OpenCensus tracing

Makefile

@@ -26,7 +26,7 @@ vet:
 golint:
 	golint -set_exit_status ./...
 gocyclo:
-	gocyclo -over 12 $(GO_FILES_NO_TEST)
+	gocyclo -over 13 $(GO_FILES_NO_TEST)
 errcheck:
 	errcheck -ignoretests ./...
 nakedret:

go.mod

@@ -7,6 +7,8 @@ require (
 	github.com/kisielk/errcheck v1.1.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/stretchr/testify v1.2.2
+	go.opencensus.io v0.18.0
 	golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3 // indirect
-	golang.org/x/tools v0.0.0-20181101071927-45ff765b4815 // indirect
+	golang.org/x/net v0.0.0-20181029044818-c44066c5c816 // indirect
+	golang.org/x/tools v0.0.0-20181102050050-92b943e6bff7 // indirect
 )

go.sum

@@ -1,19 +1,46 @@
+git.apache.org/thrift.git v0.0.0-20180902110319-2566ecd5d999/go.mod h1:fPE2ZNJGynbRyZ4dJvy6G277gSllfV2HJqblrnkyeyg=
 github.com/alexkohler/nakedret v0.0.0-20171106223215-c0e305a4f690 h1:+tfdYWf4oDrj9c0/77f5oDBxZT2EPjS1AJf+PApGNCk=
 github.com/alexkohler/nakedret v0.0.0-20171106223215-c0e305a4f690/go.mod h1:tfDQbtPt67HhBK/6P0yNktIX7peCxfOp0jO9007DrLE=
+github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fzipp/gocyclo v0.0.0-20150627053110-6acd4345c835 h1:roDmqJ4Qes7hrDOsWsMCce0vQHz3xiMPjJ9m4c2eeNs=
 github.com/fzipp/gocyclo v0.0.0-20150627053110-6acd4345c835/go.mod h1:BjL/N0+C+j9uNX+1xcNuM9vdSIcXCZrQZUYbXOFbgN8=
+github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
+github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
+github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+github.com/grpc-ecosystem/grpc-gateway v1.5.0/go.mod h1:RSKVYQBd5MCa4OVpNdGskqpgL2+G+NZTnrVHpWWfpdw=
 github.com/kisielk/errcheck v1.1.0 h1:ZqfnKyx9KGpRcW04j5nnPDgRgoXUeLh2YFBeFzphcA0=
 github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
 github.com/kisielk/gotool v1.0.0 h1:AV2c/EiW3KqPNT9ZKl07ehoAGi4C5/01Cfbblndcapg=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/openzipkin/zipkin-go v0.1.1/go.mod h1:NtoC/o8u3JlF1lSlyPNswIbeQH9bJTmOf0Erfk+hxe8=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v0.8.0/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
+github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
+github.com/prometheus/common v0.0.0-20180801064454-c7de2306084e/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
+github.com/prometheus/procfs v0.0.0-20180725123919-05ee40e3a273/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+go.opencensus.io v0.18.0 h1:Mk5rgZcggtbvtAun5aJzAtjKKN/t0R3jJPlWILlv938=
+go.opencensus.io v0.18.0/go.mod h1:vKdFvxhtzZ9onBp9VKHK8z/sRpBMnKAsufL7wlDrCOA=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3 h1:x/bBzNauLQAlE3fLku/xy92Y8QwKX5HZymrMz2IiKFc=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
+golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20181029044818-c44066c5c816 h1:mVFkLpejdFLXVUv9E42f3XJVfMdqd0IVLVIVLjZWn5o=
+golang.org/x/net v0.0.0-20181029044818-c44066c5c816/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20181101071927-45ff765b4815 h1:MFLfgxncXyUrOtGJGmWoQH0yNFWSHGuJjDWqYe1h9Ug=
-golang.org/x/tools v0.0.0-20181101071927-45ff765b4815/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20181102050050-92b943e6bff7 h1:BdbtPv/+DFTRA5+9560n/FamYyleF+XonScH/3H1+Tk=
+golang.org/x/tools v0.0.0-20181102050050-92b943e6bff7/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+google.golang.org/api v0.0.0-20180910000450-7ca32eb868bf/go.mod h1:4mhQ8q/RsB7i+udVvVy5NUi08OU8ZlA0gRVgrF7VFY0=
+google.golang.org/genproto v0.0.0-20180831171423-11092d34479b/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
+google.golang.org/grpc v1.14.0/go.mod h1:yo6s7OP7yaDglbqo1J04qKzAhqBH6lvTonzMVmEdcZw=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

search.go

@@ -9,6 +9,8 @@ import (
 	"net/url"
 	"strconv"
 	"time"
+
+	"go.opencensus.io/trace"
 )
 
 var (
@@ -27,28 +29,46 @@ var (
 // - context has a deadline/timeout set and
 // - seconds to wait is not after context's deadline/timeout, making this fail early
 func (cms *Contentful) GetMany(ctx context.Context, parameters SearchParameters, data interface{}) error {
+	ctx, span := trace.StartSpan(ctx, "github.com/janivihervas/contentful-go.GetMany")
+	defer span.End()
+
 	response, err := cms.search(ctx, parameters)
 	if err != nil {
+		addSpanError(span, trace.StatusCodeUnknown, err)
 		return err
 	}
 
 	if response.Total == 0 || len(response.Items) == 0 {
+		addSpanError(span, trace.StatusCodeNotFound, ErrNoEntries)
 		return ErrNoEntries
 	}
 
+	_, spanParse := trace.StartSpan(ctx, "github.com/janivihervas/contentful-go.parse")
+	defer spanParse.End()
 	appendIncludes(&response)
 
 	flattenedItems, err := flattenItems(response.Includes, response.Items)
 	if err != nil {
+		addSpanError(spanParse, trace.StatusCodeUnknown, err)
+		addSpanError(span, trace.StatusCodeUnknown, err)
 		return err
 	}
 
 	bytes, err := json.Marshal(flattenedItems)
 	if err != nil {
+		addSpanError(spanParse, trace.StatusCodeInternal, err)
+		addSpanError(span, trace.StatusCodeInternal, err)
 		return err
 	}
 
-	return json.Unmarshal(bytes, data)
+	err = json.Unmarshal(bytes, data)
+	if err != nil {
+		addSpanError(spanParse, trace.StatusCodeInternal, err)
+		addSpanError(span, trace.StatusCodeInternal, err)
+		return err
+	}
+
+	return nil
 }
 
 // GetOne entry from Contentful. The flattened json output will be marshaled into data parameter.
@@ -58,74 +78,134 @@ func (cms *Contentful) GetMany(ctx context.Context, parameters SearchParameters,
 // - context has a deadline/timeout set and
 // - seconds to wait is not after context's deadline/timeout, making this fail early
 func (cms *Contentful) GetOne(ctx context.Context, parameters SearchParameters, data interface{}) error {
+	ctx, span := trace.StartSpan(ctx, "github.com/janivihervas/contentful-go.GetOne")
+	defer span.End()
+
 	response, err := cms.search(ctx, parameters)
 	if err != nil {
+		addSpanError(span, trace.StatusCodeUnknown, err)
 		return err
 	}
 
 	if response.Total == 0 || len(response.Items) == 0 {
+		addSpanError(span, trace.StatusCodeNotFound, ErrNoEntries)
 		return ErrNoEntries
 	}
 
 	if response.Total != 1 || len(response.Items) != 1 {
+		addSpanError(span, trace.StatusCodeOutOfRange, ErrMoreThanOneEntry)
 		return ErrMoreThanOneEntry
 	}
 
+	_, spanParse := trace.StartSpan(ctx, "github.com/janivihervas/contentful-go.parse")
+	defer spanParse.End()
 	appendIncludes(&response)
 
 	flattenedItem, err := flattenItem(response.Includes, response.Items[0])
 	if err != nil {
+		addSpanError(spanParse, trace.StatusCodeUnknown, err)
+		addSpanError(span, trace.StatusCodeUnknown, err)
 		return err
 	}
 
 	bytes, err := json.Marshal(flattenedItem)
 	if err != nil {
+		addSpanError(spanParse, trace.StatusCodeInternal, err)
+		addSpanError(span, trace.StatusCodeInternal, err)
 		return err
 	}
 
-	return json.Unmarshal(bytes, data)
+	err = json.Unmarshal(bytes, data)
+	if err != nil {
+		addSpanError(spanParse, trace.StatusCodeInternal, err)
+		addSpanError(span, trace.StatusCodeInternal, err)
+		return err
+	}
+
+	return nil
 }
 
 func (cms *Contentful) search(ctx context.Context, parameters SearchParameters) (searchResults, error) {
+	ctx, span := trace.StartSpan(ctx, "github.com/janivihervas/contentful-go.search")
+	defer span.End()
+
 	response := searchResults{}
 	if parameters.Values == nil {
 		parameters.Values = url.Values{}
 	}
 	parameters.Set("include", "10")
 
-	u := cms.url + "/spaces/" + cms.spaceID + "/entries?" + parameters.Encode()
-	req, err := http.NewRequest("GET", u, nil)
+	urlStr := cms.url + "/spaces/" + cms.spaceID + "/entries?" + parameters.Encode()
+	urlParsed, err := url.Parse(urlStr)
+	if err != nil {
+		addSpanError(span, trace.StatusCodeInternal, err)
+		return response, err
+	}
+
+	span.AddAttributes(trace.StringAttribute("http.host", urlParsed.Host))
+	span.AddAttributes(trace.StringAttribute("http.method", http.MethodGet))
+	span.AddAttributes(trace.StringAttribute("http.path", urlParsed.Path))
+	span.AddAttributes(trace.StringAttribute("http.query", urlParsed.RawQuery))
+
+	req, err := http.NewRequest(http.MethodGet, urlStr, nil)
 	if err != nil {
+		addSpanError(span, trace.StatusCodeInternal, err)
 		return response, err
 	}
 
 	req.Header.Add("Authorization", "Bearer "+cms.token)
 	req = req.WithContext(ctx)
 	resp, err := http.DefaultClient.Do(req)
+	if err == context.Canceled {
+		addSpanError(span, trace.StatusCodeCancelled, err)
+		return response, err
+	}
+	if err == context.DeadlineExceeded {
+		addSpanError(span, trace.StatusCodeDeadlineExceeded, err)
+		return response, err
+	}
 	if err != nil {
+		addSpanError(span, trace.StatusCodeUnknown, err)
 		return response, err
 	}
 	defer func() {
 		_ = resp.Body.Close()
 	}()
 
+	span.AddAttributes(trace.Int64Attribute("http.status_code", int64(resp.StatusCode)))
+
 	if resp.StatusCode == http.StatusTooManyRequests {
+		addSpanError(span, trace.StatusCodeResourceExhausted, ErrTooManyRequests)
 		seconds := retryAfter(ctx, resp)
 		if seconds == -1 {
+			addSpanError(span, trace.StatusCodeDeadlineExceeded, ErrTooManyRequests)
 			return response, ErrTooManyRequests
 		}
 
-		time.Sleep(time.Second * time.Duration(seconds))
-		return cms.search(ctx, parameters)
+		span.AddAttributes(trace.Int64Attribute("http.ratelimit_reset", int64(seconds)))
+
+		select {
+		case <-time.After(time.Second * time.Duration(seconds)):
+			return cms.search(ctx, parameters)
+		case <-ctx.Done():
+			addSpanError(span, trace.StatusCodeCancelled, err)
+			return response, ctx.Err()
+		}
 	}
 
 	if resp.StatusCode != http.StatusOK {
-		return response, fmt.Errorf("non-ok status code: %d", resp.StatusCode)
+		err = fmt.Errorf("non-ok status code: %d", resp.StatusCode)
+		addSpanError(span, trace.StatusCodeUnknown, err)
+		return response, err
 	}
 
 	err = json.NewDecoder(resp.Body).Decode(&response)
+	if err != nil {
+		addSpanError(span, trace.StatusCodeInternal, err)
+		return response, err
+	}
 
-	return response, err
+	return response, nil
 }
 
 func retryAfter(ctx context.Context, resp *http.Response) int {

span.go

@@ -0,0 +1,9 @@
+package contentful
+
+import "go.opencensus.io/trace"
+
+func addSpanError(span *trace.Span, statusCode int32, err error) {
+	span.SetStatus(trace.Status{Code: statusCode, Message: err.Error()})
+	// For Jaeger
+	span.AddAttributes(trace.BoolAttribute("error", true))
+}