open-consul/agent/consul/kvs_endpoint.go

300 lines
8.1 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/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 acl.Authorizer, 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 authz.KeyWritePrefix(dirEnt.Key, &authzContext) != acl.Allow {
return false, acl.ErrPermissionDenied
}
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 authz.KeyRead(dirEnt.Key, &authzContext) != acl.Allow {
return false, acl.ErrPermissionDenied
}
default:
var authzContext acl.AuthorizerContext
dirEnt.FillAuthzContext(&authzContext)
if authz.KeyWrite(dirEnt.Key, &authzContext) != acl.Allow {
return false, acl.ErrPermissionDenied
}
}
// 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 authz.KeyRead(args.Key, &authzContext) != acl.Allow {
return acl.ErrPermissionDenied
}
if ent == nil {
// 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 = 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 && authz.KeyList(args.Key, &authzContext) != acl.Allow {
return acl.ErrPermissionDenied
}
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
}
ent = FilterDirEnt(authz, 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 && authz.KeyList(args.Prefix, &authzContext) != acl.Allow {
return acl.ErrPermissionDenied
}
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
}
entries = FilterDirEnt(authz, 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
})
}