open-consul/api/api.go

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package api
import (
"bytes"
"context"
"crypto/tls"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"log"
"net"
"net/http"
"net/url"
"os"
"strconv"
"strings"
"time"
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"github.com/hashicorp/go-cleanhttp"
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"github.com/hashicorp/go-rootcerts"
)
const (
// HTTPAddrEnvName defines an environment variable name which sets
// the HTTP address if there is no -http-addr specified.
HTTPAddrEnvName = "CONSUL_HTTP_ADDR"
// HTTPTokenEnvName defines an environment variable name which sets
// the HTTP token.
HTTPTokenEnvName = "CONSUL_HTTP_TOKEN"
// HTTPAuthEnvName defines an environment variable name which sets
// the HTTP authentication header.
HTTPAuthEnvName = "CONSUL_HTTP_AUTH"
// HTTPSSLEnvName defines an environment variable name which sets
// whether or not to use HTTPS.
HTTPSSLEnvName = "CONSUL_HTTP_SSL"
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// HTTPCAFile defines an environment variable name which sets the
// CA file to use for talking to Consul over TLS.
HTTPCAFile = "CONSUL_CACERT"
// HTTPCAPath defines an environment variable name which sets the
// path to a directory of CA certs to use for talking to Consul over TLS.
HTTPCAPath = "CONSUL_CAPATH"
// HTTPClientCert defines an environment variable name which sets the
// client cert file to use for talking to Consul over TLS.
HTTPClientCert = "CONSUL_CLIENT_CERT"
// HTTPClientKey defines an environment variable name which sets the
// client key file to use for talking to Consul over TLS.
HTTPClientKey = "CONSUL_CLIENT_KEY"
// HTTPTLSServerName defines an environment variable name which sets the
// server name to use as the SNI host when connecting via TLS
HTTPTLSServerName = "CONSUL_TLS_SERVER_NAME"
// HTTPSSLVerifyEnvName defines an environment variable name which sets
// whether or not to disable certificate checking.
HTTPSSLVerifyEnvName = "CONSUL_HTTP_SSL_VERIFY"
// GRPCAddrEnvName defines an environment variable name which sets the gRPC
// address for consul connect envoy. Note this isn't actually used by the api
// client in this package but is defined here for consistency with all the
// other ENV names we use.
GRPCAddrEnvName = "CONSUL_GRPC_ADDR"
)
// QueryOptions are used to parameterize a query
type QueryOptions struct {
// Providing a datacenter overwrites the DC provided
// by the Config
Datacenter string
// AllowStale allows any Consul server (non-leader) to service
// a read. This allows for lower latency and higher throughput
AllowStale bool
// RequireConsistent forces the read to be fully consistent.
// This is more expensive but prevents ever performing a stale
// read.
RequireConsistent bool
// UseCache requests that the agent cache results locally. See
// https://www.consul.io/api/index.html#agent-caching for more details on the
// semantics.
UseCache bool
// MaxAge limits how old a cached value will be returned if UseCache is true.
// If there is a cached response that is older than the MaxAge, it is treated
// as a cache miss and a new fetch invoked. If the fetch fails, the error is
// returned. Clients that wish to allow for stale results on error can set
// StaleIfError to a longer duration to change this behavior. It is ignored
// if the endpoint supports background refresh caching. See
// https://www.consul.io/api/index.html#agent-caching for more details.
MaxAge time.Duration
// StaleIfError specifies how stale the client will accept a cached response
// if the servers are unavailable to fetch a fresh one. Only makes sense when
// UseCache is true and MaxAge is set to a lower, non-zero value. It is
// ignored if the endpoint supports background refresh caching. See
// https://www.consul.io/api/index.html#agent-caching for more details.
StaleIfError time.Duration
// WaitIndex is used to enable a blocking query. Waits
// until the timeout or the next index is reached
WaitIndex uint64
// WaitHash is used by some endpoints instead of WaitIndex to perform blocking
// on state based on a hash of the response rather than a monotonic index.
// This is required when the state being blocked on is not stored in Raft, for
// example agent-local proxy configuration.
WaitHash string
// WaitTime is used to bound the duration of a wait.
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// Defaults to that of the Config, but can be overridden.
WaitTime time.Duration
// Token is used to provide a per-request ACL token
// which overrides the agent's default token.
Token string
// Near is used to provide a node name that will sort the results
// in ascending order based on the estimated round trip time from
// that node. Setting this to "_agent" will use the agent's node
// for the sort.
Near string
// NodeMeta is used to filter results by nodes with the given
// metadata key/value pairs. Currently, only one key/value pair can
// be provided for filtering.
NodeMeta map[string]string
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// RelayFactor is used in keyring operations to cause responses to be
// relayed back to the sender through N other random nodes. Must be
// a value from 0 to 5 (inclusive).
RelayFactor uint8
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// Connect filters prepared query execution to only include Connect-capable
// services. This currently affects prepared query execution.
Connect bool
// ctx is an optional context pass through to the underlying HTTP
// request layer. Use Context() and WithContext() to manage this.
ctx context.Context
}
func (o *QueryOptions) Context() context.Context {
if o != nil && o.ctx != nil {
return o.ctx
}
return context.Background()
}
func (o *QueryOptions) WithContext(ctx context.Context) *QueryOptions {
o2 := new(QueryOptions)
if o != nil {
*o2 = *o
}
o2.ctx = ctx
return o2
}
// WriteOptions are used to parameterize a write
type WriteOptions struct {
// Providing a datacenter overwrites the DC provided
// by the Config
Datacenter string
// Token is used to provide a per-request ACL token
// which overrides the agent's default token.
Token string
// RelayFactor is used in keyring operations to cause responses to be
// relayed back to the sender through N other random nodes. Must be
// a value from 0 to 5 (inclusive).
RelayFactor uint8
// ctx is an optional context pass through to the underlying HTTP
// request layer. Use Context() and WithContext() to manage this.
ctx context.Context
}
func (o *WriteOptions) Context() context.Context {
if o != nil && o.ctx != nil {
return o.ctx
}
return context.Background()
}
func (o *WriteOptions) WithContext(ctx context.Context) *WriteOptions {
o2 := new(WriteOptions)
if o != nil {
*o2 = *o
}
o2.ctx = ctx
return o2
}
// 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
// LastContentHash. This can be used as a WaitHash to perform a blocking query
// for endpoints that support hash-based blocking. Endpoints that do not
// support it will return an empty hash.
LastContentHash string
// 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
// Is address translation enabled for HTTP responses on this agent
AddressTranslationEnabled bool
// CacheHit is true if the result was served from agent-local cache.
CacheHit bool
// CacheAge is set if request was ?cached and indicates how stale the cached
// response is.
CacheAge time.Duration
}
// WriteMeta is used to return meta data about a write
type WriteMeta struct {
// 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 Consul server
Address string
// Scheme is the URI scheme for the Consul server
Scheme string
// Datacenter to use. If not provided, the default agent datacenter is used.
Datacenter string
// Transport is the Transport to use for the http client.
Transport *http.Transport
// 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
// Token is used to provide a per-request ACL token
// which overrides the agent's default token.
Token string
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TLSConfig TLSConfig
}
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// TLSConfig is used to generate a TLSClientConfig that's useful for talking to
// Consul using TLS.
type TLSConfig struct {
// Address is the optional address of the Consul server. The port, if any
// will be removed from here and this will be set to the ServerName of the
// resulting config.
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Address string
// CAFile is the optional path to the CA certificate used for Consul
// communication, defaults to the system bundle if not specified.
CAFile string
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// CAPath is the optional path to a directory of CA certificates to use for
// Consul communication, defaults to the system bundle if not specified.
CAPath string
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// CertFile is the optional path to the certificate for Consul
// communication. If this is set then you need to also set KeyFile.
CertFile string
// KeyFile is the optional path to the private key for Consul communication.
// If this is set then you need to also set CertFile.
KeyFile string
// InsecureSkipVerify if set to true will disable TLS host verification.
InsecureSkipVerify bool
}
// DefaultConfig returns a default configuration for the client. By default this
// will pool and reuse idle connections to Consul. If you have a long-lived
// client object, this is the desired behavior and should make the most efficient
// use of the connections to Consul. If you don't reuse a client object, which
// is not recommended, then you may notice idle connections building up over
// time. To avoid this, use the DefaultNonPooledConfig() instead.
func DefaultConfig() *Config {
return defaultConfig(cleanhttp.DefaultPooledTransport)
}
// DefaultNonPooledConfig returns a default configuration for the client which
// does not pool connections. This isn't a recommended configuration because it
// will reconnect to Consul on every request, but this is useful to avoid the
// accumulation of idle connections if you make many client objects during the
// lifetime of your application.
func DefaultNonPooledConfig() *Config {
return defaultConfig(cleanhttp.DefaultTransport)
}
// defaultConfig returns the default configuration for the client, using the
// given function to make the transport.
func defaultConfig(transportFn func() *http.Transport) *Config {
config := &Config{
Address: "127.0.0.1:8500",
Scheme: "http",
Transport: transportFn(),
}
if addr := os.Getenv(HTTPAddrEnvName); addr != "" {
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config.Address = addr
}
if token := os.Getenv(HTTPTokenEnvName); token != "" {
config.Token = token
}
if auth := os.Getenv(HTTPAuthEnvName); 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,
}
}
if ssl := os.Getenv(HTTPSSLEnvName); ssl != "" {
enabled, err := strconv.ParseBool(ssl)
if err != nil {
log.Printf("[WARN] client: could not parse %s: %s", HTTPSSLEnvName, err)
}
if enabled {
config.Scheme = "https"
}
}
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if v := os.Getenv(HTTPTLSServerName); v != "" {
config.TLSConfig.Address = v
}
if v := os.Getenv(HTTPCAFile); v != "" {
config.TLSConfig.CAFile = v
}
if v := os.Getenv(HTTPCAPath); v != "" {
config.TLSConfig.CAPath = v
}
if v := os.Getenv(HTTPClientCert); v != "" {
config.TLSConfig.CertFile = v
}
if v := os.Getenv(HTTPClientKey); v != "" {
config.TLSConfig.KeyFile = v
}
if v := os.Getenv(HTTPSSLVerifyEnvName); v != "" {
doVerify, err := strconv.ParseBool(v)
if err != nil {
log.Printf("[WARN] client: could not parse %s: %s", HTTPSSLVerifyEnvName, err)
}
if !doVerify {
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config.TLSConfig.InsecureSkipVerify = true
}
}
return config
}
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// TLSConfig is used to generate a TLSClientConfig that's useful for talking to
// Consul using TLS.
func SetupTLSConfig(tlsConfig *TLSConfig) (*tls.Config, error) {
tlsClientConfig := &tls.Config{
InsecureSkipVerify: tlsConfig.InsecureSkipVerify,
}
if tlsConfig.Address != "" {
server := tlsConfig.Address
hasPort := strings.LastIndex(server, ":") > strings.LastIndex(server, "]")
if hasPort {
var err error
server, _, err = net.SplitHostPort(server)
if err != nil {
return nil, err
}
}
tlsClientConfig.ServerName = server
}
if tlsConfig.CertFile != "" && tlsConfig.KeyFile != "" {
tlsCert, err := tls.LoadX509KeyPair(tlsConfig.CertFile, tlsConfig.KeyFile)
if err != nil {
return nil, err
}
tlsClientConfig.Certificates = []tls.Certificate{tlsCert}
}
if tlsConfig.CAFile != "" || tlsConfig.CAPath != "" {
rootConfig := &rootcerts.Config{
CAFile: tlsConfig.CAFile,
CAPath: tlsConfig.CAPath,
}
if err := rootcerts.ConfigureTLS(tlsClientConfig, rootConfig); err != nil {
return nil, err
}
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}
return tlsClientConfig, nil
}
func (c *Config) GenerateEnv() []string {
env := make([]string, 0, 10)
env = append(env,
fmt.Sprintf("%s=%s", HTTPAddrEnvName, c.Address),
fmt.Sprintf("%s=%s", HTTPTokenEnvName, c.Token),
fmt.Sprintf("%s=%t", HTTPSSLEnvName, c.Scheme == "https"),
fmt.Sprintf("%s=%s", HTTPCAFile, c.TLSConfig.CAFile),
fmt.Sprintf("%s=%s", HTTPCAPath, c.TLSConfig.CAPath),
fmt.Sprintf("%s=%s", HTTPClientCert, c.TLSConfig.CertFile),
fmt.Sprintf("%s=%s", HTTPClientKey, c.TLSConfig.KeyFile),
fmt.Sprintf("%s=%s", HTTPTLSServerName, c.TLSConfig.Address),
fmt.Sprintf("%s=%t", HTTPSSLVerifyEnvName, !c.TLSConfig.InsecureSkipVerify))
if c.HttpAuth != nil {
env = append(env, fmt.Sprintf("%s=%s:%s", HTTPAuthEnvName, c.HttpAuth.Username, c.HttpAuth.Password))
} else {
env = append(env, fmt.Sprintf("%s=", HTTPAuthEnvName))
}
return env
}
// Client provides a client to the Consul API
type Client struct {
config Config
}
// NewClient returns a new client
func NewClient(config *Config) (*Client, error) {
// bootstrap the config
defConfig := DefaultConfig()
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if len(config.Address) == 0 {
config.Address = defConfig.Address
}
if len(config.Scheme) == 0 {
config.Scheme = defConfig.Scheme
}
if config.Transport == nil {
config.Transport = defConfig.Transport
}
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if config.TLSConfig.Address == "" {
config.TLSConfig.Address = defConfig.TLSConfig.Address
}
if config.TLSConfig.CAFile == "" {
config.TLSConfig.CAFile = defConfig.TLSConfig.CAFile
}
if config.TLSConfig.CAPath == "" {
config.TLSConfig.CAPath = defConfig.TLSConfig.CAPath
}
if config.TLSConfig.CertFile == "" {
config.TLSConfig.CertFile = defConfig.TLSConfig.CertFile
}
if config.TLSConfig.KeyFile == "" {
config.TLSConfig.KeyFile = defConfig.TLSConfig.KeyFile
}
if !config.TLSConfig.InsecureSkipVerify {
config.TLSConfig.InsecureSkipVerify = defConfig.TLSConfig.InsecureSkipVerify
}
if config.HttpClient == nil {
var err error
config.HttpClient, err = NewHttpClient(config.Transport, config.TLSConfig)
if err != nil {
return nil, err
}
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}
parts := strings.SplitN(config.Address, "://", 2)
if len(parts) == 2 {
switch parts[0] {
case "http":
New config parser, HCL support, multiple bind addrs (#3480) * new config parser for agent This patch implements a new config parser for the consul agent which makes the following changes to the previous implementation: * add HCL support * all configuration fragments in tests and for default config are expressed as HCL fragments * HCL fragments can be provided on the command line so that they can eventually replace the command line flags. * HCL/JSON fragments are parsed into a temporary Config structure which can be merged using reflection (all values are pointers). The existing merge logic of overwrite for values and append for slices has been preserved. * A single builder process generates a typed runtime configuration for the agent. The new implementation is more strict and fails in the builder process if no valid runtime configuration can be generated. Therefore, additional validations in other parts of the code should be removed. The builder also pre-computes all required network addresses so that no address/port magic should be required where the configuration is used and should therefore be removed. * Upgrade github.com/hashicorp/hcl to support int64 * improve error messages * fix directory permission test * Fix rtt test * Fix ForceLeave test * Skip performance test for now until we know what to do * Update github.com/hashicorp/memberlist to update log prefix * Make memberlist use the default logger * improve config error handling * do not fail on non-existing data-dir * experiment with non-uniform timeouts to get a handle on stalled leader elections * Run tests for packages separately to eliminate the spurious port conflicts * refactor private address detection and unify approach for ipv4 and ipv6. Fixes #2825 * do not allow unix sockets for DNS * improve bind and advertise addr error handling * go through builder using test coverage * minimal update to the docs * more coverage tests fixed * more tests * fix makefile * cleanup * fix port conflicts with external port server 'porter' * stop test server on error * do not run api test that change global ENV concurrently with the other tests * Run remaining api tests concurrently * no need for retry with the port number service * monkey patch race condition in go-sockaddr until we understand why that fails * monkey patch hcl decoder race condidtion until we understand why that fails * monkey patch spurious errors in strings.EqualFold from here * add test for hcl decoder race condition. Run with go test -parallel 128 * Increase timeout again * cleanup * don't log port allocations by default * use base command arg parsing to format help output properly * handle -dc deprecation case in Build * switch autopilot.max_trailing_logs to int * remove duplicate test case * remove unused methods * remove comments about flag/config value inconsistencies * switch got and want around since the error message was misleading. * Removes a stray debug log. * Removes a stray newline in imports. * Fixes TestACL_Version8. * Runs go fmt. * Adds a default case for unknown address types. * Reoders and reformats some imports. * Adds some comments and fixes typos. * Reorders imports. * add unix socket support for dns later * drop all deprecated flags and arguments * fix wrong field name * remove stray node-id file * drop unnecessary patch section in test * drop duplicate test * add test for LeaveOnTerm and SkipLeaveOnInt in client mode * drop "bla" and add clarifying comment for the test * split up tests to support enterprise/non-enterprise tests * drop raft multiplier and derive values during build phase * sanitize runtime config reflectively and add test * detect invalid config fields * fix tests with invalid config fields * use different values for wan sanitiziation test * drop recursor in favor of recursors * allow dns_config.udp_answer_limit to be zero * make sure tests run on machines with multiple ips * Fix failing tests in a few more places by providing a bind address in the test * Gets rid of skipped TestAgent_CheckPerformanceSettings and adds case for builder. * Add porter to server_test.go to make tests there less flaky * go fmt
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config.Scheme = "http"
case "https":
config.Scheme = "https"
case "unix":
trans := cleanhttp.DefaultTransport()
trans.DialContext = func(_ context.Context, _, _ string) (net.Conn, error) {
return net.Dial("unix", parts[1])
}
config.HttpClient = &http.Client{
Transport: trans,
}
default:
return nil, fmt.Errorf("Unknown protocol scheme: %s", parts[0])
}
config.Address = parts[1]
}
if config.Token == "" {
config.Token = defConfig.Token
}
New config parser, HCL support, multiple bind addrs (#3480) * new config parser for agent This patch implements a new config parser for the consul agent which makes the following changes to the previous implementation: * add HCL support * all configuration fragments in tests and for default config are expressed as HCL fragments * HCL fragments can be provided on the command line so that they can eventually replace the command line flags. * HCL/JSON fragments are parsed into a temporary Config structure which can be merged using reflection (all values are pointers). The existing merge logic of overwrite for values and append for slices has been preserved. * A single builder process generates a typed runtime configuration for the agent. The new implementation is more strict and fails in the builder process if no valid runtime configuration can be generated. Therefore, additional validations in other parts of the code should be removed. The builder also pre-computes all required network addresses so that no address/port magic should be required where the configuration is used and should therefore be removed. * Upgrade github.com/hashicorp/hcl to support int64 * improve error messages * fix directory permission test * Fix rtt test * Fix ForceLeave test * Skip performance test for now until we know what to do * Update github.com/hashicorp/memberlist to update log prefix * Make memberlist use the default logger * improve config error handling * do not fail on non-existing data-dir * experiment with non-uniform timeouts to get a handle on stalled leader elections * Run tests for packages separately to eliminate the spurious port conflicts * refactor private address detection and unify approach for ipv4 and ipv6. Fixes #2825 * do not allow unix sockets for DNS * improve bind and advertise addr error handling * go through builder using test coverage * minimal update to the docs * more coverage tests fixed * more tests * fix makefile * cleanup * fix port conflicts with external port server 'porter' * stop test server on error * do not run api test that change global ENV concurrently with the other tests * Run remaining api tests concurrently * no need for retry with the port number service * monkey patch race condition in go-sockaddr until we understand why that fails * monkey patch hcl decoder race condidtion until we understand why that fails * monkey patch spurious errors in strings.EqualFold from here * add test for hcl decoder race condition. Run with go test -parallel 128 * Increase timeout again * cleanup * don't log port allocations by default * use base command arg parsing to format help output properly * handle -dc deprecation case in Build * switch autopilot.max_trailing_logs to int * remove duplicate test case * remove unused methods * remove comments about flag/config value inconsistencies * switch got and want around since the error message was misleading. * Removes a stray debug log. * Removes a stray newline in imports. * Fixes TestACL_Version8. * Runs go fmt. * Adds a default case for unknown address types. * Reoders and reformats some imports. * Adds some comments and fixes typos. * Reorders imports. * add unix socket support for dns later * drop all deprecated flags and arguments * fix wrong field name * remove stray node-id file * drop unnecessary patch section in test * drop duplicate test * add test for LeaveOnTerm and SkipLeaveOnInt in client mode * drop "bla" and add clarifying comment for the test * split up tests to support enterprise/non-enterprise tests * drop raft multiplier and derive values during build phase * sanitize runtime config reflectively and add test * detect invalid config fields * fix tests with invalid config fields * use different values for wan sanitiziation test * drop recursor in favor of recursors * allow dns_config.udp_answer_limit to be zero * make sure tests run on machines with multiple ips * Fix failing tests in a few more places by providing a bind address in the test * Gets rid of skipped TestAgent_CheckPerformanceSettings and adds case for builder. * Add porter to server_test.go to make tests there less flaky * go fmt
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return &Client{config: *config}, nil
}
// NewHttpClient returns an http client configured with the given Transport and TLS
// config.
func NewHttpClient(transport *http.Transport, tlsConf TLSConfig) (*http.Client, error) {
client := &http.Client{
Transport: transport,
}
// TODO (slackpad) - Once we get some run time on the HTTP/2 support we
// should turn it on by default if TLS is enabled. We would basically
// just need to call http2.ConfigureTransport(transport) here. We also
// don't want to introduce another external dependency on
// golang.org/x/net/http2 at this time. For a complete recipe for how
// to enable HTTP/2 support on a transport suitable for the API client
// library see agent/http_test.go:TestHTTPServer_H2.
if transport.TLSClientConfig == nil {
tlsClientConfig, err := SetupTLSConfig(&tlsConf)
if err != nil {
return nil, err
}
transport.TLSClientConfig = tlsClientConfig
}
return client, nil
}
// request is used to help build up a request
type request struct {
config *Config
method string
url *url.URL
params url.Values
body io.Reader
header http.Header
obj interface{}
ctx context.Context
}
// setQueryOptions is used to annotate the request with
// additional query options
func (r *request) setQueryOptions(q *QueryOptions) {
if q == nil {
return
}
if q.Datacenter != "" {
r.params.Set("dc", q.Datacenter)
}
if q.AllowStale {
r.params.Set("stale", "")
}
if q.RequireConsistent {
r.params.Set("consistent", "")
}
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.WaitHash != "" {
r.params.Set("hash", q.WaitHash)
}
if q.Token != "" {
r.header.Set("X-Consul-Token", q.Token)
}
if q.Near != "" {
r.params.Set("near", q.Near)
}
if len(q.NodeMeta) > 0 {
for key, value := range q.NodeMeta {
r.params.Add("node-meta", key+":"+value)
}
}
if q.RelayFactor != 0 {
r.params.Set("relay-factor", strconv.Itoa(int(q.RelayFactor)))
}
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if q.Connect {
r.params.Set("connect", "true")
}
if q.UseCache && !q.RequireConsistent {
r.params.Set("cached", "")
cc := []string{}
if q.MaxAge > 0 {
cc = append(cc, fmt.Sprintf("max-age=%.0f", q.MaxAge.Seconds()))
}
if q.StaleIfError > 0 {
cc = append(cc, fmt.Sprintf("stale-if-error=%.0f", q.StaleIfError.Seconds()))
}
if len(cc) > 0 {
r.header.Set("Cache-Control", strings.Join(cc, ", "))
}
}
r.ctx = q.ctx
}
// durToMsec converts a duration to a millisecond specified string. If the
// user selected a positive value that rounds to 0 ms, then we will use 1 ms
// so they get a short delay, otherwise Consul will translate the 0 ms into
// a huge default delay.
func durToMsec(dur time.Duration) string {
ms := dur / time.Millisecond
if dur > 0 && ms == 0 {
ms = 1
}
return fmt.Sprintf("%dms", ms)
}
// serverError is a string we look for to detect 500 errors.
const serverError = "Unexpected response code: 500"
// IsRetryableError returns true for 500 errors from the Consul servers, and
// network connection errors. These are usually retryable at a later time.
// This applies to reads but NOT to writes. This may return true for errors
// on writes that may have still gone through, so do not use this to retry
// any write operations.
func IsRetryableError(err error) bool {
if err == nil {
return false
}
if _, ok := err.(net.Error); ok {
return true
}
// TODO (slackpad) - Make a real error type here instead of using
// a string check.
return strings.Contains(err.Error(), serverError)
}
// setWriteOptions is used to annotate the request with
// additional write options
func (r *request) setWriteOptions(q *WriteOptions) {
if q == nil {
return
}
if q.Datacenter != "" {
r.params.Set("dc", q.Datacenter)
}
if q.Token != "" {
r.header.Set("X-Consul-Token", q.Token)
}
if q.RelayFactor != 0 {
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r.params.Set("relay-factor", strconv.Itoa(int(q.RelayFactor)))
}
r.ctx = q.ctx
}
// 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 {
b, err := encodeBody(r.obj)
if err != nil {
return nil, err
}
r.body = b
}
// Create the HTTP request
req, err := http.NewRequest(r.method, r.url.RequestURI(), r.body)
if err != nil {
return nil, err
}
req.URL.Host = r.url.Host
req.URL.Scheme = r.url.Scheme
req.Host = r.url.Host
req.Header = r.header
// Setup auth
if r.config.HttpAuth != nil {
req.SetBasicAuth(r.config.HttpAuth.Username, r.config.HttpAuth.Password)
}
if r.ctx != nil {
return req.WithContext(r.ctx), nil
}
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return req, nil
}
// newRequest is used to create a new request
func (c *Client) newRequest(method, path string) *request {
r := &request{
config: &c.config,
method: method,
url: &url.URL{
Scheme: c.config.Scheme,
Host: c.config.Address,
Path: path,
},
params: make(map[string][]string),
header: make(http.Header),
}
if c.config.Datacenter != "" {
r.params.Set("dc", c.config.Datacenter)
}
if c.config.WaitTime != 0 {
r.params.Set("wait", durToMsec(r.config.WaitTime))
}
if c.config.Token != "" {
r.header.Set("X-Consul-Token", r.config.Token)
}
return r
}
// 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.Since(start)
return diff, resp, err
}
// Query is used to do a GET request against an endpoint
// and deserialize the response into an interface using
// standard Consul conventions.
func (c *Client) query(endpoint string, out interface{}, q *QueryOptions) (*QueryMeta, error) {
r := c.newRequest("GET", endpoint)
r.setQueryOptions(q)
rtt, resp, err := 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 Consul conventions.
func (c *Client) write(endpoint string, in, out interface{}, q *WriteOptions) (*WriteMeta, error) {
r := c.newRequest("PUT", endpoint)
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}
if out != nil {
if err := decodeBody(resp, &out); err != nil {
return nil, err
}
} else if _, err := ioutil.ReadAll(resp.Body); 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-Consul-Index (if it's set - hash based blocking queries don't
// set this)
if indexStr := header.Get("X-Consul-Index"); indexStr != "" {
index, err := strconv.ParseUint(indexStr, 10, 64)
if err != nil {
return fmt.Errorf("Failed to parse X-Consul-Index: %v", err)
}
q.LastIndex = index
}
q.LastContentHash = header.Get("X-Consul-ContentHash")
// Parse the X-Consul-LastContact
last, err := strconv.ParseUint(header.Get("X-Consul-LastContact"), 10, 64)
if err != nil {
return fmt.Errorf("Failed to parse X-Consul-LastContact: %v", err)
}
q.LastContact = time.Duration(last) * time.Millisecond
// Parse the X-Consul-KnownLeader
switch header.Get("X-Consul-KnownLeader") {
case "true":
q.KnownLeader = true
default:
q.KnownLeader = false
}
// Parse X-Consul-Translate-Addresses
switch header.Get("X-Consul-Translate-Addresses") {
case "true":
q.AddressTranslationEnabled = true
default:
q.AddressTranslationEnabled = false
}
// Parse Cache info
if cacheStr := header.Get("X-Cache"); cacheStr != "" {
q.CacheHit = strings.EqualFold(cacheStr, "HIT")
}
if ageStr := header.Get("Age"); ageStr != "" {
age, err := strconv.ParseUint(ageStr, 10, 64)
if err != nil {
return fmt.Errorf("Failed to parse Age Header: %v", err)
}
q.CacheAge = time.Duration(age) * time.Second
}
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
}