Commit ca5dcc56 authored by ale's avatar ale

Update go-common/clientutil

parent d5fd9a28
Pipeline #3657 passed with stages
in 5 minutes and 56 seconds
ai3/go-common
===
Common code for ai3 services and tools.
A quick overview of the contents:
* [client](clientutil/) and [server](serverutil/) HTTP-based
"RPC" implementation, just JSON POST requests but with retries,
backoff, timeouts, tracing, etc.
* [server implementation of a generic line-based protocol over a UNIX
socket](unix/).
* a [LDAP connection pool](ldap/).
* utilities to [serialize composite data types](ldap/compositetypes/)
used in our LDAP database.
* a [password hashing library](pwhash/) that uses fancy advanced
crypto by default but is also backwards compatible with old
libc crypto.
* utilities to [manage encryption keys](userenckey/), themselves
encrypted with a password and a KDF.
......@@ -98,43 +98,69 @@ func newBalancedBackend(config *BackendConfig, resolver resolver) (*balancedBack
// with a JSON-encoded request body. It will attempt to decode the
// response body as JSON.
func (b *balancedBackend) Call(ctx context.Context, shard, path string, req, resp interface{}) error {
// Serialize the request body.
data, err := json.Marshal(req)
if err != nil {
return err
}
var tg targetGenerator = b.backendTracker
if b.sharded {
if shard == "" {
return fmt.Errorf("call without shard to sharded service %s", b.baseURI.String())
}
tg = newShardedGenerator(shard, b.baseURI.Host, b.resolver)
// Create the target sequence for this call. If there are multiple
// targets, reduce the timeout on each individual call accordingly to
// accomodate eventual failover.
seq, err := b.makeSequence(shard)
if err != nil {
return err
}
innerTimeout := 1 * time.Hour
if deadline, ok := ctx.Deadline(); ok {
innerTimeout = time.Until(deadline) / time.Duration(seq.Len())
}
seq := newSequence(tg)
b.log.Printf("%016x: initialized", seq.ID())
var httpResp *http.Response
err = backoff.Retry(func() error {
// Call the backends in the sequence until one succeeds, with an
// exponential backoff policy controlled by the outer Context.
return backoff.Retry(func() error {
req, rerr := b.newJSONRequest(path, shard, data)
if rerr != nil {
return rerr
}
httpResp, rerr = b.do(ctx, seq, req)
return rerr
innerCtx, cancel := context.WithTimeout(ctx, innerTimeout)
defer cancel()
// When do() returns successfully, we already know that the
// response had an HTTP status of 200.
httpResp, rerr := b.do(innerCtx, seq, req)
if rerr != nil {
return rerr
}
defer httpResp.Body.Close() // nolint
// Decode the response, unless the 'resp' output is nil.
if httpResp.Header.Get("Content-Type") != "application/json" {
return errors.New("not a JSON response")
}
if resp == nil {
return nil
}
return json.NewDecoder(httpResp.Body).Decode(resp)
}, backoff.WithContext(newExponentialBackOff(), ctx))
if err != nil {
return err
}
defer httpResp.Body.Close() // nolint
}
if httpResp.Header.Get("Content-Type") != "application/json" {
return errors.New("not a JSON response")
// Initialize a new target sequence.
func (b *balancedBackend) makeSequence(shard string) (*sequence, error) {
var tg targetGenerator = b.backendTracker
if b.sharded {
if shard == "" {
return nil, fmt.Errorf("call without shard to sharded service %s", b.baseURI.String())
}
tg = newShardedGenerator(shard, b.baseURI.Host, b.resolver)
}
if resp == nil {
return nil
seq := newSequence(tg)
if seq.Len() == 0 {
return nil, errNoTargets
}
return json.NewDecoder(httpResp.Body).Decode(resp)
b.log.Printf("%016x: initialized", seq.ID())
return seq, nil
}
// Return the URI to be used for the request. This is used both in the
......@@ -213,6 +239,8 @@ func newSequence(tg targetGenerator) *sequence {
func (s *sequence) ID() uint64 { return s.id }
func (s *sequence) Len() int { return len(s.targets) }
func (s *sequence) reloadTargets() {
targets := s.tg.getTargets()
if len(targets) > 0 {
......
......@@ -8,6 +8,7 @@ import (
"net/http"
"os"
"path/filepath"
"strconv"
"sync"
openzipkin "github.com/openzipkin/zipkin-go"
......@@ -31,6 +32,7 @@ const globalTracingConfigPath = "/etc/tracing/client.conf"
type tracingConfig struct {
ReportURL string `json:"report_url"`
Sample string `json:"sample"`
}
// Read the global tracing configuration file. Its location is
......@@ -91,6 +93,9 @@ func init() {
}
func initTracing(endpointAddr string) {
if !Enabled {
return
}
initOnce.Do(func() {
localEndpoint, err := openzipkin.NewEndpoint(getServiceName(), endpointAddr)
if err != nil {
......@@ -100,9 +105,23 @@ func initTracing(endpointAddr string) {
reporter := zipkinHTTP.NewReporter(config.ReportURL)
ze := zipkin.NewExporter(reporter, localEndpoint)
trace.RegisterExporter(ze)
trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
var tc trace.Config
switch config.Sample {
case "", "always":
tc.DefaultSampler = trace.AlwaysSample()
case "never":
tc.DefaultSampler = trace.NeverSample()
default:
frac, err := strconv.ParseFloat(config.Sample, 64)
if err != nil {
log.Printf("warning: error in tracing configuration: sample: %v, tracing disabled", err)
return
}
tc.DefaultSampler = trace.ProbabilitySampler(frac)
}
trace.ApplyConfig(tc)
log.Printf("tracing enabled (report_url %s)", config.ReportURL)
......@@ -110,6 +129,11 @@ func initTracing(endpointAddr string) {
})
}
// Init tracing support, if not using WrapHandler.
func Init() {
initTracing("")
}
// WrapTransport optionally wraps a http.RoundTripper with OpenCensus
// tracing functionality, if it is globally enabled.
func WrapTransport(t http.RoundTripper) http.RoundTripper {
......@@ -120,7 +144,7 @@ func WrapTransport(t http.RoundTripper) http.RoundTripper {
}
// WrapHandler wraps a http.Handler with OpenCensus tracing
// functionality, if globally enabled.
// functionality, if globally enabled. Automatically calls Init().
func WrapHandler(h http.Handler, endpointAddr string) http.Handler {
if Enabled {
initTracing(endpointAddr)
......
......@@ -3,28 +3,28 @@
"ignore": "test",
"package": [
{
"checksumSHA1": "pLvPnUablirQucyALgrso9hLG4E=",
"checksumSHA1": "oUOxU+Tw1/jOzWVP05HuGvVSC/A=",
"path": "git.autistici.org/ai3/go-common",
"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
"revisionTime": "2018-11-18T16:11:30Z"
"revision": "54f0ac4c46184ae44486a31ca2705076abcc5321",
"revisionTime": "2019-06-30T08:30:15Z"
},
{
"checksumSHA1": "1ChQcW9Biu/AgiKjsbJFg/+WhjQ=",
"checksumSHA1": "kJwm6y9JXhybelO2zUl7UbzIdP0=",
"path": "git.autistici.org/ai3/go-common/clientutil",
"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
"revisionTime": "2018-11-18T16:11:30Z"
"revision": "54f0ac4c46184ae44486a31ca2705076abcc5321",
"revisionTime": "2019-06-30T08:30:15Z"
},
{
"checksumSHA1": "TKGUNmKxj7KH3qhwiCh/6quUnwc=",
"path": "git.autistici.org/ai3/go-common/serverutil",
"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
"revisionTime": "2018-11-18T16:11:30Z"
"revision": "54f0ac4c46184ae44486a31ca2705076abcc5321",
"revisionTime": "2019-06-30T08:30:15Z"
},
{
"checksumSHA1": "WvuSF0pz3rk7bu+5g9lqTqq97Ow=",
"checksumSHA1": "y5pRYZ/NhfEOCFslPEuUZTYXcro=",
"path": "git.autistici.org/ai3/go-common/tracing",
"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
"revisionTime": "2018-11-18T16:11:30Z"
"revision": "54f0ac4c46184ae44486a31ca2705076abcc5321",
"revisionTime": "2019-06-30T08:30:15Z"
},
{
"checksumSHA1": "yRc5umgrV1NRzXHqjkHSUAXIvpg=",
......
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