open-nomad/api/allocations.go
Mahmood Ali b77fd8654b cli: recover from client ACL lookup failures
This fixes a bug in the CLI handling of node lookup failures when
querying allocation and FS endpoints.

Allocation and FS endpoint are handled by the client; one can query the
relevant client directly, or query a server to have it forwarded
transparently to relevant client.  Querying the client directly is
benefecial to avoid loading servers with IO.

As an optimization, the CLI attempts to query the client directly, but
then falls back to using server forwarding path if it encounters network
or connection errors (e.g. clients are locked down or in a separate
inaccessible network).

Here, we fix a bug where if the CLI fails to find to lookup the client
details because it lacks ACL capability or other unexpected reasons, the
CLI will not go through fallback path.
2019-10-04 11:23:59 -04:00

602 lines
16 KiB
Go

package api
import (
"context"
"encoding/json"
"errors"
"fmt"
"io"
"net"
"sort"
"strconv"
"sync"
"time"
"github.com/gorilla/websocket"
)
var (
// NodeDownErr marks an operation as not able to complete since the node is
// down.
NodeDownErr = fmt.Errorf("node down")
)
const (
AllocDesiredStatusRun = "run" // Allocation should run
AllocDesiredStatusStop = "stop" // Allocation should stop
AllocDesiredStatusEvict = "evict" // Allocation should stop, and was evicted
)
const (
AllocClientStatusPending = "pending"
AllocClientStatusRunning = "running"
AllocClientStatusComplete = "complete"
AllocClientStatusFailed = "failed"
AllocClientStatusLost = "lost"
)
// Allocations is used to query the alloc-related endpoints.
type Allocations struct {
client *Client
}
// Allocations returns a handle on the allocs endpoints.
func (c *Client) Allocations() *Allocations {
return &Allocations{client: c}
}
// List returns a list of all of the allocations.
func (a *Allocations) List(q *QueryOptions) ([]*AllocationListStub, *QueryMeta, error) {
var resp []*AllocationListStub
qm, err := a.client.query("/v1/allocations", &resp, q)
if err != nil {
return nil, nil, err
}
sort.Sort(AllocIndexSort(resp))
return resp, qm, nil
}
func (a *Allocations) PrefixList(prefix string) ([]*AllocationListStub, *QueryMeta, error) {
return a.List(&QueryOptions{Prefix: prefix})
}
// Info is used to retrieve a single allocation.
func (a *Allocations) Info(allocID string, q *QueryOptions) (*Allocation, *QueryMeta, error) {
var resp Allocation
qm, err := a.client.query("/v1/allocation/"+allocID, &resp, q)
if err != nil {
return nil, nil, err
}
return &resp, qm, nil
}
// Exec is used to execute a command inside a running task. The command is to run inside
// the task environment.
//
// The parameters are:
// * ctx: context to set deadlines or timeout
// * allocation: the allocation to execute command inside
// * task: the task's name to execute command in
// * tty: indicates whether to start a pseudo-tty for the command
// * stdin, stdout, stderr: the std io to pass to command.
// If tty is true, then streams need to point to a tty that's alive for the whole process
// * terminalSizeCh: A channel to send new tty terminal sizes
//
// The call blocks until command terminates (or an error occurs), and returns the exit code.
func (a *Allocations) Exec(ctx context.Context,
alloc *Allocation, task string, tty bool, command []string,
stdin io.Reader, stdout, stderr io.Writer,
terminalSizeCh <-chan TerminalSize, q *QueryOptions) (exitCode int, err error) {
ctx, cancelFn := context.WithCancel(ctx)
defer cancelFn()
errCh := make(chan error, 4)
sender, output := a.execFrames(ctx, alloc, task, tty, command, errCh, q)
select {
case err := <-errCh:
return -2, err
default:
}
// Errors resulting from sending input (in goroutines) are silently dropped.
// To mitigate this, extra care is needed to distinguish between actual send errors
// and from send errors due to command terminating and our race to detect failures.
// If we have an actual network failure or send a bad input, we'd get an
// error in the reading side of websocket.
go func() {
bytes := make([]byte, 2048)
for {
if ctx.Err() != nil {
return
}
input := ExecStreamingInput{Stdin: &ExecStreamingIOOperation{}}
n, err := stdin.Read(bytes)
// always send data if we read some
if n != 0 {
input.Stdin.Data = bytes[:n]
sender(&input)
}
// then handle error
if err == io.EOF {
// if n != 0, send data and we'll get n = 0 on next read
if n == 0 {
input.Stdin.Close = true
sender(&input)
return
}
} else if err != nil {
errCh <- err
return
}
}
}()
// forwarding terminal size
go func() {
for {
resizeInput := ExecStreamingInput{}
select {
case <-ctx.Done():
return
case size, ok := <-terminalSizeCh:
if !ok {
return
}
resizeInput.TTYSize = &size
sender(&resizeInput)
}
}
}()
// send a heartbeat every 10 seconds
go func() {
for {
select {
case <-ctx.Done():
return
// heartbeat message
case <-time.After(10 * time.Second):
sender(&execStreamingInputHeartbeat)
}
}
}()
for {
select {
case err := <-errCh:
// drop websocket code, not relevant to user
if wsErr, ok := err.(*websocket.CloseError); ok && wsErr.Text != "" {
return -2, errors.New(wsErr.Text)
}
return -2, err
case <-ctx.Done():
return -2, ctx.Err()
case frame, ok := <-output:
if !ok {
return -2, errors.New("disconnected without receiving the exit code")
}
switch {
case frame.Stdout != nil:
if len(frame.Stdout.Data) != 0 {
stdout.Write(frame.Stdout.Data)
}
// don't really do anything if stdout is closing
case frame.Stderr != nil:
if len(frame.Stderr.Data) != 0 {
stderr.Write(frame.Stderr.Data)
}
// don't really do anything if stderr is closing
case frame.Exited && frame.Result != nil:
return frame.Result.ExitCode, nil
default:
// noop - heartbeat
}
}
}
}
func (a *Allocations) execFrames(ctx context.Context, alloc *Allocation, task string, tty bool, command []string,
errCh chan<- error, q *QueryOptions) (sendFn func(*ExecStreamingInput) error, output <-chan *ExecStreamingOutput) {
nodeClient, _ := a.client.GetNodeClientWithTimeout(alloc.NodeID, ClientConnTimeout, q)
if q == nil {
q = &QueryOptions{}
}
if q.Params == nil {
q.Params = make(map[string]string)
}
commandBytes, err := json.Marshal(command)
if err != nil {
errCh <- fmt.Errorf("failed to marshal command: %s", err)
return nil, nil
}
q.Params["tty"] = strconv.FormatBool(tty)
q.Params["task"] = task
q.Params["command"] = string(commandBytes)
reqPath := fmt.Sprintf("/v1/client/allocation/%s/exec", alloc.ID)
var conn *websocket.Conn
if nodeClient != nil {
conn, _, err = nodeClient.websocket(reqPath, q)
if _, ok := err.(net.Error); err != nil && !ok {
errCh <- err
return nil, nil
}
}
if conn == nil {
conn, _, err = a.client.websocket(reqPath, q)
if err != nil {
errCh <- err
return nil, nil
}
}
// Create the output channel
frames := make(chan *ExecStreamingOutput, 10)
go func() {
defer conn.Close()
for ctx.Err() == nil {
// Decode the next frame
var frame ExecStreamingOutput
err := conn.ReadJSON(&frame)
if websocket.IsCloseError(err, websocket.CloseNormalClosure) {
close(frames)
return
} else if err != nil {
errCh <- err
return
}
frames <- &frame
}
}()
var sendLock sync.Mutex
send := func(v *ExecStreamingInput) error {
sendLock.Lock()
defer sendLock.Unlock()
return conn.WriteJSON(v)
}
return send, frames
}
func (a *Allocations) Stats(alloc *Allocation, q *QueryOptions) (*AllocResourceUsage, error) {
var resp AllocResourceUsage
path := fmt.Sprintf("/v1/client/allocation/%s/stats", alloc.ID)
_, err := a.client.query(path, &resp, q)
return &resp, err
}
func (a *Allocations) GC(alloc *Allocation, q *QueryOptions) error {
nodeClient, err := a.client.GetNodeClient(alloc.NodeID, q)
if err != nil {
return err
}
var resp struct{}
_, err = nodeClient.query("/v1/client/allocation/"+alloc.ID+"/gc", &resp, nil)
return err
}
func (a *Allocations) Restart(alloc *Allocation, taskName string, q *QueryOptions) error {
req := AllocationRestartRequest{
TaskName: taskName,
}
var resp struct{}
_, err := a.client.putQuery("/v1/client/allocation/"+alloc.ID+"/restart", &req, &resp, q)
return err
}
func (a *Allocations) Stop(alloc *Allocation, q *QueryOptions) (*AllocStopResponse, error) {
var resp AllocStopResponse
_, err := a.client.putQuery("/v1/allocation/"+alloc.ID+"/stop", nil, &resp, q)
return &resp, err
}
// AllocStopResponse is the response to an `AllocStopRequest`
type AllocStopResponse struct {
// EvalID is the id of the follow up evalution for the rescheduled alloc.
EvalID string
WriteMeta
}
func (a *Allocations) Signal(alloc *Allocation, q *QueryOptions, task, signal string) error {
nodeClient, err := a.client.GetNodeClient(alloc.NodeID, q)
if err != nil {
return err
}
req := AllocSignalRequest{
Signal: signal,
Task: task,
}
var resp GenericResponse
_, err = nodeClient.putQuery("/v1/client/allocation/"+alloc.ID+"/signal", &req, &resp, q)
return err
}
// Allocation is used for serialization of allocations.
type Allocation struct {
ID string
Namespace string
EvalID string
Name string
NodeID string
NodeName string
JobID string
Job *Job
TaskGroup string
Resources *Resources
TaskResources map[string]*Resources
AllocatedResources *AllocatedResources
Services map[string]string
Metrics *AllocationMetric
DesiredStatus string
DesiredDescription string
DesiredTransition DesiredTransition
ClientStatus string
ClientDescription string
TaskStates map[string]*TaskState
DeploymentID string
DeploymentStatus *AllocDeploymentStatus
FollowupEvalID string
PreviousAllocation string
NextAllocation string
RescheduleTracker *RescheduleTracker
PreemptedAllocations []string
PreemptedByAllocation string
CreateIndex uint64
ModifyIndex uint64
AllocModifyIndex uint64
CreateTime int64
ModifyTime int64
}
// AllocationMetric is used to deserialize allocation metrics.
type AllocationMetric struct {
NodesEvaluated int
NodesFiltered int
NodesAvailable map[string]int
ClassFiltered map[string]int
ConstraintFiltered map[string]int
NodesExhausted int
ClassExhausted map[string]int
DimensionExhausted map[string]int
QuotaExhausted []string
// Deprecated, replaced with ScoreMetaData
Scores map[string]float64
AllocationTime time.Duration
CoalescedFailures int
ScoreMetaData []*NodeScoreMeta
}
// NodeScoreMeta is used to serialize node scoring metadata
// displayed in the CLI during verbose mode
type NodeScoreMeta struct {
NodeID string
Scores map[string]float64
NormScore float64
}
// AllocationListStub is used to return a subset of an allocation
// during list operations.
type AllocationListStub struct {
ID string
EvalID string
Name string
Namespace string
NodeID string
NodeName string
JobID string
JobType string
JobVersion uint64
TaskGroup string
DesiredStatus string
DesiredDescription string
ClientStatus string
ClientDescription string
TaskStates map[string]*TaskState
DeploymentStatus *AllocDeploymentStatus
FollowupEvalID string
RescheduleTracker *RescheduleTracker
PreemptedAllocations []string
PreemptedByAllocation string
CreateIndex uint64
ModifyIndex uint64
CreateTime int64
ModifyTime int64
}
// AllocDeploymentStatus captures the status of the allocation as part of the
// deployment. This can include things like if the allocation has been marked as
// healthy.
type AllocDeploymentStatus struct {
Healthy *bool
Timestamp time.Time
Canary bool
ModifyIndex uint64
}
type AllocatedResources struct {
Tasks map[string]*AllocatedTaskResources
Shared AllocatedSharedResources
}
type AllocatedTaskResources struct {
Cpu AllocatedCpuResources
Memory AllocatedMemoryResources
Networks []*NetworkResource
}
type AllocatedSharedResources struct {
DiskMB int64
Networks []*NetworkResource
}
type AllocatedCpuResources struct {
CpuShares int64
}
type AllocatedMemoryResources struct {
MemoryMB int64
}
// AllocIndexSort reverse sorts allocs by CreateIndex.
type AllocIndexSort []*AllocationListStub
func (a AllocIndexSort) Len() int {
return len(a)
}
func (a AllocIndexSort) Less(i, j int) bool {
return a[i].CreateIndex > a[j].CreateIndex
}
func (a AllocIndexSort) Swap(i, j int) {
a[i], a[j] = a[j], a[i]
}
// RescheduleInfo is used to calculate remaining reschedule attempts
// according to the given time and the task groups reschedule policy
func (a Allocation) RescheduleInfo(t time.Time) (int, int) {
var reschedulePolicy *ReschedulePolicy
for _, tg := range a.Job.TaskGroups {
if *tg.Name == a.TaskGroup {
reschedulePolicy = tg.ReschedulePolicy
}
}
if reschedulePolicy == nil {
return 0, 0
}
availableAttempts := *reschedulePolicy.Attempts
interval := *reschedulePolicy.Interval
attempted := 0
// Loop over reschedule tracker to find attempts within the restart policy's interval
if a.RescheduleTracker != nil && availableAttempts > 0 && interval > 0 {
for j := len(a.RescheduleTracker.Events) - 1; j >= 0; j-- {
lastAttempt := a.RescheduleTracker.Events[j].RescheduleTime
timeDiff := t.UTC().UnixNano() - lastAttempt
if timeDiff < interval.Nanoseconds() {
attempted += 1
}
}
}
return attempted, availableAttempts
}
type AllocationRestartRequest struct {
TaskName string
}
type AllocSignalRequest struct {
Task string
Signal string
}
// GenericResponse is used to respond to a request where no
// specific response information is needed.
type GenericResponse struct {
WriteMeta
}
// RescheduleTracker encapsulates previous reschedule events
type RescheduleTracker struct {
Events []*RescheduleEvent
}
// RescheduleEvent is used to keep track of previous attempts at rescheduling an allocation
type RescheduleEvent struct {
// RescheduleTime is the timestamp of a reschedule attempt
RescheduleTime int64
// PrevAllocID is the ID of the previous allocation being restarted
PrevAllocID string
// PrevNodeID is the node ID of the previous allocation
PrevNodeID string
}
// DesiredTransition is used to mark an allocation as having a desired state
// transition. This information can be used by the scheduler to make the
// correct decision.
type DesiredTransition struct {
// Migrate is used to indicate that this allocation should be stopped and
// migrated to another node.
Migrate *bool
// Reschedule is used to indicate that this allocation is eligible to be
// rescheduled.
Reschedule *bool
}
// ShouldMigrate returns whether the transition object dictates a migration.
func (d DesiredTransition) ShouldMigrate() bool {
return d.Migrate != nil && *d.Migrate
}
// ExecStreamingIOOperation represents a stream write operation: either appending data or close (exclusively)
type ExecStreamingIOOperation struct {
Data []byte `json:"data,omitempty"`
Close bool `json:"close,omitempty"`
}
// TerminalSize represents the size of the terminal
type TerminalSize struct {
Height int `json:"height,omitempty"`
Width int `json:"width,omitempty"`
}
var execStreamingInputHeartbeat = ExecStreamingInput{}
// ExecStreamingInput represents user input to be sent to nomad exec handler.
//
// At most one field should be set.
type ExecStreamingInput struct {
Stdin *ExecStreamingIOOperation `json:"stdin,omitempty"`
TTYSize *TerminalSize `json:"tty_size,omitempty"`
}
// ExecStreamingExitResults captures the exit code of just completed nomad exec command
type ExecStreamingExitResult struct {
ExitCode int `json:"exit_code"`
}
// ExecStreamingInput represents an output streaming entity, e.g. stdout/stderr update or termination
//
// At most one of these fields should be set: `Stdout`, `Stderr`, or `Result`.
// If `Exited` is true, then `Result` is non-nil, and other fields are nil.
type ExecStreamingOutput struct {
Stdout *ExecStreamingIOOperation `json:"stdout,omitempty"`
Stderr *ExecStreamingIOOperation `json:"stderr,omitempty"`
Exited bool `json:"exited,omitempty"`
Result *ExecStreamingExitResult `json:"result,omitempty"`
}