// Unless explicitly stated otherwise all files in this repository are licensed
// under the Apache License Version 2.0.
// This product includes software developed at Datadog (https://www.datadoghq.com/).
// Copyright 2022 Datadog, Inc.
package internal
import (
"net"
"net/http"
"net/url"
"os"
"time"
"github.com/DataDog/dd-trace-go/v2/internal/env"
"github.com/DataDog/dd-trace-go/v2/internal/log"
// OTel did a breaking change to the module go.opentelemetry.io/collector/pdata which is imported by the agent
// and go.opentelemetry.io/collector/pdata/pprofile depends on it and is breaking because of it
// For some reason the dependency closure won't let use upgrade this module past the point where it does not break anymore
// So we are forced to add a blank import of this module to give us back the control over its version
//
// TODO: remove this once github.com/datadog-agent/pkg/trace has upgraded both modules past the breaking change
_ "go.opentelemetry.io/collector/pdata/pprofile"
)
const (
DefaultAgentHostname = "localhost"
DefaultTraceAgentPort = "8126"
)
// This is a variable rather than a constant so it can be replaced in unit tests
var DefaultTraceAgentUDSPath = "/var/run/datadog/apm.socket"
// AgentURLFromEnv resolves the URL for the trace agent based on
// the default host/port and UDS path, and via standard environment variables.
// AgentURLFromEnv has the following priority order:
// - First, DD_TRACE_AGENT_URL if it is set
// - Then, if either of DD_AGENT_HOST and DD_TRACE_AGENT_PORT are set,
// use http://DD_AGENT_HOST:DD_TRACE_AGENT_PORT,
// defaulting to localhost and 8126, respectively
// - Then, DefaultTraceAgentUDSPath, if the path exists
// - Finally, localhost:8126
func AgentURLFromEnv() *url.URL {
if agentURL := env.Get("DD_TRACE_AGENT_URL"); agentURL != "" {
u, err := url.Parse(agentURL)
if err != nil {
log.Warn("Failed to parse DD_TRACE_AGENT_URL: %s", err.Error())
} else {
switch u.Scheme {
case "unix", "http", "https":
return u
default:
log.Warn("Unsupported protocol %q in Agent URL %q. Must be one of: http, https, unix.", u.Scheme, agentURL)
}
}
}
host, providedHost := env.Lookup("DD_AGENT_HOST")
port, providedPort := env.Lookup("DD_TRACE_AGENT_PORT")
if host == "" {
// We treat set but empty the same as unset
providedHost = false
host = DefaultAgentHostname
}
if port == "" {
// We treat set but empty the same as unset
providedPort = false
port = DefaultTraceAgentPort
}
httpURL := &url.URL{
Scheme: "http",
Host: net.JoinHostPort(host, port),
}
if providedHost || providedPort {
return httpURL
}
if _, err := os.Stat(DefaultTraceAgentUDSPath); err == nil {
return &url.URL{
Scheme: "unix",
Path: DefaultTraceAgentUDSPath,
}
}
return httpURL
}
func DefaultDialer(timeout time.Duration) *net.Dialer {
return &net.Dialer{
Timeout: timeout,
KeepAlive: 30 * time.Second,
DualStack: true,
}
}
func DefaultHTTPClient(timeout time.Duration, disableKeepAlives bool) *http.Client {
return &http.Client{
Transport: &http.Transport{
Proxy: http.ProxyFromEnvironment,
DialContext: DefaultDialer(timeout).DialContext,
MaxIdleConns: 100,
IdleConnTimeout: 90 * time.Second,
TLSHandshakeTimeout: 10 * time.Second,
ExpectContinueTimeout: 1 * time.Second,
DisableKeepAlives: disableKeepAlives,
},
Timeout: timeout,
}
}
