open-nomad/api/api.go
Mahmood Ali 09931bcdce add api support for nomad exec
Adds nomad exec support in our API, by hitting the websocket endpoint.

We introduce API structs that correspond to the drivers streaming exec structs.

For creating the websocket connection, we reuse the transport setting from api
http client.
2019-05-09 16:49:08 -04:00

891 lines
22 KiB
Go

package api
import (
"bytes"
"compress/gzip"
"crypto/tls"
"encoding/json"
"fmt"
"io"
"net"
"net/http"
"net/url"
"os"
"strconv"
"strings"
"time"
"github.com/gorilla/websocket"
cleanhttp "github.com/hashicorp/go-cleanhttp"
rootcerts "github.com/hashicorp/go-rootcerts"
)
var (
// ClientConnTimeout is the timeout applied when attempting to contact a
// client directly before switching to a connection through the Nomad
// server.
ClientConnTimeout = 1 * time.Second
)
// QueryOptions are used to parametrize a query
type QueryOptions struct {
// Providing a datacenter overwrites the region provided
// by the Config
Region string
// Namespace is the target namespace for the query.
Namespace string
// AllowStale allows any Nomad server (non-leader) to service
// a read. This allows for lower latency and higher throughput
AllowStale bool
// WaitIndex is used to enable a blocking query. Waits
// until the timeout or the next index is reached
WaitIndex uint64
// WaitTime is used to bound the duration of a wait.
// Defaults to that of the Config, but can be overridden.
WaitTime time.Duration
// If set, used as prefix for resource list searches
Prefix string
// Set HTTP parameters on the query.
Params map[string]string
// AuthToken is the secret ID of an ACL token
AuthToken string
}
// WriteOptions are used to parametrize a write
type WriteOptions struct {
// Providing a datacenter overwrites the region provided
// by the Config
Region string
// Namespace is the target namespace for the write.
Namespace string
// AuthToken is the secret ID of an ACL token
AuthToken string
}
// QueryMeta is used to return meta data about a query
type QueryMeta struct {
// LastIndex. This can be used as a WaitIndex to perform
// a blocking query
LastIndex uint64
// Time of last contact from the leader for the
// server servicing the request
LastContact time.Duration
// Is there a known leader
KnownLeader bool
// How long did the request take
RequestTime time.Duration
}
// WriteMeta is used to return meta data about a write
type WriteMeta struct {
// LastIndex. This can be used as a WaitIndex to perform
// a blocking query
LastIndex uint64
// How long did the request take
RequestTime time.Duration
}
// HttpBasicAuth is used to authenticate http client with HTTP Basic Authentication
type HttpBasicAuth struct {
// Username to use for HTTP Basic Authentication
Username string
// Password to use for HTTP Basic Authentication
Password string
}
// Config is used to configure the creation of a client
type Config struct {
// Address is the address of the Nomad agent
Address string
// Region to use. If not provided, the default agent region is used.
Region string
// SecretID to use. This can be overwritten per request.
SecretID string
// Namespace to use. If not provided the default namespace is used.
Namespace string
// httpClient is the client to use. Default will be used if not provided.
httpClient *http.Client
// HttpAuth is the auth info to use for http access.
HttpAuth *HttpBasicAuth
// WaitTime limits how long a Watch will block. If not provided,
// the agent default values will be used.
WaitTime time.Duration
// TLSConfig provides the various TLS related configurations for the http
// client
TLSConfig *TLSConfig
}
// ClientConfig copies the configuration with a new client address, region, and
// whether the client has TLS enabled.
func (c *Config) ClientConfig(region, address string, tlsEnabled bool) *Config {
scheme := "http"
if tlsEnabled {
scheme = "https"
}
defaultConfig := DefaultConfig()
config := &Config{
Address: fmt.Sprintf("%s://%s", scheme, address),
Region: region,
Namespace: c.Namespace,
httpClient: defaultConfig.httpClient,
SecretID: c.SecretID,
HttpAuth: c.HttpAuth,
WaitTime: c.WaitTime,
TLSConfig: c.TLSConfig.Copy(),
}
// Update the tls server name for connecting to a client
if tlsEnabled && config.TLSConfig != nil {
config.TLSConfig.TLSServerName = fmt.Sprintf("client.%s.nomad", region)
}
return config
}
// TLSConfig contains the parameters needed to configure TLS on the HTTP client
// used to communicate with Nomad.
type TLSConfig struct {
// CACert is the path to a PEM-encoded CA cert file to use to verify the
// Nomad server SSL certificate.
CACert string
// CAPath is the path to a directory of PEM-encoded CA cert files to verify
// the Nomad server SSL certificate.
CAPath string
// ClientCert is the path to the certificate for Nomad communication
ClientCert string
// ClientKey is the path to the private key for Nomad communication
ClientKey string
// TLSServerName, if set, is used to set the SNI host when connecting via
// TLS.
TLSServerName string
// Insecure enables or disables SSL verification
Insecure bool
}
func (t *TLSConfig) Copy() *TLSConfig {
if t == nil {
return nil
}
nt := new(TLSConfig)
*nt = *t
return nt
}
// DefaultConfig returns a default configuration for the client
func DefaultConfig() *Config {
config := &Config{
Address: "http://127.0.0.1:4646",
httpClient: cleanhttp.DefaultClient(),
TLSConfig: &TLSConfig{},
}
transport := config.httpClient.Transport.(*http.Transport)
transport.TLSHandshakeTimeout = 10 * time.Second
transport.TLSClientConfig = &tls.Config{
MinVersion: tls.VersionTLS12,
}
if addr := os.Getenv("NOMAD_ADDR"); addr != "" {
config.Address = addr
}
if v := os.Getenv("NOMAD_REGION"); v != "" {
config.Region = v
}
if v := os.Getenv("NOMAD_NAMESPACE"); v != "" {
config.Namespace = v
}
if auth := os.Getenv("NOMAD_HTTP_AUTH"); auth != "" {
var username, password string
if strings.Contains(auth, ":") {
split := strings.SplitN(auth, ":", 2)
username = split[0]
password = split[1]
} else {
username = auth
}
config.HttpAuth = &HttpBasicAuth{
Username: username,
Password: password,
}
}
// Read TLS specific env vars
if v := os.Getenv("NOMAD_CACERT"); v != "" {
config.TLSConfig.CACert = v
}
if v := os.Getenv("NOMAD_CAPATH"); v != "" {
config.TLSConfig.CAPath = v
}
if v := os.Getenv("NOMAD_CLIENT_CERT"); v != "" {
config.TLSConfig.ClientCert = v
}
if v := os.Getenv("NOMAD_CLIENT_KEY"); v != "" {
config.TLSConfig.ClientKey = v
}
if v := os.Getenv("NOMAD_SKIP_VERIFY"); v != "" {
if insecure, err := strconv.ParseBool(v); err == nil {
config.TLSConfig.Insecure = insecure
}
}
if v := os.Getenv("NOMAD_TOKEN"); v != "" {
config.SecretID = v
}
return config
}
// SetTimeout is used to place a timeout for connecting to Nomad. A negative
// duration is ignored, a duration of zero means no timeout, and any other value
// will add a timeout.
func (c *Config) SetTimeout(t time.Duration) error {
if c == nil {
return fmt.Errorf("nil config")
} else if c.httpClient == nil {
return fmt.Errorf("nil HTTP client")
} else if c.httpClient.Transport == nil {
return fmt.Errorf("nil HTTP client transport")
}
// Apply a timeout.
if t.Nanoseconds() >= 0 {
transport, ok := c.httpClient.Transport.(*http.Transport)
if !ok {
return fmt.Errorf("unexpected HTTP transport: %T", c.httpClient.Transport)
}
transport.DialContext = (&net.Dialer{
Timeout: t,
KeepAlive: 30 * time.Second,
}).DialContext
}
return nil
}
// ConfigureTLS applies a set of TLS configurations to the the HTTP client.
func (c *Config) ConfigureTLS() error {
if c.TLSConfig == nil {
return nil
}
if c.httpClient == nil {
return fmt.Errorf("config HTTP Client must be set")
}
var clientCert tls.Certificate
foundClientCert := false
if c.TLSConfig.ClientCert != "" || c.TLSConfig.ClientKey != "" {
if c.TLSConfig.ClientCert != "" && c.TLSConfig.ClientKey != "" {
var err error
clientCert, err = tls.LoadX509KeyPair(c.TLSConfig.ClientCert, c.TLSConfig.ClientKey)
if err != nil {
return err
}
foundClientCert = true
} else {
return fmt.Errorf("Both client cert and client key must be provided")
}
}
clientTLSConfig := c.httpClient.Transport.(*http.Transport).TLSClientConfig
rootConfig := &rootcerts.Config{
CAFile: c.TLSConfig.CACert,
CAPath: c.TLSConfig.CAPath,
}
if err := rootcerts.ConfigureTLS(clientTLSConfig, rootConfig); err != nil {
return err
}
clientTLSConfig.InsecureSkipVerify = c.TLSConfig.Insecure
if foundClientCert {
clientTLSConfig.Certificates = []tls.Certificate{clientCert}
}
if c.TLSConfig.TLSServerName != "" {
clientTLSConfig.ServerName = c.TLSConfig.TLSServerName
}
return nil
}
// Client provides a client to the Nomad API
type Client struct {
config Config
}
// NewClient returns a new client
func NewClient(config *Config) (*Client, error) {
// bootstrap the config
defConfig := DefaultConfig()
if config.Address == "" {
config.Address = defConfig.Address
} else if _, err := url.Parse(config.Address); err != nil {
return nil, fmt.Errorf("invalid address '%s': %v", config.Address, err)
}
if config.httpClient == nil {
config.httpClient = defConfig.httpClient
}
// Configure the TLS configurations
if err := config.ConfigureTLS(); err != nil {
return nil, err
}
client := &Client{
config: *config,
}
return client, nil
}
// Address return the address of the Nomad agent
func (c *Client) Address() string {
return c.config.Address
}
// SetRegion sets the region to forward API requests to.
func (c *Client) SetRegion(region string) {
c.config.Region = region
}
// SetNamespace sets the namespace to forward API requests to.
func (c *Client) SetNamespace(namespace string) {
c.config.Namespace = namespace
}
// GetNodeClient returns a new Client that will dial the specified node. If the
// QueryOptions is set, its region will be used.
func (c *Client) GetNodeClient(nodeID string, q *QueryOptions) (*Client, error) {
return c.getNodeClientImpl(nodeID, -1, q, c.Nodes().Info)
}
// GetNodeClientWithTimeout returns a new Client that will dial the specified
// node using the specified timeout. If the QueryOptions is set, its region will
// be used.
func (c *Client) GetNodeClientWithTimeout(
nodeID string, timeout time.Duration, q *QueryOptions) (*Client, error) {
return c.getNodeClientImpl(nodeID, timeout, q, c.Nodes().Info)
}
// nodeLookup is the definition of a function used to lookup a node. This is
// largely used to mock the lookup in tests.
type nodeLookup func(nodeID string, q *QueryOptions) (*Node, *QueryMeta, error)
// getNodeClientImpl is the implementation of creating a API client for
// contacting a node. It takes a function to lookup the node such that it can be
// mocked during tests.
func (c *Client) getNodeClientImpl(nodeID string, timeout time.Duration, q *QueryOptions, lookup nodeLookup) (*Client, error) {
node, _, err := lookup(nodeID, q)
if err != nil {
return nil, err
}
if node.Status == "down" {
return nil, NodeDownErr
}
if node.HTTPAddr == "" {
return nil, fmt.Errorf("http addr of node %q (%s) is not advertised", node.Name, nodeID)
}
var region string
switch {
case q != nil && q.Region != "":
// Prefer the region set in the query parameter
region = q.Region
case c.config.Region != "":
// If the client is configured for a particular region use that
region = c.config.Region
default:
// No region information is given so use the default.
region = "global"
}
// Get an API client for the node
conf := c.config.ClientConfig(region, node.HTTPAddr, node.TLSEnabled)
// Set the timeout
conf.SetTimeout(timeout)
return NewClient(conf)
}
// SetSecretID sets the ACL token secret for API requests.
func (c *Client) SetSecretID(secretID string) {
c.config.SecretID = secretID
}
// request is used to help build up a request
type request struct {
config *Config
method string
url *url.URL
params url.Values
token string
body io.Reader
obj interface{}
}
// setQueryOptions is used to annotate the request with
// additional query options
func (r *request) setQueryOptions(q *QueryOptions) {
if q == nil {
return
}
if q.Region != "" {
r.params.Set("region", q.Region)
}
if q.Namespace != "" {
r.params.Set("namespace", q.Namespace)
}
if q.AuthToken != "" {
r.token = q.AuthToken
}
if q.AllowStale {
r.params.Set("stale", "")
}
if q.WaitIndex != 0 {
r.params.Set("index", strconv.FormatUint(q.WaitIndex, 10))
}
if q.WaitTime != 0 {
r.params.Set("wait", durToMsec(q.WaitTime))
}
if q.Prefix != "" {
r.params.Set("prefix", q.Prefix)
}
for k, v := range q.Params {
r.params.Set(k, v)
}
}
// durToMsec converts a duration to a millisecond specified string
func durToMsec(dur time.Duration) string {
return fmt.Sprintf("%dms", dur/time.Millisecond)
}
// setWriteOptions is used to annotate the request with
// additional write options
func (r *request) setWriteOptions(q *WriteOptions) {
if q == nil {
return
}
if q.Region != "" {
r.params.Set("region", q.Region)
}
if q.Namespace != "" {
r.params.Set("namespace", q.Namespace)
}
if q.AuthToken != "" {
r.token = q.AuthToken
}
}
// toHTTP converts the request to an HTTP request
func (r *request) toHTTP() (*http.Request, error) {
// Encode the query parameters
r.url.RawQuery = r.params.Encode()
// Check if we should encode the body
if r.body == nil && r.obj != nil {
if b, err := encodeBody(r.obj); err != nil {
return nil, err
} else {
r.body = b
}
}
// Create the HTTP request
req, err := http.NewRequest(r.method, r.url.RequestURI(), r.body)
if err != nil {
return nil, err
}
// Optionally configure HTTP basic authentication
if r.url.User != nil {
username := r.url.User.Username()
password, _ := r.url.User.Password()
req.SetBasicAuth(username, password)
} else if r.config.HttpAuth != nil {
req.SetBasicAuth(r.config.HttpAuth.Username, r.config.HttpAuth.Password)
}
req.Header.Add("Accept-Encoding", "gzip")
if r.token != "" {
req.Header.Set("X-Nomad-Token", r.token)
}
req.URL.Host = r.url.Host
req.URL.Scheme = r.url.Scheme
req.Host = r.url.Host
return req, nil
}
// newRequest is used to create a new request
func (c *Client) newRequest(method, path string) (*request, error) {
base, _ := url.Parse(c.config.Address)
u, err := url.Parse(path)
if err != nil {
return nil, err
}
r := &request{
config: &c.config,
method: method,
url: &url.URL{
Scheme: base.Scheme,
User: base.User,
Host: base.Host,
Path: u.Path,
},
params: make(map[string][]string),
}
if c.config.Region != "" {
r.params.Set("region", c.config.Region)
}
if c.config.Namespace != "" {
r.params.Set("namespace", c.config.Namespace)
}
if c.config.WaitTime != 0 {
r.params.Set("wait", durToMsec(r.config.WaitTime))
}
if c.config.SecretID != "" {
r.token = r.config.SecretID
}
// Add in the query parameters, if any
for key, values := range u.Query() {
for _, value := range values {
r.params.Add(key, value)
}
}
return r, nil
}
// multiCloser is to wrap a ReadCloser such that when close is called, multiple
// Closes occur.
type multiCloser struct {
reader io.Reader
inorderClose []io.Closer
}
func (m *multiCloser) Close() error {
for _, c := range m.inorderClose {
if err := c.Close(); err != nil {
return err
}
}
return nil
}
func (m *multiCloser) Read(p []byte) (int, error) {
return m.reader.Read(p)
}
// doRequest runs a request with our client
func (c *Client) doRequest(r *request) (time.Duration, *http.Response, error) {
req, err := r.toHTTP()
if err != nil {
return 0, nil, err
}
start := time.Now()
resp, err := c.config.httpClient.Do(req)
diff := time.Now().Sub(start)
// If the response is compressed, we swap the body's reader.
if resp != nil && resp.Header != nil {
var reader io.ReadCloser
switch resp.Header.Get("Content-Encoding") {
case "gzip":
greader, err := gzip.NewReader(resp.Body)
if err != nil {
return 0, nil, err
}
// The gzip reader doesn't close the wrapped reader so we use
// multiCloser.
reader = &multiCloser{
reader: greader,
inorderClose: []io.Closer{greader, resp.Body},
}
default:
reader = resp.Body
}
resp.Body = reader
}
return diff, resp, err
}
// rawQuery makes a GET request to the specified endpoint but returns just the
// response body.
func (c *Client) rawQuery(endpoint string, q *QueryOptions) (io.ReadCloser, error) {
r, err := c.newRequest("GET", endpoint)
if err != nil {
return nil, err
}
r.setQueryOptions(q)
_, resp, err := requireOK(c.doRequest(r))
if err != nil {
return nil, err
}
return resp.Body, nil
}
// websocket makes a websocket request to the specific endpoint
func (c *Client) websocket(endpoint string, q *QueryOptions) (*websocket.Conn, *http.Response, error) {
transport, ok := c.config.httpClient.Transport.(*http.Transport)
if !ok {
return nil, nil, fmt.Errorf("unsupported transport")
}
dialer := websocket.Dialer{
ReadBufferSize: 4096,
WriteBufferSize: 4096,
HandshakeTimeout: c.config.httpClient.Timeout,
// values to inherit from http client configuration
NetDial: transport.Dial,
NetDialContext: transport.DialContext,
Proxy: transport.Proxy,
TLSClientConfig: transport.TLSClientConfig,
}
// build request object for header and parameters
r, err := c.newRequest("GET", endpoint)
if err != nil {
return nil, nil, err
}
r.setQueryOptions(q)
rhttp, err := r.toHTTP()
if err != nil {
return nil, nil, err
}
// convert scheme
wsScheme := ""
switch rhttp.URL.Scheme {
case "http":
wsScheme = "ws"
case "https":
wsScheme = "wss"
default:
return nil, nil, fmt.Errorf("unsupported scheme: %v", rhttp.URL.Scheme)
}
rhttp.URL.Scheme = wsScheme
conn, resp, err := dialer.Dial(rhttp.URL.String(), rhttp.Header)
// check resp status code, as it's more informative than handshake error we get from ws library
if resp != nil && resp.StatusCode != 101 {
var buf bytes.Buffer
io.Copy(&buf, resp.Body)
resp.Body.Close()
return nil, nil, fmt.Errorf("Unexpected response code: %d (%s)", resp.StatusCode, buf.Bytes())
}
return conn, resp, err
}
// query is used to do a GET request against an endpoint
// and deserialize the response into an interface using
// standard Nomad conventions.
func (c *Client) query(endpoint string, out interface{}, q *QueryOptions) (*QueryMeta, error) {
r, err := c.newRequest("GET", endpoint)
if err != nil {
return nil, err
}
r.setQueryOptions(q)
rtt, resp, err := requireOK(c.doRequest(r))
if err != nil {
return nil, err
}
defer resp.Body.Close()
qm := &QueryMeta{}
parseQueryMeta(resp, qm)
qm.RequestTime = rtt
if err := decodeBody(resp, out); err != nil {
return nil, err
}
return qm, nil
}
// putQuery is used to do a PUT request when doing a read against an endpoint
// and deserialize the response into an interface using standard Nomad
// conventions.
func (c *Client) putQuery(endpoint string, in, out interface{}, q *QueryOptions) (*QueryMeta, error) {
r, err := c.newRequest("PUT", endpoint)
if err != nil {
return nil, err
}
r.setQueryOptions(q)
r.obj = in
rtt, resp, err := requireOK(c.doRequest(r))
if err != nil {
return nil, err
}
defer resp.Body.Close()
qm := &QueryMeta{}
parseQueryMeta(resp, qm)
qm.RequestTime = rtt
if err := decodeBody(resp, out); err != nil {
return nil, err
}
return qm, nil
}
// write is used to do a PUT request against an endpoint
// and serialize/deserialized using the standard Nomad conventions.
func (c *Client) write(endpoint string, in, out interface{}, q *WriteOptions) (*WriteMeta, error) {
r, err := c.newRequest("PUT", endpoint)
if err != nil {
return nil, err
}
r.setWriteOptions(q)
r.obj = in
rtt, resp, err := requireOK(c.doRequest(r))
if err != nil {
return nil, err
}
defer resp.Body.Close()
wm := &WriteMeta{RequestTime: rtt}
parseWriteMeta(resp, wm)
if out != nil {
if err := decodeBody(resp, &out); err != nil {
return nil, err
}
}
return wm, nil
}
// delete is used to do a DELETE request against an endpoint
// and serialize/deserialized using the standard Nomad conventions.
func (c *Client) delete(endpoint string, out interface{}, q *WriteOptions) (*WriteMeta, error) {
r, err := c.newRequest("DELETE", endpoint)
if err != nil {
return nil, err
}
r.setWriteOptions(q)
rtt, resp, err := requireOK(c.doRequest(r))
if err != nil {
return nil, err
}
defer resp.Body.Close()
wm := &WriteMeta{RequestTime: rtt}
parseWriteMeta(resp, wm)
if out != nil {
if err := decodeBody(resp, &out); err != nil {
return nil, err
}
}
return wm, nil
}
// parseQueryMeta is used to help parse query meta-data
func parseQueryMeta(resp *http.Response, q *QueryMeta) error {
header := resp.Header
// Parse the X-Nomad-Index
index, err := strconv.ParseUint(header.Get("X-Nomad-Index"), 10, 64)
if err != nil {
return fmt.Errorf("Failed to parse X-Nomad-Index: %v", err)
}
q.LastIndex = index
// Parse the X-Nomad-LastContact
last, err := strconv.ParseUint(header.Get("X-Nomad-LastContact"), 10, 64)
if err != nil {
return fmt.Errorf("Failed to parse X-Nomad-LastContact: %v", err)
}
q.LastContact = time.Duration(last) * time.Millisecond
// Parse the X-Nomad-KnownLeader
switch header.Get("X-Nomad-KnownLeader") {
case "true":
q.KnownLeader = true
default:
q.KnownLeader = false
}
return nil
}
// parseWriteMeta is used to help parse write meta-data
func parseWriteMeta(resp *http.Response, q *WriteMeta) error {
header := resp.Header
// Parse the X-Nomad-Index
index, err := strconv.ParseUint(header.Get("X-Nomad-Index"), 10, 64)
if err != nil {
return fmt.Errorf("Failed to parse X-Nomad-Index: %v", err)
}
q.LastIndex = index
return nil
}
// decodeBody is used to JSON decode a body
func decodeBody(resp *http.Response, out interface{}) error {
dec := json.NewDecoder(resp.Body)
return dec.Decode(out)
}
// encodeBody is used to encode a request body
func encodeBody(obj interface{}) (io.Reader, error) {
buf := bytes.NewBuffer(nil)
enc := json.NewEncoder(buf)
if err := enc.Encode(obj); err != nil {
return nil, err
}
return buf, nil
}
// requireOK is used to wrap doRequest and check for a 200
func requireOK(d time.Duration, resp *http.Response, e error) (time.Duration, *http.Response, error) {
if e != nil {
if resp != nil {
resp.Body.Close()
}
return d, nil, e
}
if resp.StatusCode != 200 {
var buf bytes.Buffer
io.Copy(&buf, resp.Body)
resp.Body.Close()
return d, nil, fmt.Errorf("Unexpected response code: %d (%s)", resp.StatusCode, buf.Bytes())
}
return d, resp, nil
}