main.go

// Copyright (c) 2018 Ashley Jeffs
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package main

import (
	"bytes"
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	"path/filepath"
	"sort"
	"strings"

	"github.com/Jeffail/benthos/lib/api"
	"github.com/Jeffail/benthos/lib/buffer"
	"github.com/Jeffail/benthos/lib/input"
	"github.com/Jeffail/benthos/lib/log"
	"github.com/Jeffail/benthos/lib/manager"
	"github.com/Jeffail/benthos/lib/metrics"
	"github.com/Jeffail/benthos/lib/output"
	"github.com/Jeffail/benthos/lib/pipeline"
	"github.com/Jeffail/benthos/lib/processor"
	"github.com/Jeffail/benthos/lib/processor/condition"
	yaml "gopkg.in/yaml.v2"
)

//------------------------------------------------------------------------------

// Config is the benthos configuration struct.
type Config struct {
	HTTP     api.Config      `json:"http" yaml:"http"`
	Input    input.Config    `json:"input" yaml:"input"`
	Buffer   buffer.Config   `json:"buffer" yaml:"buffer"`
	Pipeline pipeline.Config `json:"pipeline" yaml:"pipeline"`
	Output   output.Config   `json:"output" yaml:"output"`
	Manager  manager.Config  `json:"resources" yaml:"resources"`
	Logger   log.Config      `json:"logger" yaml:"logger"`
	Metrics  metrics.Config  `json:"metrics" yaml:"metrics"`
}

// NewConfig returns a new configuration with default values.
func NewConfig() Config {
	return Config{
		HTTP:     api.NewConfig(),
		Input:    input.NewConfig(),
		Buffer:   buffer.NewConfig(),
		Pipeline: pipeline.NewConfig(),
		Output:   output.NewConfig(),
		Manager:  manager.NewConfig(),
		Logger:   log.NewConfig(),
		Metrics:  metrics.NewConfig(),
	}
}

// Sanitised returns a sanitised copy of the Benthos configuration, meaning
// fields of no consequence (unused inputs, outputs, processors etc) are
// excluded.
func (c Config) Sanitised(sanitBuffer, sanitPipe bool) (interface{}, error) {
	inConf, err := input.SanitiseConfig(c.Input)
	if err != nil {
		return nil, err
	}

	var bufConf interface{}
	if sanitBuffer {
		bufConf, err = buffer.SanitiseConfig(c.Buffer)
		if err != nil {
			return nil, err
		}
	} else {
		bufConf = c.Buffer
	}

	var pipeConf interface{}
	if sanitPipe {
		pipeConf, err = pipeline.SanitiseConfig(c.Pipeline)
		if err != nil {
			return nil, err
		}
	} else {
		pipeConf = c.Pipeline
	}

	var outConf interface{}
	outConf, err = output.SanitiseConfig(c.Output)
	if err != nil {
		return nil, err
	}

	var mgrConf interface{}
	mgrConf, err = manager.SanitiseConfig(c.Manager)
	if err != nil {
		return nil, err
	}

	return struct {
		HTTP     interface{} `json:"http" yaml:"http"`
		Input    interface{} `json:"input" yaml:"input"`
		Buffer   interface{} `json:"buffer" yaml:"buffer"`
		Pipeline interface{} `json:"pipeline" yaml:"pipeline"`
		Output   interface{} `json:"output" yaml:"output"`
		Manager  interface{} `json:"resources" yaml:"resources"`
		Logger   interface{} `json:"logger" yaml:"logger"`
		Metrics  interface{} `json:"metrics" yaml:"metrics"`
	}{
		HTTP:     c.HTTP,
		Input:    inConf,
		Buffer:   bufConf,
		Pipeline: pipeConf,
		Output:   outConf,
		Manager:  mgrConf,
		Logger:   c.Logger,
		Metrics:  c.Metrics,
	}, nil
}

//------------------------------------------------------------------------------

func create(t, path string, resBytes []byte) {
	if err := ioutil.WriteFile(path, resBytes, 0644); err != nil {
		panic(err)
	}
	fmt.Printf("Generated '%v' at: %v\n", t, path)
}

func createYAML(t, path string, sanit interface{}) {
	resBytes := []byte("# This file was auto generated by benthos_config_gen.\n")

	cBytes, err := yaml.Marshal(sanit)
	if err != nil {
		panic(err)
	}
	resBytes = append(resBytes, cBytes...)

	if err = ioutil.WriteFile(path, resBytes, 0644); err != nil {
		panic(err)
	}
	fmt.Printf("Generated '%v' config at: %v\n", t, path)
}

func createJSON(t, path string, sanit interface{}) {
	resBytes, err := json.MarshalIndent(sanit, "", "	")
	if err != nil {
		panic(err)
	}

	if err = ioutil.WriteFile(path, resBytes, 0644); err != nil {
		panic(err)
	}
	fmt.Printf("Generated '%v' config at: %v\n", t, path)
}

func envify(rootPath string, conf interface{}, paths map[string]string) (newConf interface{}) {
	genBytes, err := json.Marshal(conf)
	if err != nil {
		panic(err)
	}

	dec := json.NewDecoder(bytes.NewReader(genBytes))
	dec.UseNumber()

	var genConf interface{}
	if err = dec.Decode(&genConf); err != nil {
		panic(err)
	}

	staticlist := []string{
		"INPUT_TYPE",
		"OUTPUT_TYPE",
	}
	blacklist := []string{
		"READ_UNTIL",
		"OUTPUT_BROKER_OUTPUTS_RETRY",
		"CONDITIONAL",
		"PROCESS_FIELD",
		"PROCESS_MAP",
		"CHECK_FIELD",
		"FILTER",
		"DEDUPE",
		"INPUT_BROKER_INPUTS_BROKER",
		"OUTPUT_BROKER_OUTPUTS_BROKER",
		"OUTPUT_BROKER_OUTPUTS_DYNAMODB",
		"LOGGER_STATIC_FIELDS",
	}
	aliases := map[string]string{
		"INPUT_BROKER_INPUTS":   "INPUT",
		"INPUT_BROKER_COPIES":   "INPUTS",
		"PIPELINE_PROCESSORS":   "PROCESSOR",
		"PIPELINE_THREADS":      "PROCESSOR_THREADS",
		"OUTPUT_BROKER_OUTPUTS": "OUTPUT",
		"OUTPUT_BROKER_PATTERN": "OUTPUTS_PATTERN",
		"OUTPUT_BROKER_COPIES":  "OUTPUTS",
	}

	var traverse func(path string, to *interface{}, from interface{})
	traverse = func(path string, to *interface{}, from interface{}) {
		if obj, isObj := from.(map[string]interface{}); isObj {
			newMap := map[string]interface{}{}
		keyIter:
			for k, v := range obj {
				newPath := path + "_" + strings.Replace(strings.ToUpper(k), "-", "_", -1)
				for _, b := range staticlist {
					if strings.Contains(newPath, b) {
						// Preserve values that hit our staticlist.
						newMap[k] = v
						continue keyIter
					}
				}
				for _, b := range blacklist {
					if strings.Contains(newPath, b) {
						// Skip values that hit our blacklist.
						continue keyIter
					}
				}
				var newVal interface{}
				traverse(newPath, &newVal, v)
				if newVal != nil {
					newMap[k] = newVal
				}
			}
			if len(newMap) > 0 {
				*to = newMap
			}
			return
		} else if len(path) == 0 {
			panic("Environment values at path root")
		}
		if array, isArray := from.([]interface{}); isArray {
			var newArray []interface{}
			for _, ele := range array {
				var newVal interface{}
				traverse(path, &newVal, ele)
				if newVal != nil {
					newArray = append(newArray, newVal)
				}
			}
			if len(newArray) > 0 {
				*to = newArray
			}
			return
		}
		for alias := range aliases {
			if strings.Contains(path, alias) {
				path = strings.Replace(path, alias, aliases[alias], 1)
			}
		}
		var valStr string
		switch t := from.(type) {
		case string:
			valStr = t
		case bool:
			if t {
				valStr = "true"
			} else {
				valStr = "false"
			}
		case json.Number:
			valStr = t.String()
		}
		paths[path] = valStr
		if len(valStr) > 0 {
			*to = "${" + path + ":" + valStr + "}"
		} else {
			*to = "${" + path + "}"
		}
	}

	traverse(rootPath, &newConf, genConf)
	return
}

func formatEnvVars(vars map[string]string) []byte {
	categories := []string{
		"HTTP", "INPUT", "BUFFER", "PROCESSOR", "OUTPUT", "LOGGER", "METRICS",
	}
	priorityVars := []string{
		"INPUTS", "PROCESSOR_THREADS", "OUTPUTS", "OUTPUTS_PATTERN",
		"INPUT_TYPE", "BUFFER_TYPE", "PROCESSOR_TYPE",
		"OUTPUT_TYPE", "METRICS_TYPE",
	}

	sortedVars := []string{}
	for k := range vars {
		sortedVars = append(sortedVars, k)
	}
	sort.Strings(sortedVars)

	var buf bytes.Buffer

	buf.WriteString(`Environment Config
==================

This document was auto generated by ` + "`benthos_config_gen`" + `.

The environment variables config ` + "[`default.yaml`](default.yaml)" + ` is an
auto generated Benthos configuration where _all_ fields can be set with
environment variables. The architecture of the config is a standard bridge
between N replicated sources, M replicated sinks and an optional buffer and
processing pipeline between them.

The original intent of this config is to be deployed within a docker image, but
as it is a standard config it can be used in other deployments.

In order to use this config simply define your env vars and point Benthos to it.
For example, to send Kafka data to RabbitMQ you can run:

` + "``` sh" + `
INPUT_TYPE=kafka_balanced \
  INPUT_KAFKA_ADDRESSES=localhost:9092 \
  INPUT_KAFKA_TOPIC=foo-topic \
  INPUT_KAFKA_CONSUMER_GROUP=foo-consumer \
  OUTPUT_TYPE=amqp \
  OUTPUT_AMQP_URL=amqp://guest:guest@localhost:5672/ \
  OUTPUT_AMQP_EXCHANGE=foo-exchange \
  OUTPUT_AMQP_EXCHANGE_TYPE=direct \
  benthos -c ./config/env/default.yaml
` + "```" + `

All variables within the config are listed in this document.

## Contents
`)

	for _, section := range categories {
		buf.WriteByte('\n')
		buf.WriteString("- [" + section + "](#" + strings.ToLower(section) + ")")
	}
	buf.WriteByte('\n')

	for _, section := range categories {
		buf.WriteString("\n")
		buf.WriteString("## " + section)
		buf.WriteString("\n\n```\n")

		catVars := []string{}

		for _, v := range priorityVars {
			if !strings.HasPrefix(v, section) {
				continue
			}
			catVars = append(catVars, v)
		}
	sortedIter:
		for _, v := range sortedVars {
			if !strings.HasPrefix(v, section) {
				continue
			}
			for _, v2 := range priorityVars {
				if v == v2 {
					continue sortedIter
				}
			}
			catVars = append(catVars, v)
		}

		vMaxLen := 0
		for _, v := range catVars {
			if len(v) > vMaxLen {
				vMaxLen = len(v)
			}
		}
		for _, v := range catVars {
			buf.WriteString(v)
			if defVal := vars[v]; len(defVal) > 0 {
				for i := len(v); i < vMaxLen; i++ {
					buf.WriteByte(' ')
				}
				buf.WriteString(" = " + defVal)
			}
			buf.WriteByte('\n')
		}
		buf.WriteString("```\n")
	}

	return buf.Bytes()
}

func createEnvConf(configsDir string) {
	inConf := input.NewConfig()
	inConf.Type = "dynamic"

	inBrokerConf := struct {
		Copies int           `json:"copies"`
		Inputs []interface{} `json:"inputs"`
	}{
		Copies: 1,
		Inputs: []interface{}{inConf},
	}

	procConf := processor.NewConfig()
	procConf.Type = "noop"

	pipeConf := pipeline.NewConfig()
	pipeConf.Processors = append(pipeConf.Processors, procConf)

	outConf := output.NewConfig()
	outConf.Type = "dynamic"

	outBrokerConf := struct {
		Copies  int           `json:"copies"`
		Pattern string        `json:"pattern"`
		Outputs []interface{} `json:"outputs"`
	}{
		Copies:  1,
		Pattern: "greedy",
		Outputs: []interface{}{outConf},
	}

	conf := NewConfig()

	envConf := struct {
		HTTP     interface{} `json:"http"`
		Input    interface{} `json:"input"`
		Buffer   interface{} `json:"buffer"`
		Pipeline interface{} `json:"pipeline"`
		Output   interface{} `json:"output"`
		Logger   interface{} `json:"logger"`
		Metrics  interface{} `json:"metrics"`
	}{
		HTTP: conf.HTTP,
		Input: struct {
			Type   string      `json:"type"`
			Broker interface{} `json:"broker"`
		}{
			Type:   "broker",
			Broker: inBrokerConf,
		},
		Buffer:   conf.Buffer,
		Pipeline: pipeConf,
		Output: struct {
			Type   string      `json:"type"`
			Broker interface{} `json:"broker"`
		}{
			Type:   "broker",
			Broker: outBrokerConf,
		},
		Logger:  log.NewConfig(),
		Metrics: metrics.NewConfig(),
	}

	pathsMap := map[string]string{}
	envConf.HTTP = envify("HTTP", envConf.HTTP, pathsMap)
	envConf.Input = envify("INPUT", envConf.Input, pathsMap)
	envConf.Buffer = envify("BUFFER", envConf.Buffer, pathsMap)
	envConf.Pipeline = envify("PIPELINE", envConf.Pipeline, pathsMap)
	envConf.Output = envify("OUTPUT", envConf.Output, pathsMap)
	envConf.Logger = envify("LOGGER", envConf.Logger, pathsMap)
	envConf.Metrics = envify("METRICS", envConf.Metrics, pathsMap)

	createYAML("environment file", filepath.Join(configsDir, "env", "default.yaml"), envConf)
	create("environment file docs", filepath.Join(configsDir, "env", "README.md"), formatEnvVars(pathsMap))
}

func main() {
	configsDir := "./config"
	flag.StringVar(&configsDir, "dir", configsDir, "The directory to write config examples")
	flag.Parse()

	// Get list of all types (both input and output).
	typeMap := map[string]struct{}{}
	for t := range input.Constructors {
		typeMap[t] = struct{}{}
	}
	for t := range output.Constructors {
		typeMap[t] = struct{}{}
	}

	// Generate configs for all types.
	for t := range typeMap {
		conf := NewConfig()
		conf.Input.Processors = nil
		conf.Output.Processors = nil
		conf.Pipeline.Processors = nil

		if _, exists := input.Constructors[t]; exists {
			conf.Input.Type = t
		}
		if _, exists := output.Constructors[t]; exists {
			conf.Output.Type = t
		}

		sanit, err := conf.Sanitised(true, true)
		if err != nil {
			panic(err)
		}

		createYAML(t, filepath.Join(configsDir, t+".yaml"), sanit)
		createJSON(t, filepath.Join(configsDir, t+".json"), sanit)
	}

	// Create processor configs for all types.
	for t := range processor.Constructors {
		conf := NewConfig()
		conf.Input.Processors = nil
		conf.Output.Processors = nil

		procConf := processor.NewConfig()
		procConf.Type = t

		conf.Pipeline.Processors = append(conf.Pipeline.Processors, procConf)

		sanit, err := conf.Sanitised(true, true)
		if err != nil {
			panic(err)
		}

		createYAML(t, filepath.Join(configsDir, "processors", t+".yaml"), sanit)
		createJSON(t, filepath.Join(configsDir, "processors", t+".json"), sanit)
	}

	// Create condition configs for all types.
	for t := range condition.Constructors {
		conf := NewConfig()
		conf.Input.Processors = nil
		conf.Output.Processors = nil

		condConf := condition.NewConfig()
		condConf.Type = t

		procConf := processor.NewConfig()
		procConf.Type = "filter_parts"
		procConf.FilterParts = processor.FilterPartsConfig{
			Config: condConf,
		}

		conf.Pipeline.Processors = append(conf.Pipeline.Processors, procConf)

		sanit, err := conf.Sanitised(true, true)
		if err != nil {
			panic(err)
		}

		createYAML(t, filepath.Join(configsDir, "conditions", t+".yaml"), sanit)
		createJSON(t, filepath.Join(configsDir, "conditions", t+".json"), sanit)
	}

	// Create buffers config
	{
		t := "buffers"

		conf := NewConfig()
		conf.Input.Processors = nil
		conf.Output.Processors = nil

		sanit, err := conf.Sanitised(false, true)
		if err != nil {
			panic(err)
		}

		createYAML(t, filepath.Join(configsDir, t+".yaml"), sanit)
		createJSON(t, filepath.Join(configsDir, t+".json"), sanit)
	}

	// Create Environment Vars Config
	createEnvConf(configsDir)
}

//------------------------------------------------------------------------------