err != nil {
return false, err
}
default:
var authzContext acl.AuthorizerContext
dirEnt.FillAuthzContext(&authzContext)
if err := authz.ToAllowAuthorizer().KeyWriteAllowed(dirEnt.Key, &authzContext); err != nil {
return false, err
}
}
// If this is a lock, we must check for a lock-delay. Since lock-delay
// is based on wall-time, each peer would expire the lock-delay at a slightly
// different time. This means the enforcement of lock-delay cannot be done
// after the raft log is committed as it would lead to inconsistent FSMs.
// Instead, the lock-delay must be enforced before commit. This means that
// only the wall-time of the leader node is used, preventing any inconsistencies.
if op == api.KVLock {
state := srv.fsm.State()
expires := state.KVSLockDelay(dirEnt.Key, &dirEnt.EnterpriseMeta)
if expires.After(time.Now()) {
logger.Warn("Rejecting lock of key due to lock-delay",
"key", dirEnt.Key,
"expire_time", expires.String(),
)
return false, nil
}
}
return true, nil
}
// Apply is used to apply a KVS update request to the data store.
func (k *KVS) Apply(args *structs.KVSRequest, reply *bool) error {
if done, err := k.srv.ForwardRPC("KVS.Apply", args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"kvs", "apply"}, time.Now())
// Perform the pre-apply checks.
authz, err := k.srv.ResolveTokenAndDefaultMeta(args.Token, &args.DirEnt.EnterpriseMeta, nil)
if err != nil {
return err
}
if err := k.srv.validateEnterpriseRequest(&args.DirEnt.EnterpriseMeta, true); err != nil {
return err
}
ok, err := kvsPreApply(k.logger, k.srv, authz, args.Op, &args.DirEnt)
if err != nil {
return err
}
if !ok {
*reply = false
return nil
}
// Apply the update.
resp, err := k.srv.raftApply(structs.KVSRequestType, args)
if err != nil {
return fmt.Errorf("raft apply failed: %w", err)
}
// Check if the return type is a bool.
if respBool, ok := resp.(bool); ok {
*reply = respBool
}
return nil
}
// Get is used to lookup a single key.
func (k *KVS) Get(args *structs.KeyRequest, reply *structs.IndexedDirEntries) error {
if done, err := k.srv.ForwardRPC("KVS.Get", args, reply); done {
return err
}
var authzContext acl.AuthorizerContext
authz, err := k.srv.ResolveTokenAndDefaultMeta(args.Token, &args.EnterpriseMeta, &authzContext)
if err != nil {
return err
}
if err := k.srv.validateEnterpriseRequest(&args.EnterpriseMeta, false); err != nil {
return err
}
return k.srv.blockingQuery(
&args.QueryOptions,
&reply.QueryMeta,
func(ws memdb.WatchSet, state *state.Store) error {
index, ent, err := state.KVSGet(ws, args.Key, &args.EnterpriseMeta)
if err != nil {
return err
}
if err := authz.ToAllowAuthorizer().KeyReadAllowed(args.Key, &authzContext); err != nil {
return err
}
if ent == nil {
reply.Index = index
reply.Entries = nil
return errNotFound
}
reply.Index = ent.ModifyIndex
reply.Entries = structs.DirEntries{ent}
return nil
})
}
// List is used to list all keys with a given prefix.
func (k *KVS) List(args *structs.KeyRequest, reply *structs.IndexedDirEntries) error {
if done, err := k.srv.ForwardRPC("KVS.List", args, reply); done {
return err
}
var authzContext acl.AuthorizerContext
authz, err := k.srv.ResolveTokenAndDefaultMeta(args.Token, &args.EnterpriseMeta, &authzContext)
if err != nil {
return err
}
if err := k.srv.validateEnterpriseRequest(&args.EnterpriseMeta, false); err != nil {
return err
}
if k.srv.config.ACLEnableKeyListPolicy {
if err := authz.ToAllowAuthorizer().KeyListAllowed(args.Key, &authzContext); err != nil {
return err
}
}
return k.srv.blockingQuery(
&args.QueryOptions,
&reply.QueryMeta,
func(ws memdb.WatchSet, state *state.Store) error {
index, ent, err := state.KVSList(ws, args.Key, &args.EnterpriseMeta)
if err != nil {
return err
}
total := len(ent)
ent = FilterDirEnt(authz, ent)
reply.QueryMeta.ResultsFilteredByACLs = total != len(ent)
if len(ent) == 0 {
// Must provide non-zero index to prevent blocking
// Index 1 is impossible anyways (due to Raft internals)
if index == 0 {
reply.Index = 1
} else {
reply.Index = index
}
reply.Entries = nil
} else {
reply.Index = index
reply.Entries = ent
}
return nil
})
}
// ListKeys is used to list all keys with a given prefix to a separator.
// An optional separator may be specified, which can be used to slice off a part
// of the response so that only a subset of the prefix is returned. In this
// mode, the keys which are omitted are still counted in the returned index.
func (k *KVS) ListKeys(args *structs.KeyListRequest, reply *structs.IndexedKeyList) error {
if done, err := k.srv.ForwardRPC("KVS.ListKeys", args, reply); done {
return err
}
var authzContext acl.AuthorizerContext
authz, err := k.srv.ResolveTokenAndDefaultMeta(args.Token, &args.EnterpriseMeta, &authzContext)
if err != nil {
return err
}
if err := k.srv.validateEnterpriseRequest(&args.EnterpriseMeta, false); err != nil {
return err
}
if k.srv.config.ACLEnableKeyListPolicy {
if err := authz.ToAllowAuthorizer().KeyListAllowed(args.Prefix, &authzContext); err != nil {
return err
}
}
return k.srv.blockingQuery(
&args.QueryOptions,
&reply.QueryMeta,
func(ws memdb.WatchSet, state *state.Store) error {
index, entries, err := state.KVSList(ws, args.Prefix, &args.EnterpriseMeta)
if err != nil {
return err
}
// Must provide non-zero index to prevent blocking
// Index 1 is impossible anyways (due to Raft internals)
if index == 0 {
reply.Index = 1
} else {
reply.Index = index
}
total := len(entries)
entries = FilterDirEnt(authz, entries)
reply.QueryMeta.ResultsFilteredByACLs = total != len(entries)
// Collect the keys from the filtered entries
prefixLen := len(args.Prefix)
sepLen := len(args.Seperator)
var keys []string
seen := make(map[string]bool)
for _, e := range entries {
// Always accumulate if no separator provided
if sepLen == 0 {
keys = append(keys, e.Key)
continue
}
// Parse and de-duplicate the returned keys based on the
// key separator, if provided.
after := e.Key[prefixLen:]
sepIdx := strings.Index(after, args.Seperator)
if sepIdx > -1 {
key := e.Key[:prefixLen+sepIdx+sepLen]
if ok := seen[key]; !ok {
keys = append(keys, key)
seen[key] = true
}
} else {
keys = append(keys, e.Key)
}
}
reply.Keys = keys
return nil
})
}