Updates for jaeger tracing client.

vendor/github.com/uber/jaeger-client-go/config/config_env.go

@@ -0,0 +1,205 @@
+// Copyright (c) 2018 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	opentracing "github.com/opentracing/opentracing-go"
+	"github.com/pkg/errors"
+
+	"github.com/uber/jaeger-client-go"
+)
+
+const (
+	// environment variable names
+	envServiceName            = "JAEGER_SERVICE_NAME"
+	envDisabled               = "JAEGER_DISABLED"
+	envRPCMetrics             = "JAEGER_RPC_METRICS"
+	envTags                   = "JAEGER_TAGS"
+	envSamplerType            = "JAEGER_SAMPLER_TYPE"
+	envSamplerParam           = "JAEGER_SAMPLER_PARAM"
+	envSamplerManagerHostPort = "JAEGER_SAMPLER_MANAGER_HOST_PORT"
+	envSamplerMaxOperations   = "JAEGER_SAMPLER_MAX_OPERATIONS"
+	envSamplerRefreshInterval = "JAEGER_SAMPLER_REFRESH_INTERVAL"
+	envReporterMaxQueueSize   = "JAEGER_REPORTER_MAX_QUEUE_SIZE"
+	envReporterFlushInterval  = "JAEGER_REPORTER_FLUSH_INTERVAL"
+	envReporterLogSpans       = "JAEGER_REPORTER_LOG_SPANS"
+	envAgentHost              = "JAEGER_AGENT_HOST"
+	envAgentPort              = "JAEGER_AGENT_PORT"
+)
+
+// FromEnv uses environment variables to set the tracer's Configuration
+func FromEnv() (*Configuration, error) {
+	c := &Configuration{}
+
+	if e := os.Getenv(envServiceName); e != "" {
+		c.ServiceName = e
+	}
+
+	if e := os.Getenv(envRPCMetrics); e != "" {
+		if value, err := strconv.ParseBool(e); err == nil {
+			c.RPCMetrics = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envRPCMetrics, e)
+		}
+	}
+
+	if e := os.Getenv(envDisabled); e != "" {
+		if value, err := strconv.ParseBool(e); err == nil {
+			c.Disabled = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envDisabled, e)
+		}
+	}
+
+	if e := os.Getenv(envTags); e != "" {
+		c.Tags = parseTags(e)
+	}
+
+	if s, err := samplerConfigFromEnv(); err == nil {
+		c.Sampler = s
+	} else {
+		return nil, errors.Wrap(err, "cannot obtain sampler config from env")
+	}
+
+	if r, err := reporterConfigFromEnv(); err == nil {
+		c.Reporter = r
+	} else {
+		return nil, errors.Wrap(err, "cannot obtain reporter config from env")
+	}
+
+	return c, nil
+}
+
+// samplerConfigFromEnv creates a new SamplerConfig based on the environment variables
+func samplerConfigFromEnv() (*SamplerConfig, error) {
+	sc := &SamplerConfig{}
+
+	if e := os.Getenv(envSamplerType); e != "" {
+		sc.Type = e
+	}
+
+	if e := os.Getenv(envSamplerParam); e != "" {
+		if value, err := strconv.ParseFloat(e, 64); err == nil {
+			sc.Param = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envSamplerParam, e)
+		}
+	}
+
+	if e := os.Getenv(envSamplerManagerHostPort); e != "" {
+		sc.SamplingServerURL = e
+	}
+
+	if e := os.Getenv(envSamplerMaxOperations); e != "" {
+		if value, err := strconv.ParseInt(e, 10, 0); err == nil {
+			sc.MaxOperations = int(value)
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envSamplerMaxOperations, e)
+		}
+	}
+
+	if e := os.Getenv(envSamplerRefreshInterval); e != "" {
+		if value, err := time.ParseDuration(e); err == nil {
+			sc.SamplingRefreshInterval = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envSamplerRefreshInterval, e)
+		}
+	}
+
+	return sc, nil
+}
+
+// reporterConfigFromEnv creates a new ReporterConfig based on the environment variables
+func reporterConfigFromEnv() (*ReporterConfig, error) {
+	rc := &ReporterConfig{}
+
+	if e := os.Getenv(envReporterMaxQueueSize); e != "" {
+		if value, err := strconv.ParseInt(e, 10, 0); err == nil {
+			rc.QueueSize = int(value)
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envReporterMaxQueueSize, e)
+		}
+	}
+
+	if e := os.Getenv(envReporterFlushInterval); e != "" {
+		if value, err := time.ParseDuration(e); err == nil {
+			rc.BufferFlushInterval = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envReporterFlushInterval, e)
+		}
+	}
+
+	if e := os.Getenv(envReporterLogSpans); e != "" {
+		if value, err := strconv.ParseBool(e); err == nil {
+			rc.LogSpans = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envReporterLogSpans, e)
+		}
+	}
+
+	host := jaeger.DefaultUDPSpanServerHost
+	if e := os.Getenv(envAgentHost); e != "" {
+		host = e
+	}
+
+	port := jaeger.DefaultUDPSpanServerPort
+	if e := os.Getenv(envAgentPort); e != "" {
+		if value, err := strconv.ParseInt(e, 10, 0); err == nil {
+			port = int(value)
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envAgentPort, e)
+		}
+	}
+
+	// the side effect of this is that we are building the default value, even if none of the env vars
+	// were not explicitly passed
+	rc.LocalAgentHostPort = fmt.Sprintf("%s:%d", host, port)
+
+	return rc, nil
+}
+
+// parseTags parses the given string into a collection of Tags.
+// Spec for this value:
+// - comma separated list of key=value
+// - value can be specified using the notation ${envVar:defaultValue}, where `envVar`
+// is an environment variable and `defaultValue` is the value to use in case the env var is not set
+func parseTags(sTags string) []opentracing.Tag {
+	pairs := strings.Split(sTags, ",")
+	tags := make([]opentracing.Tag, 0)
+	for _, p := range pairs {
+		kv := strings.SplitN(p, "=", 2)
+		k, v := strings.TrimSpace(kv[0]), strings.TrimSpace(kv[1])
+
+		if strings.HasPrefix(v, "${") && strings.HasSuffix(v, "}") {
+			ed := strings.SplitN(v[2:len(v)-1], ":", 2)
+			e, d := ed[0], ed[1]
+			v = os.Getenv(e)
+			if v == "" && d != "" {
+				v = d
+			}
+		}
+
+		tag := opentracing.Tag{Key: k, Value: v}
+		tags = append(tags, tag)
+	}
+
+	return tags
+}