Add the golang example code

golang/.gitignore

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+.DS_Store
+.idea
+go-bonsai
+*.iml

golang/README.md

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+## Go Bonsai! A lightweight Elasticsearch cluster exploration tool written in golang.
+
+To get started, clone the repo:
+
+```
+git clone [email protected]:omc/dogfood-go.git
+```
+
+Make sure to export your Bonsai cluster URL to the dev environment:
+
+```
+export BONSAI_URL="https://user:[email protected]"
+```
+
+Build the tool:
+
+```
+go build bonsai-example-go.go
+```
+
+Run it:
+
+```
+$ chmod +x go-bonsai
+$ ./go-bonsai
+```
+
+Check it out by opening up a browser and navigating to http://localhost:8080

golang/go-bonsai.go

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+package main
+
+import(
+	"./lib/controllers"
+	"net/http"
+)
+
+func main() {
+	http.HandleFunc("/", rootHandler)
+	http.HandleFunc("/index/", indexHandler)
+	http.ListenAndServe(":8080", nil)
+}
+
+func indexHandler(w http.ResponseWriter, r *http.Request) {
+	controllers.IndexBuilder(w, r)
+}
+
+func rootHandler(w http.ResponseWriter, r *http.Request) {
+	controllers.RootBuilder(w, r)
+}

golang/lib/controllers/http_handlers.go

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+package controllers
+
+import(
+	"../elasticsearch"
+	"../views"
+	"../errors"
+	"gopkg.in/olivere/elastic.v2"
+	"net/http"
+	"sort"
+)
+
+func IndexBuilder(w http.ResponseWriter, r *http.Request) {
+	es,index := elasticsearch.ConfirmIndex(w, r)
+	if index != "" {
+
+		// Get a list of sorted index names
+		indices, _ := es.IndexNames()
+		sort.Strings(indices)
+
+		// Query for some docs
+		// Use default settings for FROM and SIZE
+		query := elastic.NewQueryStringQuery("*")
+		docs,_ := es.Search().From(0).Size(10).Index(index).Query(query).Pretty(true).Do()
+
+		// Get a mapping for the index
+		mappings := elasticsearch.GetIndexMappings(es, index)
+		var mappingTypes []string
+		typeCounts := make(map[string]int64)
+		if docs.TotalHits() > 0 {
+			// No docs? Then there ain't no mappin' to get
+			types := mappings[index].(map[string]interface{})["mappings"].(map[string]interface{})
+			mappingTypes = elasticsearch.GetTypesFromMapping(types)
+			sort.Strings(mappingTypes)
+
+			for _,i:=range mappingTypes {
+				typeDocs,_ := es.Search().From(0).Size(10).Index(index).Type(i).Query(query).Pretty(true).Do()
+				typeCounts[i] = typeDocs.TotalHits()
+			}
+		}
+
+		//Create a view with the data and render it for the user
+		p := &views.View{
+			Title:        "Overview of " + index,
+			Hits:         docs.TotalHits(),
+			Docs:         docs.Hits.Hits,
+			Name:         index,
+			IndexCount:   len(indices),
+			Indices:      indices,
+			Mappings:     mappings,
+			MappingTypes: mappingTypes,
+			TypeCounts:   typeCounts}
+		views.Render(p, w, r, "index")
+	}
+}
+
+func RootBuilder(w http.ResponseWriter, r *http.Request) {
+	es := elasticsearch.GetClient()
+	indices,err := es.IndexNames()
+
+	if err != nil {
+		errors.ExitOnError(err, errors.INDEX_NAME_ERROR)
+	}
+	sort.Strings(indices)
+	health := elasticsearch.GetClusterHealth(es)
+	stats  := elasticsearch.GetClusterStats(es)
+	p := &views.View{
+		Title:      "Cluster Overview",
+		Health:      health,
+		Stats:       stats,
+		IndexCount:  len(indices),
+		Indices:     indices}
+	views.Render(p, w, r, "root")
+}

golang/lib/elasticsearch/elasticsearch.go

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+package elasticsearch
+
+import(
+	"gopkg.in/olivere/elastic.v2"
+	"os"
+	"regexp"
+	"strings"
+	"net/http"
+	"fmt"
+	"../errors"
+	"../views"
+)
+
+// Instantiate an Elasticsearch client
+func GetClient() *elastic.Client {
+	user,pass,host := parseBonsaiURL()
+	client, err := elastic.NewSimpleClient(
+		elastic.SetURL(host),
+		elastic.SetMaxRetries(10),
+		elastic.SetBasicAuth(user,pass),
+		elastic.SetSniff(false))
+	if err != nil {
+		errors.ExitOnError(err, errors.CLIENT_FAILURE)
+	}
+	return client
+}
+
+//
+func GetClusterHealth(es *elastic.Client) *elastic.ClusterHealthResponse {
+	health,_ := 	es.ClusterHealth().
+			Do()
+	return health
+}
+
+//
+func GetClusterStats(es *elastic.Client) *elastic.IndicesStatsResponse {
+	stats,_ := 	es.IndexStats().
+			   Index("_all").
+			   Human(true).
+			   Pretty(true).
+			   Do()
+	return stats
+}
+
+func SearchDocuments(es *elastic.Client, index string) *elastic.SearchResult {
+	docs,_ :=    es.Search().
+			Index(index).
+			Do()
+	return docs
+}
+
+func GetIndexMappings(es *elastic.Client, index string) map[string]interface{} {
+	mappings,err := es.GetMapping().Index(index).Do()
+	if err != nil {
+		errors.ExitOnError(err, errors.INDEX_MAPPING_ERROR)
+	}
+	return mappings
+}
+
+// Make sure that an index exists before we do anything with it.
+// If it exists, return the client for reuse
+func ConfirmIndex(w http.ResponseWriter, r *http.Request) (*elastic.Client, string) {
+	rex, err := regexp.Compile("/index/(.*?)")
+	index := rex.ReplaceAllString(r.URL.Path, "$1")
+	if err != nil {
+		errors.ExitOnError(err, errors.REGEX_COMPILE)
+	}
+	es := GetClient()
+	indexCheck, err := es.IndexExists(index).Do()
+	if indexCheck == false {
+		indices,_ := es.IndexNames()
+		fmt.Printf("Aw, brah, I couldn't find an index called '%s'!\n", index)
+		p := &views.View{IndexCount: len(indices), Indices: indices, ErrorMessage: "That index doesn't exist!"}
+		views.Render(p, w, r, "root")
+		return es,""
+	} else if err != nil {
+		errors.ExitOnError(err, errors.INDEX_EXISTS_ERROR)
+	}
+	return es, index
+}
+
+func parseBonsaiURL() (string, string, string){
+	url := os.Getenv("BONSAI_URL")
+	rex, _ := regexp.Compile(".*?://([a-z0-9]{1,}):([a-z0-9]{1,})@.*$")
+	user := rex.ReplaceAllString(url, "$1")
+	pass := rex.ReplaceAllString(url, "$2")
+	host := strings.Replace(url, user+":"+pass+"@", "", -1)
+	return user,pass,host
+}
+
+func GetTypesFromMapping(m map[string]interface{}) (types []string) {
+	for k := range m {
+		types = append(types, k)
+	}
+	return types
+}
+

golang/lib/errors/errors.go

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+package errors
+
+import (
+	"fmt"
+	"os"
+)
+
+const (
+	CLIENT_FAILURE     = "Could not instantiate a client to the Elasticsearch cluster"
+	JSON_DECODE_FAILURE = "Could not decode JSON"
+	INDEX_EXISTS_ERROR = "The Elasticsearch client failed to determine whether the index exists"
+	INDEX_NAME_ERROR   = "An error occurred while retrieving the cluster's index names"
+	REGEX_COMPILE      = "Could not compile the regular expression"
+	TEMPLATE_PARSE_FAILURE   = "The template engine failed to parse the requested view"
+	TEMPLATE_EXECUTE_FAILURE = "The template engine failed to execute the requested view"
+	INDEX_MAPPING_ERROR = "The requested index mapping could not be found"
+)
+
+// Quit the program if there is an error
+func ExitOnError(err error, errMsg string) {
+	fmt.Printf("The program exited with error category '%s'. Specific failure: %s\n", errMsg, err)
+	os.Exit(1)
+}

golang/lib/views/templates/container.tmpl

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+{{define "container"}}
+    <div class="container-fluid">
+      <div class="row">
+        <div class="col-sm-3 col-md-2 sidebar">
+            {{ template "sidebar" . }}
+        </div>
+        <div class="col-sm-9 col-sm-offset-3 col-md-10 col-md-offset-2 main">
+
+          {{if .ErrorMessage}}
+          <div class="alert alert-danger">
+            {{ .ErrorMessage }}
+          </div>
+          {{end}}
+
+          {{ template "content" . }}
+
+        </div>
+      </div>
+    </div>
+{{end}}

golang/lib/views/templates/footer.tmpl

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+{{define "footer"}}
+    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
+    <script src="http://getbootstrap.com/dist/js/bootstrap.min.js"></script>
+{{end}}

golang/lib/views/templates/header.tmpl

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+{{define "header"}}
+    <meta charset=utf-8>
+    <meta http-equiv=X-UA-Compatible content="IE=edge">
+    <meta name=viewport content="width=device-width,initial-scale=1">
+    <meta name=author content="Rob Sears">
+    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
+    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap-theme.min.css">
+    <link rel="stylesheet" href="http://getbootstrap.com/examples/dashboard/dashboard.css">
+    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css">
+    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
+    <script src="//d3js.org/d3.v3.min.js" charset="utf-8"></script>
+    <title>{{ .Title }}</title>
+{{end}}

golang/lib/views/templates/index.tmpl

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+{{ define "content"}}
+<h1 class="page-header">Overview of {{ .Name }}</h1>
+
+    {{if gt .Hits 0}}
+
+    <div>
+
+      <!-- Nav tabs -->
+      <ul class="nav nav-tabs" role="tablist">
+        <li role="presentation" class="active"><a href="#home" aria-controls="home" role="tab" data-toggle="tab">Stats</a></li>
+        <li role="presentation"><a href="#profile" aria-controls="profile" role="tab" data-toggle="tab">Fields</a></li>
+        <li role="presentation"><a href="#messages" aria-controls="messages" role="tab" data-toggle="tab">Documents</a></li>
+      </ul>
+
+      <!-- Tab panes -->
+      <div class="tab-content">
+        <div role="tabpanel" class="tab-pane active" id="home">
+            <style>
+
+            .chart div {
+              font: 10px sans-serif;
+              background-color: steelblue;
+              text-align: right;
+              padding: 3px;
+              margin: 1px;
+              color: white;
+              min-width:100px;
+            }
+
+            </style>
+            <div class="chart"></div>
+            <script language="javascript" type="text/javascript">
+                var data = {{ d3data .TypeCounts }};
+                var keys = Object.keys(data)
+                var vals = Object.keys(data).map(function(v) { return (((data[v]) * 100.0 / {{ .Hits }}).toFixed(0)); })
+                var x = d3.scale.linear()
+                    .domain([0, d3.max(vals)])
+                    .range([0, 100]);
+
+                d3.select(".chart")
+                  .selectAll("div")
+                    .data(vals)
+                  .enter().append("div")
+                    .style("width", function(d) { return x(d) + "%"; })
+                    .text(function(d) { return keys.shift() + ": " + vals.shift() + "%"; });
+            </script>
+        </div>
+        <div role="tabpanel" class="tab-pane" id="profile">
+            <div class="table-responsive">
+                <table  class="table table-striped">
+                    <thead>
+                        <th>Type</th>
+                        <th>Fields</th>
+                    </thead>
+                    <tbody>
+                    {{range $type := .MappingTypes}}
+                        <tr>
+                            <td>{{ $type }}</td>
+                            <td>
+                                <ul>
+                                {{ range $field := mappingFields $.Mappings $.Name $type}}
+                                    <li>{{ $field }}</li>
+                                {{ end }}
+                                </ul>
+                            </td>
+                        </tr>
+                    {{ end }}
+                    </tbody>
+                </table>
+            </div>
+        </div>
+        <div role="tabpanel" class="tab-pane" id="messages">
+            <div class="table-responsive">
+                <table  class="table table-striped">
+                    <thead>
+                        <th>ID</th>
+                        <th>Type</th>
+                        <th>Source</th>
+                    </thead>
+                    <tbody>
+                    {{range $doc := .Docs}}
+                        <tr>
+                            <td>{{ $doc.Id }}</td>
+                            <td>{{ $doc.Type }}</td>
+                            <td>
+                                {{ jsonDecode $doc }}
+                            </td>
+                        </tr>
+                    {{ end }}
+                    </tbody>
+                </table>
+            </div>
+        </div>
+      </div>
+
+    </div>
+    {{end}}
+
+{{ end }}