From c940ac4f72e7e55ef1a7aa35cc0fc32684716977 Mon Sep 17 00:00:00 2001 From: dakkar Date: Thu, 19 Dec 2024 09:42:17 +0000 Subject: minimal example --- .gitignore | 5 ++ .golangci.yml | 56 +++++++++++++++++++++ Makefile | 34 +++++++++++++ README.md | 27 ++++++++++ cmd/main/main.go | 33 +++++++++++++ config/config.go | 126 +++++++++++++++++++++++++++++++++++++++++++++++ example.development.json | 5 ++ factory/factory.go | 33 +++++++++++++ go.mod | 29 +++++++++++ go.sum | 68 +++++++++++++++++++++++++ logging/logging.go | 43 ++++++++++++++++ something/something.go | 23 +++++++++ 12 files changed, 482 insertions(+) create mode 100644 .gitignore create mode 100644 .golangci.yml create mode 100644 Makefile create mode 100644 README.md create mode 100644 cmd/main/main.go create mode 100644 config/config.go create mode 100644 example.development.json create mode 100644 factory/factory.go create mode 100644 go.mod create mode 100644 go.sum create mode 100644 logging/logging.go create mode 100644 something/something.go diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..ac21027 --- /dev/null +++ b/.gitignore @@ -0,0 +1,5 @@ +*~ +*.sw? +/*.tar.gz +/go-example +/cover.html diff --git a/.golangci.yml b/.golangci.yml new file mode 100644 index 0000000..3fcf71e --- /dev/null +++ b/.golangci.yml @@ -0,0 +1,56 @@ +--- +output: + sort-results: true + +run: + go: "1.23" + +linters-settings: + goimports: + local-prefixes: www.thenautilus.net/cgit + + gci: + sections: + - standard + - default + - prefix(www.thenautilus.net/cgit) + + misspell: + locale: "UK" + + varnamelen: + ignore-names: + - ok + - w + - r + + wsl: + # sometimes I really have to start a block with a comment! + allow-separated-leading-comment: true + + +linters: + disable: + - ireturn # we should return concrete types, not interfaces, but I + # can't quite figure out how to do it... + - exhaustruct + - forbidigo + - depguard + - mnd + - nonamedreturns + presets: + - style + - bugs + - error + - format + - import + - module + - performance + - unused + + +issues: + exclude: + - 'package should be `\w+_test`' + - 'package comment should not have leading space' + diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..1ee128f --- /dev/null +++ b/Makefile @@ -0,0 +1,34 @@ +TARGET = go-example +RUN_MODE ?= development +GO ?= go + +$(TARGET): */*.go go.sum + $(GO) build -o $@ ./cmd/main/ + +.PHONY: test +test: + $(GO) test -cover -coverprofile=coverage.out -v ./... + $(GO) tool cover -html=coverage.out -o cover.html + rm coverage.out + +.PHONY: lint +lint: fmt + ~/go/bin/golangci-lint run -v + +.PHONY: clean +clean: + rm $(TARGET) + +.PHONY: fmt +fmt: + ~/go/bin/goimports -local www.thenautilus.net/cgit -w . + ~/go/bin/gci write -s Standard -s Default -s 'Prefix(www.thenautilus.net/cgit)' . + ~/go/bin/gofumpt -l -w . + +.PHONY: run +run: $(TARGET) + ./$(TARGET) --verbose --log-format=console $(ARGS) + +.PHONY: update +update: + go get -u -t ./... diff --git a/README.md b/README.md new file mode 100644 index 0000000..78052d6 --- /dev/null +++ b/README.md @@ -0,0 +1,27 @@ +# A Go example + +You'll need `go` 1.23 at least. + +There's a [`Makefile`](Makefile), so you can do: + + $ make clean + $ make test + $ make + $ make run + +If you run: + + go install golang.org/x/tools/cmd/goimports@latest + go install github.com/daixiang0/gci@latest + go install mvdan.cc/gofumpt@latest + +then you can do `make fmt` to format all the source files. + +If you `go install +github.com/golangci/golangci-lint/cmd/golangci-lint@latest`, you can +also do `make lint` to get a linting / critique of all the source +files (`lint` runs `fmt` first, so you need to have installed the +packages above as well). + +Note that the `Makefile` is *for development*, it's not used on +production machines. diff --git a/cmd/main/main.go b/cmd/main/main.go new file mode 100644 index 0000000..ac7f788 --- /dev/null +++ b/cmd/main/main.go @@ -0,0 +1,33 @@ +package main + +import ( + "fmt" + "os" + + "www.thenautilus.net/cgit/go-example/config" + factorypkg "www.thenautilus.net/cgit/go-example/factory" + "www.thenautilus.net/cgit/go-example/logging" +) + +func main() { + // this is the main binary, so the config file is in + // the same directory as the executable + config, err := config.GetMainConfig(".") + if err != nil { + fmt.Fprintf(os.Stderr, "%s\n", err) + os.Exit(1) + } + + log := logging.Logger(config.Logger) + + log.Info().Object("config", &config).Msg("configuration") + + factory := factorypkg.New(log, &config) + + something := factory.Something() + + err = something.DoSomething() + if err != nil { + log.Error().Err(err).Msg("Can't do the thing") + } +} diff --git a/config/config.go b/config/config.go new file mode 100644 index 0000000..3c93d53 --- /dev/null +++ b/config/config.go @@ -0,0 +1,126 @@ +package config + +import ( + "errors" + "fmt" + "os" + "path" + "strings" + + "github.com/mitchellh/mapstructure" + "github.com/rs/zerolog" + "github.com/spf13/pflag" + "github.com/spf13/viper" +) + +type LoggerConfig struct { + Verbose bool `mapstructure:"verbose"` + Format string `mapstructure:"format"` +} + +func (c *LoggerConfig) MarshalZerologObject(e *zerolog.Event) { + e. + Bool("verbose", c.Verbose). + Str("format", c.Format) +} + +type SomethingConfig struct { + Value int `mapstructure:"value"` +} + +func (c *SomethingConfig) MarshalZerologObject(event *zerolog.Event) { + event. + Int("value", c.Value) +} + +type MainConfig struct { + Something SomethingConfig `mapstructure:"something"` + Logger LoggerConfig `mapstructure:"logger"` + + configFile string +} + +func (c *MainConfig) MarshalZerologObject(event *zerolog.Event) { + event. + Str("config-file", c.configFile). + Object("logger", &c.Logger). + Object("something", &c.Something) +} + +func addLoggerOptions() { + pflag.Bool("verbose", false, "log at debug level") + viper.BindPFlag("logger.verbose", pflag.Lookup("verbose")) //nolint:errcheck + pflag.String("log-format", "json", "logging format (json, console)") + viper.BindPFlag("logger.format", pflag.Lookup("log-format")) //nolint:errcheck +} + +func addSomethingOptions() { + pflag.Int("something-value", 123, "value used to do something") + viper.BindPFlag("something.value", pflag.Lookup("something-value")) //nolint:errcheck + viper.BindEnv("something.value", "SOMETHING_VALUE") //nolint:errcheck +} + +func addConfigFromFile(configRelPath string) error { + mode := os.Getenv("RUN_MODE") + if mode == "" { + mode = "development" + } + + viper.SetConfigName("example." + mode) + + myName, err := os.Executable() + if err == nil && !strings.HasPrefix(configRelPath, "/") { + myDir := path.Dir(myName) + viper.AddConfigPath(path.Join(myDir, configRelPath)) + } else { + viper.AddConfigPath(configRelPath) + } + + err = viper.ReadInConfig() + if err != nil { + var notFound viper.ConfigFileNotFoundError + if !errors.As(err, ¬Found) { + return fmt.Errorf("failed to read config file at %s: %w", viper.ConfigFileUsed(), err) + } + } + + return nil +} + +func loadConfigFromFile(path string) (MainConfig, error) { + pathFromEnv := os.Getenv("EXAMPLE_CONFIG") + if pathFromEnv != "" { + path = pathFromEnv + } + + err := addConfigFromFile(path) + if err != nil { + return MainConfig{}, err + } + + var config MainConfig + + err = viper.Unmarshal(&config, viper.DecodeHook( + mapstructure.ComposeDecodeHookFunc( + mapstructure.StringToTimeDurationHookFunc(), + mapstructure.StringToIPHookFunc(), + ), + )) + if err != nil { + return MainConfig{}, fmt.Errorf("failed to parse options: %w", err) + } + + config.configFile = viper.ConfigFileUsed() + + return config, nil +} + +func GetMainConfig(path string) (MainConfig, error) { + addLoggerOptions() + addSomethingOptions() + + pflag.Parse() + viper.BindPFlags(pflag.CommandLine) //nolint:errcheck + + return loadConfigFromFile(path) +} diff --git a/example.development.json b/example.development.json new file mode 100644 index 0000000..6c45101 --- /dev/null +++ b/example.development.json @@ -0,0 +1,5 @@ +{ + "something": { + "value": 42 + } +} diff --git a/factory/factory.go b/factory/factory.go new file mode 100644 index 0000000..ae84911 --- /dev/null +++ b/factory/factory.go @@ -0,0 +1,33 @@ +package factory + +import ( + "github.com/rs/zerolog" + + "www.thenautilus.net/cgit/go-example/config" + "www.thenautilus.net/cgit/go-example/something" +) + +type Factory struct { + something *something.Something + + config *config.MainConfig + logger zerolog.Logger +} + +func New(logger zerolog.Logger, config *config.MainConfig) Factory { + return Factory{ + config: config, + logger: logger, + } +} + +func (f *Factory) Something() *something.Something { + if f.something == nil { + something := something.New( + &f.config.Something, + ) + f.something = &something + } + + return f.something +} diff --git a/go.mod b/go.mod new file mode 100644 index 0000000..e4fcf67 --- /dev/null +++ b/go.mod @@ -0,0 +1,29 @@ +module www.thenautilus.net/cgit/go-example + +go 1.23 + +require ( + github.com/fsnotify/fsnotify v1.7.0 // indirect + github.com/hashicorp/hcl v1.0.0 // indirect + github.com/magiconair/properties v1.8.7 // indirect + github.com/mattn/go-colorable v0.1.13 // indirect + github.com/mattn/go-isatty v0.0.19 // indirect + github.com/mitchellh/mapstructure v1.5.0 // indirect + github.com/pelletier/go-toml/v2 v2.2.2 // indirect + github.com/rs/zerolog v1.33.0 // indirect + github.com/sagikazarmark/locafero v0.4.0 // indirect + github.com/sagikazarmark/slog-shim v0.1.0 // indirect + github.com/sourcegraph/conc v0.3.0 // indirect + github.com/spf13/afero v1.11.0 // indirect + github.com/spf13/cast v1.6.0 // indirect + github.com/spf13/pflag v1.0.5 // indirect + github.com/spf13/viper v1.19.0 // indirect + github.com/subosito/gotenv v1.6.0 // indirect + go.uber.org/atomic v1.9.0 // indirect + go.uber.org/multierr v1.9.0 // indirect + golang.org/x/exp v0.0.0-20230905200255-921286631fa9 // indirect + golang.org/x/sys v0.18.0 // indirect + golang.org/x/text v0.14.0 // indirect + gopkg.in/ini.v1 v1.67.0 // indirect + gopkg.in/yaml.v3 v3.0.1 // indirect +) diff --git a/go.sum b/go.sum new file mode 100644 index 0000000..02e8569 --- /dev/null +++ b/go.sum @@ -0,0 +1,68 @@ +github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc= +github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA= +github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM= +github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA= +github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4= +github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ= +github.com/magiconair/properties v1.8.7 h1:IeQXZAiQcpL9mgcAe1Nu6cX9LLw6ExEHKjN0VQdvPDY= +github.com/magiconair/properties v1.8.7/go.mod h1:Dhd985XPs7jluiymwWYZ0G4Z61jb3vdS329zhj2hYo0= +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-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM= +github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA= +github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y= +github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY= +github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo= +github.com/pelletier/go-toml/v2 v2.2.2 h1:aYUidT7k73Pcl9nb2gScu7NSrKCSHIDE89b3+6Wq+LM= +github.com/pelletier/go-toml/v2 v2.2.2/go.mod h1:1t835xjRzz80PqgE6HHgN2JOsmgYu/h4qDAS4n929Rs= +github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0= +github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4= +github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg= +github.com/rs/zerolog v1.33.0 h1:1cU2KZkvPxNyfgEmhHAz/1A9Bz+llsdYzklWFzgp0r8= +github.com/rs/zerolog v1.33.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss= +github.com/sagikazarmark/locafero v0.4.0 h1:HApY1R9zGo4DBgr7dqsTH/JJxLTTsOt7u6keLGt6kNQ= +github.com/sagikazarmark/locafero v0.4.0/go.mod h1:Pe1W6UlPYUk/+wc/6KFhbORCfqzgYEpgQ3O5fPuL3H4= +github.com/sagikazarmark/slog-shim v0.1.0 h1:diDBnUNK9N/354PgrxMywXnAwEr1QZcOr6gto+ugjYE= +github.com/sagikazarmark/slog-shim v0.1.0/go.mod h1:SrcSrq8aKtyuqEI1uvTDTK1arOWRIczQRv+GVI1AkeQ= +github.com/sourcegraph/conc v0.3.0 h1:OQTbbt6P72L20UqAkXXuLOj79LfEanQ+YQFNpLA9ySo= +github.com/sourcegraph/conc v0.3.0/go.mod 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v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA= +github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI= +github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg= +github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU= +github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo= +github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY= +github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8= +github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU= +go.uber.org/atomic v1.9.0 h1:ECmE8Bn/WFTYwEW/bpKD3M8VtR/zQVbavAoalC1PYyE= +go.uber.org/atomic v1.9.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc= +go.uber.org/multierr v1.9.0 h1:7fIwc/ZtS0q++VgcfqFDxSBZVv/Xo49/SYnDFupUwlI= +go.uber.org/multierr v1.9.0/go.mod h1:X2jQV1h+kxSjClGpnseKVIxpmcjrj7MNnI0bnlfKTVQ= +golang.org/x/exp v0.0.0-20230905200255-921286631fa9 h1:GoHiUyI/Tp2nVkLI2mCxVkOjsbSXD66ic0XW0js0R9g= +golang.org/x/exp v0.0.0-20230905200255-921286631fa9/go.mod h1:S2oDrQGGwySpoQPVqRShND87VCbxmc6bL1Yd2oYrm6k= +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= +golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4= +golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA= +golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ= +golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU= +gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0= +gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA= +gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k= +gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= +gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA= +gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= diff --git a/logging/logging.go b/logging/logging.go new file mode 100644 index 0000000..a24e13e --- /dev/null +++ b/logging/logging.go @@ -0,0 +1,43 @@ +package logging + +import ( + "encoding/json" + "fmt" + "io" + "os" + "time" + + "github.com/rs/zerolog" + + "www.thenautilus.net/cgit/go-example/config" +) + +// Logger returns a (optionally verbose) logger. +func Logger(conf config.LoggerConfig) zerolog.Logger { + logLevel := zerolog.InfoLevel + if conf.Verbose { + logLevel = zerolog.DebugLevel + } + + zerolog.TimestampFunc = func() time.Time { + return time.Now().UTC() + } + + zerolog.InterfaceMarshalFunc = func(value interface{}) ([]byte, error) { + switch v := value.(type) { + case fmt.Stringer: + str := fmt.Sprintf("\"%s\"", v.String()) + + return []byte(str), nil + default: + return json.Marshal(value) + } + } + + var w io.Writer = os.Stdout + if conf.Format == "console" { + w = zerolog.NewConsoleWriter() + } + + return zerolog.New(w).Level(logLevel).With().Timestamp().Logger() +} diff --git a/something/something.go b/something/something.go new file mode 100644 index 0000000..2516b2d --- /dev/null +++ b/something/something.go @@ -0,0 +1,23 @@ +package something + +import ( + "fmt" + + "www.thenautilus.net/cgit/go-example/config" +) + +type Something struct { + value int +} + +func New(conf *config.SomethingConfig) Something { + return Something{ + value: conf.Value, + } +} + +func (s *Something) DoSomething() error { + fmt.Printf("the value is %d", s.value) + + return nil +} -- cgit v1.2.3