4 Commits

Author SHA1 Message Date
06bf7ebca7 Add resource attributes to go_ metrics 2025-01-12 20:19:59 -05:00
15a597de1d Update TODO 2025-01-08 16:49:51 -05:00
56037c4b05 Support custom types 2025-01-08 16:48:34 -05:00
70ba85bf79 Add tests 2025-01-05 20:29:18 -05:00
9 changed files with 409 additions and 17 deletions

View File

@ -1,4 +1,8 @@
# TODO
- [ ] Unit tests
- [ ] HTTP Logging Middleware
- [x] Pattern for extending config
## Done
- [x] Unit tests
- [x] HTTP Logging Middleware
- [x] Fix panic with OTEL disabled

12
go.mod
View File

@ -30,7 +30,7 @@ require (
github.com/google/uuid v1.6.0 // indirect
github.com/grpc-ecosystem/grpc-gateway/v2 v2.25.1 // indirect
github.com/klauspost/compress v1.17.11 // indirect
github.com/mattn/go-colorable v0.1.13 // indirect
github.com/mattn/go-colorable v0.1.14 // indirect
github.com/mattn/go-isatty v0.0.20 // indirect
github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
github.com/prometheus/client_model v0.6.1 // indirect
@ -38,12 +38,12 @@ require (
github.com/prometheus/procfs v0.15.1 // indirect
go.opentelemetry.io/auto/sdk v1.1.0 // indirect
go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.33.0 // indirect
go.opentelemetry.io/proto/otlp v1.4.0 // indirect
golang.org/x/net v0.33.0 // indirect
go.opentelemetry.io/proto/otlp v1.5.0 // indirect
golang.org/x/net v0.34.0 // indirect
golang.org/x/sys v0.29.0 // indirect
golang.org/x/text v0.21.0 // indirect
google.golang.org/genproto/googleapis/api v0.0.0-20250102185135-69823020774d // indirect
google.golang.org/genproto/googleapis/rpc v0.0.0-20250102185135-69823020774d // indirect
google.golang.org/genproto/googleapis/api v0.0.0-20250106144421-5f5ef82da422 // indirect
google.golang.org/genproto/googleapis/rpc v0.0.0-20250106144421-5f5ef82da422 // indirect
google.golang.org/grpc v1.69.2 // indirect
google.golang.org/protobuf v1.36.1 // indirect
google.golang.org/protobuf v1.36.2 // indirect
)

12
go.sum
View File

@ -35,6 +35,8 @@ github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0
github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHPsaIE=
github.com/mattn/go-colorable v0.1.14/go.mod h1:6LmQG8QLFO4G5z1gPvYEzlUgJ2wF+stgPZH1UqBm1s8=
github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
@ -87,10 +89,14 @@ go.opentelemetry.io/otel/trace v1.33.0 h1:cCJuF7LRjUFso9LPnEAHJDB2pqzp+hbO8eu1qq
go.opentelemetry.io/otel/trace v1.33.0/go.mod h1:uIcdVUZMpTAmz0tI1z04GoVSezK37CbGV4fr1f2nBck=
go.opentelemetry.io/proto/otlp v1.4.0 h1:TA9WRvW6zMwP+Ssb6fLoUIuirti1gGbP28GcKG1jgeg=
go.opentelemetry.io/proto/otlp v1.4.0/go.mod h1:PPBWZIP98o2ElSqI35IHfu7hIhSwvc5N38Jw8pXuGFY=
go.opentelemetry.io/proto/otlp v1.5.0 h1:xJvq7gMzB31/d406fB8U5CBdyQGw4P399D1aQWU/3i4=
go.opentelemetry.io/proto/otlp v1.5.0/go.mod h1:keN8WnHxOy8PG0rQZjJJ5A2ebUoafqWp0eVQ4yIXvJ4=
go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
golang.org/x/net v0.33.0 h1:74SYHlV8BIgHIFC/LrYkOGIwL19eTYXQ5wc6TBuO36I=
golang.org/x/net v0.33.0/go.mod h1:HXLR5J+9DxmrqMwG9qjGCxZ+zKXxBru04zlTvWlWuN4=
golang.org/x/net v0.34.0 h1:Mb7Mrk043xzHgnRM88suvJFwzVrRfHEHJEl5/71CKw0=
golang.org/x/net v0.34.0/go.mod h1:di0qlW3YNM5oh6GqDGQr92MyTozJPmybPK4Ev/Gm31k=
golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@ -100,12 +106,18 @@ golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
google.golang.org/genproto/googleapis/api v0.0.0-20250102185135-69823020774d h1:H8tOf8XM88HvKqLTxe755haY6r1fqqzLbEnfrmLXlSA=
google.golang.org/genproto/googleapis/api v0.0.0-20250102185135-69823020774d/go.mod h1:2v7Z7gP2ZUOGsaFyxATQSRoBnKygqVq2Cwnvom7QiqY=
google.golang.org/genproto/googleapis/api v0.0.0-20250106144421-5f5ef82da422 h1:GVIKPyP/kLIyVOgOnTwFOrvQaQUzOzGMCxgFUOEmm24=
google.golang.org/genproto/googleapis/api v0.0.0-20250106144421-5f5ef82da422/go.mod h1:b6h1vNKhxaSoEI+5jc3PJUCustfli/mRab7295pY7rw=
google.golang.org/genproto/googleapis/rpc v0.0.0-20250102185135-69823020774d h1:xJJRGY7TJcvIlpSrN3K6LAWgNFUILlO+OMAqtg9aqnw=
google.golang.org/genproto/googleapis/rpc v0.0.0-20250102185135-69823020774d/go.mod h1:3ENsm/5D1mzDyhpzeRi1NR784I0BcofWBoSc5QqqMK4=
google.golang.org/genproto/googleapis/rpc v0.0.0-20250106144421-5f5ef82da422 h1:3UsHvIr4Wc2aW4brOaSCmcxh9ksica6fHEr8P1XhkYw=
google.golang.org/genproto/googleapis/rpc v0.0.0-20250106144421-5f5ef82da422/go.mod h1:3ENsm/5D1mzDyhpzeRi1NR784I0BcofWBoSc5QqqMK4=
google.golang.org/grpc v1.69.2 h1:U3S9QEtbXC0bYNvRtcoklF3xGtLViumSYxWykJS+7AU=
google.golang.org/grpc v1.69.2/go.mod h1:vyjdE6jLBI76dgpDojsFGNaHlxdjXN9ghpnd2o7JGZ4=
google.golang.org/protobuf v1.36.1 h1:yBPeRvTftaleIgM3PZ/WBIZ7XM/eEYAaEyCwvyjq/gk=
google.golang.org/protobuf v1.36.1/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
google.golang.org/protobuf v1.36.2 h1:R8FeyR1/eLmkutZOM5CWghmo5itiG9z0ktFlTVLuTmU=
google.golang.org/protobuf v1.36.2/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

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@ -23,3 +23,10 @@ func MustSetupConfigAndLogging(ctx context.Context) context.Context {
zerolog.Ctx(ctx).Trace().Any("config", *cfg).Send()
return ctx
}
// Unmarshal config into a custom type
// Type MUST include *config.AppConfig
// Stored in context as *config.AppConfig but can be asserted back
func MustSetupConfigAndLoggingInto[T any](ctx context.Context, into T) (context.Context, T) {
return ctx, into
}

107
pkg/app/setup_custom.go Normal file
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@ -0,0 +1,107 @@
package app
import (
"context"
"errors"
"flag"
"fmt"
"os"
"reflect"
"gopkg.in/yaml.v3"
"gitea.libretechconsulting.com/rmcguire/go-app/pkg/config"
)
// Used to unmarshal config and environment into a custom type
// that overloads *config.AppConfig. Will perform normal env
// substitutions for AppConfig, but env overrides for custom type
// are up to the caller.
func MustLoadConfigInto[T any](ctx context.Context, into T) (context.Context, T) {
// Step 1: Check our custom type for required *config.AppConfig
if err := hasAppConfig(into); err != nil {
panic(err)
}
// Step 2: Do the normal thing
ctx = MustSetupConfigAndLogging(ctx)
// Step 3: Extract the config
cfg := config.MustFromCtx(ctx)
// Step 4: Unmarshal custom config
configPath := flag.Lookup("config")
if configPath != nil && configPath.Value.String() != "" {
file, err := os.Open(configPath.Value.String())
if err != nil {
panic(fmt.Errorf("could not open config file: %w", err))
}
defer file.Close()
decoder := yaml.NewDecoder(file)
if err := decoder.Decode(into); err != nil {
panic(fmt.Errorf("could not decode config file: %w", err))
}
}
// Step 5: Re-apply AppConfig to custom type
if err := setAppConfig(into, cfg); err != nil {
panic(err)
}
// Step 6: Update context, return custom type
return ctx, into
}
func setAppConfig[T any](target T, appConfig *config.AppConfig) error {
// Ensure target is a pointer to a struct
v := reflect.ValueOf(target)
if v.Kind() != reflect.Ptr || v.IsNil() {
return errors.New("target must be a non-nil pointer to a struct")
}
v = v.Elem() // Dereference the pointer
if v.Kind() != reflect.Struct {
return errors.New("target must be a pointer to a struct")
}
// Replace *config.AppConfig
for i := 0; i < v.NumField(); i++ {
field := v.Field(i)
if field.Type() == reflect.TypeOf((*config.AppConfig)(nil)) {
if !field.CanSet() {
return fmt.Errorf("field %q cannot be set", v.Type().Field(i).Name)
}
field.Set(reflect.ValueOf(appConfig))
return nil
}
}
return errors.New("no *config.AppConfig field found in target struct")
}
func hasAppConfig[T any](target T) error {
v := reflect.ValueOf(target)
if v.Kind() != reflect.Ptr || v.IsNil() {
return errors.New("target must be a non-nil pointer to a struct")
}
v = v.Elem()
if v.Kind() != reflect.Struct {
return errors.New("target must be a pointer to a struct")
}
hasAppConfig := false
for i := 0; i < v.NumField(); i++ {
field := v.Type().Field(i)
if field.Type == reflect.TypeOf((*config.AppConfig)(nil)) {
hasAppConfig = true
break
}
}
if !hasAppConfig {
return errors.New("struct does not contain a *config.AppConfig field")
}
return nil
}

123
pkg/app/setup_test.go Normal file
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@ -0,0 +1,123 @@
package app
import (
"bufio"
"context"
"flag"
"io"
"os"
"regexp"
"testing"
"github.com/rs/zerolog"
"gitea.libretechconsulting.com/rmcguire/go-app/pkg/config"
)
func TestMustSetupConfigAndLogging(t *testing.T) {
// Configure app and logger
type inputs struct {
envs map[string]string
}
type outputs struct {
appName string
logLevel zerolog.Level
logRegexChecks []*regexp.Regexp
}
tests := []struct {
name string
inputs inputs
want outputs
}{
{
name: "Test json logging with short timestamp",
inputs: inputs{
envs: map[string]string{
"APP_NAME": "testapp",
"APP_LOG_LEVEL": "warn",
"APP_LOG_FORMAT": "json",
"APP_LOG_TIME_FORMAT": "short",
},
},
want: outputs{
appName: "testapp",
logLevel: zerolog.WarnLevel,
logRegexChecks: []*regexp.Regexp{
regexp.MustCompile(`^\{.*time":"\d{1,}:\d{2}`),
},
},
},
{
name: "Test json logging with unix timestamp",
inputs: inputs{
envs: map[string]string{
"APP_NAME": "testapp",
"APP_LOG_LEVEL": "info",
"APP_LOG_FORMAT": "json",
"APP_LOG_TIME_FORMAT": "unix",
},
},
want: outputs{
appName: "testapp",
logLevel: zerolog.InfoLevel,
logRegexChecks: []*regexp.Regexp{
regexp.MustCompile(`time":\d+,`),
},
},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
// Set environment variables
for key, val := range tt.inputs.envs {
os.Setenv(key, val)
}
// Prepare config in context
ctx := MustSetupConfigAndLogging(context.Background())
// Retrieve config and logger from prepared context
cfg := config.MustFromCtx(ctx)
logger := zerolog.Ctx(ctx)
// Check wants
if cfg.Name != tt.want.appName {
t.Errorf("Expected app name %s, got %s", tt.want.appName, cfg.Name)
}
if logger.GetLevel() != tt.want.logLevel {
t.Errorf("Expected log level %#v, got %#v", tt.want.logLevel, logger.GetLevel())
}
// Send and capture a log
r, w := io.Pipe()
testLogger := logger.Output(w)
scanner := bufio.NewScanner(r)
go func() {
testLogger.Error().Msg("test message")
w.Close()
}()
logOut := make([]byte, 0)
if scanner.Scan() {
logOut = scanner.Bytes()
}
// Check all expressions
for _, expr := range tt.want.logRegexChecks {
if !expr.Match(logOut) {
t.Errorf("Regex %s did not match log %s", expr.String(), logOut)
}
}
// Super annoying need to reset due to app framework package
// using flag.Parse() and go test also using it
testlog := flag.Lookup("test.testlogfile").Value.String()
flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError)
flag.String("test.testlogfile", testlog, "")
flag.String("test.paniconexit0", "", "")
flag.String("test.v", "", "")
flag.Parse()
})
}
}

81
pkg/config/config_test.go Normal file
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@ -0,0 +1,81 @@
package config
import (
"encoding/json"
"testing"
)
// Changing defaults could be a breaking change,
// if this needs to be modified to pass the test,
// an item should be added to the changelog.
//
// This should be maintained, as it is the primary
// interface between an app and the app framework.
var testDefaultConfig = &AppConfig{
Environment: "development",
Version: getVersion(),
Logging: &LogConfig{
Enabled: true,
Level: "info",
Format: LogFormatJSON,
Output: "stderr",
TimeFormat: TimeFormatLong,
},
HTTP: &HTTPConfig{
Listen: "127.0.0.1:8080",
LogRequests: false,
ReadTimeout: "10s",
WriteTimeout: "10s",
IdleTimeout: "1m",
},
OTEL: &OTELConfig{
Enabled: true,
PrometheusEnabled: true,
PrometheusPath: "/metrics",
StdoutEnabled: false,
MetricIntervalSecs: 30,
},
}
func Test_loadConfig(t *testing.T) {
type args struct {
configPath string
}
tests := []struct {
name string
args args
want *AppConfig
wantErr bool
}{
{
name: "Ensure defaults",
args: args{configPath: ""},
want: testDefaultConfig,
wantErr: false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got, err := loadConfig(tt.args.configPath)
if (err != nil) != tt.wantErr {
t.Errorf("loadConfig() error = %v, wantErr %v", err, tt.wantErr)
return
}
// Marshal both the expected and actual structs to JSON
gotJSON, err := json.Marshal(got)
if err != nil {
t.Fatalf("Failed to marshal got to JSON: %v", err)
}
wantJSON, err := json.Marshal(tt.want)
if err != nil {
t.Fatalf("Failed to marshal want to JSON: %v", err)
}
// Compare the JSON strings
if string(gotJSON) != string(wantJSON) {
t.Errorf("loadConfig() JSON = %s, want JSON = %s", string(gotJSON), string(wantJSON))
}
})
}
}

43
pkg/config/ctx_test.go Normal file
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@ -0,0 +1,43 @@
package config
import (
"context"
"testing"
)
func TestFromCtx(t *testing.T) {
app := &AppConfig{
Name: "testapp",
}
appCtx := app.AddToCtx(context.Background())
type args struct {
ctx context.Context
}
tests := []struct {
name string
args args
wantErr bool
}{
{
name: "Unprepared app context",
args: args{ctx: context.Background()},
wantErr: true,
},
{
name: "Prepared app context",
args: args{ctx: appCtx},
wantErr: false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
_, err := FromCtx(tt.args.ctx)
if (err != nil) != tt.wantErr {
t.Errorf("FromCtx() error = %v, wantErr %v", err, tt.wantErr)
return
}
})
}
}

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@ -8,6 +8,7 @@ import (
"time"
opentelemetry "go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
"go.opentelemetry.io/otel/exporters/prometheus"
@ -46,6 +47,11 @@ func Init(ctx context.Context) (context.Context, func(context.Context) error) {
if !cfg.OTEL.Enabled {
opentelemetry.SetMeterProvider(noopMetric.NewMeterProvider())
opentelemetry.SetTracerProvider(noop.NewTracerProvider())
// Won't function with noop providers
meter := opentelemetry.Meter(cfg.Name)
ctx = AddMeterToCtx(ctx, meter)
tracer := opentelemetry.Tracer(cfg.Name)
ctx = AddTracerToCtx(ctx, tracer)
return ctx, func(context.Context) error {
return nil
}
@ -62,12 +68,12 @@ func Init(ctx context.Context) (context.Context, func(context.Context) error) {
if cfg.OTEL.StdoutEnabled {
options = append(options, EnableStdoutExporter)
}
if cfg.OTEL.MetricIntervalSecs > 0 {
metricInterval = time.Duration(cfg.OTEL.MetricIntervalSecs) * time.Second
}
if cfg.OTEL.PrometheusEnabled {
options = append(options, EnablePrometheusExporter)
}
if cfg.OTEL.MetricIntervalSecs > 0 {
metricInterval = time.Duration(cfg.OTEL.MetricIntervalSecs) * time.Second
}
options = append(options,
WithMetricExportInterval(metricInterval))
@ -134,7 +140,7 @@ func newPropagator() propagation.TextMapPropagator {
func (s *settings) newTracerProvider(ctx context.Context) (traceProvider *traceSDK.TracerProvider, err error) {
traceOpts := []traceSDK.TracerProviderOption{
traceSDK.WithResource(newResource()),
traceSDK.WithResource(newResource(ctx)),
}
host, set := os.LookupEnv("OTEL_EXPORTER_OTLP_ENDPOINT")
@ -159,8 +165,15 @@ func (s *settings) newTracerProvider(ctx context.Context) (traceProvider *traceS
return
}
func newResource() *resource.Resource {
return resource.NewWithAttributes(semconv.SchemaURL)
func newResource(ctx context.Context) *resource.Resource {
cfg := config.MustFromCtx(ctx)
attributes := []attribute.KeyValue{
semconv.ServiceName(cfg.Name),
semconv.ServiceVersion(cfg.Version),
semconv.K8SPodName(os.Getenv("HOSTNAME")),
}
return resource.NewWithAttributes(semconv.SchemaURL, attributes...)
}
// Configures meter provider
@ -168,7 +181,9 @@ func newResource() *resource.Resource {
// Conditionally provides an OTLP metrics exporter
func (s *settings) newMeterProvider(ctx context.Context) (*metric.MeterProvider, error) {
// OTEL Prometheus Exporter
exporter, err := prometheus.New()
exporter, err := prometheus.New(
prometheus.WithResourceAsConstantLabels(attribute.NewDenyKeysFilter()),
)
if err != nil {
return nil, err
}
@ -197,6 +212,7 @@ func (s *settings) newMeterProvider(ctx context.Context) (*metric.MeterProvider,
var meterProvider *metric.MeterProvider
if otlpExporter != nil {
metricOptions = append(metricOptions,
metric.WithResource(newResource(ctx)),
metric.WithReader(exporter),
metric.WithReader(
metric.NewPeriodicReader(
@ -204,12 +220,11 @@ func (s *settings) newMeterProvider(ctx context.Context) (*metric.MeterProvider,
metric.WithInterval(s.MetricExportInterval),
),
),
metric.WithResource(newResource()),
)
} else {
metricOptions = append(metricOptions,
metric.WithResource(newResource(ctx)),
metric.WithReader(exporter),
metric.WithResource(newResource()),
)
}