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Add env var SPLUNK_CONFIG_YAML for storing configuration YAML (open-t…
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…elemetry#462)
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@bjsignalfx
bjsignalfx authored Jul 14, 2021
1 parent 6d28ae8 commit f60a618
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Showing 6 changed files with 341 additions and 88 deletions.
168 changes: 103 additions & 65 deletions cmd/otelcol/main.go
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@
package main

import (
"bytes"
"fmt"
"log"
"os"
Expand All @@ -26,6 +27,7 @@ import (

"go.opentelemetry.io/collector/component"
"go.opentelemetry.io/collector/service"
"go.opentelemetry.io/collector/service/parserprovider"
"go.uber.org/zap"

"github.com/signalfx/splunk-otel-collector/internal/components"
Expand All @@ -37,6 +39,7 @@ import (
const (
ballastEnvVarName = "SPLUNK_BALLAST_SIZE_MIB"
configEnvVarName = "SPLUNK_CONFIG"
configYamlEnvVarName = "SPLUNK_CONFIG_YAML"
configServerEnabledEnvVar = "SPLUNK_DEBUG_CONFIG_SERVER"
memLimitMiBEnvVarName = "SPLUNK_MEMORY_LIMIT_MIB"
memTotalEnvVarName = "SPLUNK_MEMORY_TOTAL_MIB"
Expand All @@ -57,8 +60,7 @@ func main() {
// TODO: Use same format as the collector
log.SetFlags(log.Ldate | log.Ltime | log.Lshortfile)

args := os.Args[1:]
if !contains(args, "-h") && !contains(args, "--help") {
if !contains(os.Args[1:], "-h") && !contains(os.Args[1:], "--help") {
checkRuntimeParams()
}

Expand All @@ -77,6 +79,7 @@ func main() {
}

parserProvider := configprovider.NewConfigSourceParserProvider(
newBaseParserProvider(),
zap.NewNop(), // The service logger is not available yet, setting it to NoP.
info,
configsources.Get()...,
Expand Down Expand Up @@ -109,44 +112,29 @@ func contains(arr []string, str string) bool {

// Get the value of a key in an array
// Support key/value with and with an equal sign
func getKeyValue(args []string, argName string) string {
val := ""
for i, arg := range args {
func getKeyValue(args []string, arg string) (exists bool, value string) {
argEq := arg + "="
for i := range args {
switch {
case strings.HasPrefix(arg, argName+"="):
s := strings.Split(arg, "=")
val = s[1]
case arg == argName:
i++
val = args[i]
case strings.HasPrefix(args[i], argEq):
return true, strings.SplitN(args[i], "=", 2)[1]
case args[i] == arg:
exists = true
if i < (len(args) - 1) {
value = args[i+1]
}
return
}
}
return val
return
}

// Check runtime parameters
// Runtime parameters take priority over environment variables
// Config and ballast flags are checked
// Config and all memory env vars are checked
func checkRuntimeParams() {
args := os.Args[1:]
config := ""

// Check if config flag was passed and its value differs from config env var.
// If so, log that it will be used instead of env var value and set env var with that value.
// This allows users to set `--config` and have it take priority when running from most contexts.
cliConfig := getKeyValue(args, "--config")
if cliConfig != "" {
config = os.Getenv(configEnvVarName)
if config != "" && config != cliConfig {
log.Printf(
"Both %v and '--config' were specified. Overriding %q environment variable value with %q for this session",
configEnvVarName, config, cliConfig,
)
}
os.Setenv(configEnvVarName, cliConfig)
}
setConfig()
checkConfig()

// Set default total memory
memTotalSizeMiB := defaultMemoryTotalMiB
Expand All @@ -169,66 +157,103 @@ func checkRuntimeParams() {
// Check if memory ballast flag was passed
// If so, ensure memory ballast env var is not set
// Then set memory ballast and limit properly
ballastSize := getKeyValue(args, "--mem-ballast-size-mib")
_, ballastSize := getKeyValue(os.Args[1:], "--mem-ballast-size-mib")
if ballastSize != "" {
config = os.Getenv(ballastEnvVarName)
if config != "" {
log.Fatalf("Both %v and '--config' were specified, but only one is allowed", ballastEnvVarName)
if os.Getenv(ballastEnvVarName) != "" {
log.Fatalf("Both %v and '--mem-ballast-size-mib' were specified, but only one is allowed", ballastEnvVarName)
}
os.Setenv(ballastEnvVarName, ballastSize)
}
setMemoryBallast(memTotalSizeMiB)
setMemoryLimit(memTotalSizeMiB)
}

// Validate and set the configuration
func setConfig() {
// Check if the config is specified via the env var.
config := os.Getenv(configEnvVarName)
// If not attempt to use a default config; supports Docker and local
if config == "" {
_, err := os.Stat(defaultDockerSAPMConfig)
if err == nil {
config = defaultDockerSAPMConfig
// Sets flag '--config' to specified env var SPLUNK_CONFIG, if the flag not specified.
// Logs a message and returns if env var SPLUNK_CONFIG_YAML specified, and '--config' and SPLUNK_CONFIG no specified.
// Sets '--config' to default config file path if '--config', SPLUNK_CONFIG and SPLUNK_CONFIG_YAML not specified.
func checkConfig() {
configPathFlagExists, configPathFlag := getKeyValue(os.Args[1:], "--config")
configPathVar := os.Getenv(configEnvVarName)
configYaml := os.Getenv(configYamlEnvVarName)

if configPathFlagExists && configPathFlag == "" {
log.Fatal("Command line flag --config specified but empty")
}

if configPathFlag != "" {
if _, err := os.Stat(configPathFlag); err != nil {
log.Fatalf("Unable to find the configuration file (%s) ensure flag '--config' is set properly", configPathFlag)
}
_, err = os.Stat(defaultLocalSAPMConfig)
if err == nil {
config = defaultLocalSAPMConfig

if configPathVar != "" && configPathVar != configPathFlag {
log.Printf("Both environment variable %v and flag '--config' were specified. Using the flag value %s and ignoring the environment variable value %s in this session", configEnvVarName, configPathFlag, configPathVar)
}
if config == "" {
log.Fatalf("Unable to find the default configuration file, ensure %s environment variable is set properly", configEnvVarName)

if configYaml != "" {
log.Printf("Both environment variable %s and flag '--config' were specified. Using the flag value %s and ignoring the environment variable in this session", configYamlEnvVarName, configPathFlag)
}
} else {
// Check if file exists.
_, err := os.Stat(config)
if err != nil {
log.Fatalf("Unable to find the configuration file (%s) ensure %s environment variable is set properly", config, configEnvVarName)

checkRequiredEnvVars(configPathFlag)

log.Printf("Set config to %v", configPathFlag)
return
}

if configPathVar != "" {
if _, err := os.Stat(configPathVar); err != nil {
log.Fatalf("Unable to find the configuration file (%s) ensure %s environment variable is set properly", configPathVar, configEnvVarName)
}

os.Args = append(os.Args, "--config="+configPathVar)

if configYaml != "" {
log.Printf("Both %s and %s were specified. Using %s environment variable value %s for this session", configEnvVarName, configYamlEnvVarName, configEnvVarName, configPathVar)
}

checkRequiredEnvVars(configPathVar)

log.Printf("Set config to %v", configPathVar)
return
}

if configYaml != "" {
log.Printf("Using environment variable %s for configuration", configYamlEnvVarName)
return
}

defaultConfigPath := getExistingDefaultConfigPath()
checkRequiredEnvVars(defaultConfigPath)
os.Args = append(os.Args, "--config="+defaultConfigPath)
log.Printf("Set config to %v", defaultConfigPath)
}

func getExistingDefaultConfigPath() (path string) {
if _, err := os.Stat(defaultLocalSAPMConfig); err == nil {
return defaultLocalSAPMConfig
}
if _, err := os.Stat(defaultDockerSAPMConfig); err == nil {
return defaultDockerSAPMConfig
}
log.Fatalf("Unable to find the default configuration file (%s) or (%s)", defaultLocalSAPMConfig, defaultDockerSAPMConfig)
return
}

switch config {
func checkRequiredEnvVars(path string) {
// Check environment variables required by default configuration.
switch path {
case
defaultDockerSAPMConfig,
defaultDockerOTLPConfig,
defaultLocalSAPMConfig,
defaultLocalOTLPConfig:
// The following environment variables are required.
// If any are missing stop here.
requiredEnvVars := []string{realmEnvVarName, tokenEnvVarName}
for _, v := range requiredEnvVars {
if len(os.Getenv(v)) == 0 {
log.Printf("Usage: %s=12345 %s=us0 %s", tokenEnvVarName, realmEnvVarName, os.Args[0])
log.Fatalf("ERROR: Missing required environment variable %s with default config path %s", v, config)
log.Fatalf("ERROR: Missing required environment variable %s with default config path %s", v, path)
}
}
}

args := os.Args[1:]
if !contains(args, "--config") {
// Inject the command line flag that controls the configuration.
os.Args = append(os.Args, "--config="+config)
}
log.Printf("Set config to %v", config)
}

// Validate and set the memory ballast
Expand Down Expand Up @@ -277,7 +302,7 @@ func setMemoryLimit(memTotalSizeMiB int) {

// Validate memoryLimit is sane
args := os.Args[1:]
b := getKeyValue(args, "--mem-ballast-size-mib")
_, b := getKeyValue(args, "--mem-ballast-size-mib")
ballastSize, _ := strconv.Atoi(b)
if (ballastSize * 2) > memLimit {
log.Fatalf("Memory limit (%v) is less than 2x ballast (%v). Increase memory limit or decrease ballast size.", memLimit, ballastSize)
Expand All @@ -287,6 +312,19 @@ func setMemoryLimit(memTotalSizeMiB int) {
log.Printf("Set memory limit to %d MiB", memLimit)
}

// Returns a ParserProvider that reads configuration YAML from an environment variable when applicable.
func newBaseParserProvider() parserprovider.ParserProvider {
_, configPathFlag := getKeyValue(os.Args[1:], "--config")
configPathVar := os.Getenv(configEnvVarName)
configYaml := os.Getenv(configYamlEnvVarName)

if configPathFlag == "" && configPathVar == "" && configYaml != "" {
return parserprovider.NewInMemory(bytes.NewBufferString(configYaml))
}

return parserprovider.Default()
}

func runInteractive(params service.CollectorSettings) error {
app, err := service.New(params)
if err != nil {
Expand Down
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