cait-servepages.go

//
// This is a static file web server and search service.
// for interacting with ArchivesSpace's REST API
//
// @author R. S. Doiel, <rsdoiel@caltech.edu>
//
// Copyright (c) 2017, Caltech
// All rights not granted herein are expressly reserved by Caltech.
//
// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
package main

import (
	"bytes"
	"crypto/hmac"
	"crypto/sha1"
	"encoding/hex"
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"net/url"
	"os"
	"os/exec"
	"os/signal"
	"path"
	"path/filepath"
	"strconv"
	"strings"
	"syscall"
	"text/template"

	// Caltech Library packages
	"github.com/caltechlibrary/cait"
	"github.com/caltechlibrary/cli"
	"github.com/caltechlibrary/tmplfn"

	// BleveSearch Packages (3rd Party packages)
	"github.com/blevesearch/bleve"
	"github.com/blevesearch/bleve/search/query"
)

var (
	usage = `USAGE: %s [OPTIONS]`

	description = `
 OVERVIEW

%s provides search services defined by CAIT_SITE_URL for the
website content defined by CAIT_HTDOCS using the index defined
by CAIT_BLEVE. Additionally a webhook call can be defined
to trigger an action such as pulling new site content.

CONFIGURATION

%s can be configured through environment variables. The following
variables are supported-

   CAIT_SITE_URL

   CAIT_HTDOCS

   CAIT_BLEVE

   CAIT_TEMPLATES

   CAIT_WEBHOOK_PATH
   
   CAIT_WEBHOOK_SECRET
   
   CAIT_WEBHOOK_COMMAND

`

	showHelp    bool
	showVersion bool
	showLicense bool

	bleveNames     string //NOTE: This is a colon delimited string of swapable indexes
	htdocsDir      string
	templatesDir   string
	siteURL        string
	webhookPath    string
	webhookSecret  string
	webhookCommand string
	enableSearch   bool

	advancedPage []byte
	basicPage    []byte

	indexAlias bleve.IndexAlias
	index      bleve.Index

	// Internal package var
	tmplFuncs = tmplfn.Join(tmplfn.TimeMap, tmplfn.PageMap, cait.TmplMap)
)

func mapToSearchQuery(m map[string]interface{}) (*cait.SearchQuery, error) {
	var err error

	// raw is a tempory data structure to sanitize the
	// form request submitted via the query.
	raw := &struct {
		Q         string `json:"q"`
		QExact    string `json:"q_exact"`
		QExcluded string `json:"q_excluded"`
		QRequired string `json:"q_required"`
		Size      int    `json:"size"`
		From      int    `json:"from"`
		AllIDs    bool   `json:"all_ids"`
	}{}

	isQuery := false

	q := new(cait.SearchQuery)
	src, err := json.Marshal(m)
	if err != nil {
		return nil, fmt.Errorf("Can't marshal %+v, %s", m, err)
	}
	err = json.Unmarshal(src, &raw)
	if err != nil {
		return nil, fmt.Errorf("Can't unmarshal %s, %s", src, err)
	}
	if len(raw.Q) > 0 {
		q.Q = raw.Q
		isQuery = true
	}
	if len(raw.QExact) > 0 {
		q.QExact = raw.QExact
		isQuery = true
	}
	if len(raw.QExcluded) > 0 {
		q.QExcluded = q.QExact
	}
	if len(raw.QRequired) > 0 {
		q.QRequired = raw.QRequired
		isQuery = true
	}

	if isQuery == false {
		return nil, fmt.Errorf("Missing query value fields")
	}

	if raw.AllIDs == true {
		q.AllIDs = true
	}

	//Note: if q.Size is not set by the query request pick a nice default value
	if raw.Size <= 1 {
		q.Size = 10
	} else {
		q.Size = raw.Size
	}
	if raw.From < 0 {
		q.From = 0
	} else {
		q.From = raw.From
	}
	return q, nil
}

func urlToRepoAccessionIDs(uri string) (int, int, error) {
	var err error
	repoID := 0
	accessionID := 0

	parts := strings.SplitN(uri, "/", 7)
	if len(parts) > 4 {
		repoID, err = strconv.Atoi(parts[4])
		if err != nil {
			return 0, 0, fmt.Errorf("Cannot parse repository id %s, %s", uri, err)
		}
	}
	if len(parts) >= 6 {
		id := filepath.Base(uri)
		accessionID, err = strconv.Atoi(id)
		if err != nil {
			return repoID, 0, fmt.Errorf("Cannot parse accession id %s, %s", uri, err)
		}
	}
	return repoID, accessionID, nil
}

func resultsHandler(w http.ResponseWriter, r *http.Request) {
	var (
		pageHTML    = "results-search.html"
		pageInclude = "results-search.include"
	)

	urlQuery := r.URL.Query()
	err := r.ParseForm()
	if err != nil {
		responseLogger(r, http.StatusBadRequest, err)
		w.Header().Set("Content-Type", "text/plain")
		w.WriteHeader(http.StatusBadRequest)
		w.Write([]byte(fmt.Sprintf("error in POST: %s", err)))
		return
	}

	// Collect the submissions fields.
	submission := make(map[string]interface{})
	// Basic Search results
	if r.Method == "GET" {
		for k, v := range urlQuery {
			if k == "all_ids" {
				if b, err := strconv.ParseBool(strings.Join(v, "")); err == nil {
					submission[k] = b
				}
			} else if k == "from" || k == "size" || k == "total" {
				if i, err := strconv.Atoi(strings.Join(v, "")); err == nil {
					submission[k] = i
				}
			} else if k == "q" || k == "q_exact" || k == "q_excluded" || k == "q_required" {
				submission[k] = strings.Join(v, "")
			}
		}
	}

	// Advanced Search results
	if r.Method == "POST" {
		for k, v := range r.Form {
			if k == "all_ids" {
				if b, err := strconv.ParseBool(strings.Join(v, "")); err == nil {
					submission[k] = b
				}
			} else if k == "from" || k == "size" || k == "total" {
				if i, err := strconv.Atoi(strings.Join(v, "")); err == nil {
					submission[k] = i
				}
			} else if k == "q" || k == "q_exact" || k == "q_excluded" || k == "q_required" {
				submission[k] = strings.Join(v, "")
			}
		}
	}

	q, err := mapToSearchQuery(submission)
	if err != nil {
		responseLogger(r, http.StatusBadRequest, err)
		w.WriteHeader(http.StatusBadRequest)
		w.Write([]byte(fmt.Sprintf("%s", err)))
		return
	}

	//
	// Note: Add logic to handle basic and advanced search...
	//
	// q           NewQueryStringQuery
	// q_required  NewQueryStringQuery with a + prefix for each strings.Fields(q_required) value
	// q_exact     NewMatchPhraseQuery
	// q_excluded NewQueryStringQuery with a - prefix for each strings.Feilds(q_excluded) value
	//
	var conQry []query.Query

	if q.Q != "" {
		conQry = append(conQry, bleve.NewQueryStringQuery(q.Q))
	}
	if q.QExact != "" {
		conQry = append(conQry, bleve.NewMatchPhraseQuery(q.QExact))
	}
	var terms []string
	for _, s := range strings.Fields(q.QRequired) {
		terms = append(terms, fmt.Sprintf("+%s", strings.TrimSpace(s)))
	}
	for _, s := range strings.Fields(q.QExcluded) {
		terms = append(terms, fmt.Sprintf("-%s", strings.TrimSpace(s)))
	}
	if len(terms) > 0 {
		qString := strings.Join(terms, " ")
		conQry = append(conQry, bleve.NewQueryStringQuery(qString))
	}

	qry := bleve.NewConjunctionQuery(conQry...)
	if q.Size == 0 {
		q.Size = 10
	}
	searchRequest := bleve.NewSearchRequestOptions(qry, q.Size, q.From, q.Explain)
	if searchRequest == nil {
		responseLogger(r, http.StatusBadRequest, fmt.Errorf("Can't build new search request options %+v, %s", qry, err))
		w.WriteHeader(http.StatusBadRequest)
		w.Write([]byte(fmt.Sprintf("%s", err)))
		return
	}

	searchRequest.Highlight = bleve.NewHighlight()
	searchRequest.Highlight.AddField("title")
	searchRequest.Highlight.AddField("content_description")
	searchRequest.Highlight.AddField("subjects")
	searchRequest.Highlight.AddField("subjects_function")
	searchRequest.Highlight.AddField("subjects_topical")
	searchRequest.Highlight.AddField("extents")

	subjectFacet := bleve.NewFacetRequest("subjects", 3)
	searchRequest.AddFacet("subjects", subjectFacet)

	subjectTopicalFacet := bleve.NewFacetRequest("subjects_topical", 3)
	searchRequest.AddFacet("subjects_topical", subjectTopicalFacet)

	subjectFunctionFacet := bleve.NewFacetRequest("subjects_function", 3)
	searchRequest.AddFacet("subjects_function", subjectFunctionFacet)

	// Return all fields
	searchRequest.Fields = []string{
		"title",
		"identifier",
		"content_description",
		"content_condition",
		"resource_type",
		"access_restrictions",
		"access_restrictions_note",
		"use_restrictins",
		"use_restrictons_note",
		"dates",
		"date_expression",
		"extents",
		"subjects",
		"subjects_function",
		"subjects_topical",
		"linked_agents_creators",
		"linked_agents_subjects",
		"link_agents_sources",
		"digital_objects.title",
		"digital_objects.file_uris",
		"related_resources",
		"deaccessions",
		"accession_date",
		"created",
	}

	searchResults, err := index.Search(searchRequest)
	if err != nil {
		responseLogger(r, http.StatusInternalServerError, fmt.Errorf("Bleve results error %v, %s", qry, err))
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte(fmt.Sprintf("%s", err)))
		return
	}

	// q (ciat.SearchQuery) performs double duty as both the structure for query submission as well
	// as carring the results to support paging and other types of navigation through
	// the query set. Results are a query with the bleve.SearchReults merged
	q.AttachSearchResults(searchResults)
	pageHTML = "results-search.html"
	pageInclude = "results-search.include"

	// Load my templates and setup to execute them
	tmpl, err := tmplfn.Assemble(tmplFuncs, path.Join(templatesDir, pageHTML), path.Join(templatesDir, pageInclude))
	if err != nil {
		responseLogger(r, http.StatusInternalServerError, fmt.Errorf("Template Errors: %s, %s, %s\n", pageHTML, pageInclude, err))
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte(fmt.Sprintf("Template errors: %s", err)))
		return
	}
	// Render the page
	w.Header().Set("Content-Type", "text/html")
	var buf bytes.Buffer
	err = tmpl.Execute(&buf, q)
	//err = tmpl.Execute(w, q)
	if err != nil {
		responseLogger(r, http.StatusInternalServerError, fmt.Errorf("Can't render %s, %s/%s, %s", templatesDir, pageHTML, pageInclude, err))
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("Template error"))
		return
	}
	//NOTE: This hack is a bit of ugliness is here because I need to allow <mark> elements and ellipis in the results fragments
	w.Write(bytes.Replace(bytes.Replace(bytes.Replace(bytes.Replace(bytes.Replace(buf.Bytes(), []byte("&lt;mark&gt;"), []byte("<mark>"), -1), []byte("&lt;/mark&gt;"), []byte("</mark>"), -1), []byte(`…`), []byte(`&hellip;`), -1), []byte(`”`), []byte(`&rdquo;`), -1), []byte(`’`), []byte(`&rsquo;`), -1))
}

func searchHandler(w http.ResponseWriter, r *http.Request) {
	//logRequest(r)
	// If GET with Query String or POST pass to results handler
	// else display Basic Search Form
	query := r.URL.Query()
	if r.Method == "POST" || len(query) > 0 {
		resultsHandler(w, r)
		return
	}

	// Shared form data fields for a New Search.
	formData := struct {
		URI string
	}{
		URI: "/",
	}

	// Handle the basic or advanced search form requests.
	var (
		tmpl *template.Template
		err  error
	)
	w.Header().Set("Content-Type", "text/html")
	if strings.HasPrefix(r.URL.Path, "/search/advanced") == true {
		formData.URI = "/search/advanced/"
		tmpl, err = tmplfn.Assemble(tmplFuncs, path.Join(templatesDir, "advanced-search.html"), path.Join(templatesDir, "advanced-search.include"))
		if err != nil {
			fmt.Printf("Can't read advanced-search templates, %s", err)
			return
		}
	} else {
		formData.URI = "/search/basic/"
		tmpl, err = tmplfn.Assemble(tmplFuncs, path.Join(templatesDir, "basic-search.html"), path.Join(templatesDir, "basic-search.include"))
		if err != nil {
			log.Printf("Can't read basic-search templates, %s\n", err)
			return
		}
	}

	err = tmpl.Execute(w, formData)
	if err != nil {
		responseLogger(r, http.StatusInternalServerError, err)
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte(fmt.Sprintf("%s", err)))
		return
	}
}

func requestLogger(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		//FIXME: add the response status returned.
		q := r.URL.Query()
		if len(q) > 0 {
			log.Printf("Request: %s Path: %s RemoteAddr: %s UserAgent: %s Query: %+v\n", r.Method, r.URL.Path, r.RemoteAddr, r.UserAgent(), q)
		} else {
			log.Printf("Request: %s Path: %s RemoteAddr: %s UserAgent: %s\n", r.Method, r.URL.Path, r.RemoteAddr, r.UserAgent())
		}
		next.ServeHTTP(w, r)
	})
}

func responseLogger(r *http.Request, status int, err error) {
	q := r.URL.Query()
	if len(q) > 0 {
		log.Printf("Response: %s Path: %s RemoteAddr: %s UserAgent: %s Query: %+v Status: %d, %s %q\n", r.Method, r.URL.Path, r.RemoteAddr, r.UserAgent(), q, status, http.StatusText(status), err)
	} else {
		log.Printf("Response: %s Path: %s RemoteAddr: %s UserAgent: %s Status: %d, %s %q\n", r.Method, r.URL.Path, r.RemoteAddr, r.UserAgent(), status, http.StatusText(status), err)
	}
}

// isMultiViewPath checks to see if the path requested behaves like an Apache MultiView request
func isMultiViewPath(p string) bool {
	// check to see if p plus .html extension exists
	fname := fmt.Sprintf("%s.html", p)
	if _, err := os.Stat(path.Join(htdocsDir, fname)); err == nil {
		return true
	}
	return false
}

func multiViewPath(p string) string {
	return fmt.Sprintf("%s.html", p)
}

func customRoutes(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Handle webhook route
		if webhookPath != "" && strings.HasPrefix(r.URL.Path, webhookPath) == true {
			webhookHandler(w, r)
			return
		}

		// Handler are searches and results
		if strings.HasPrefix(r.URL.Path, "/search/results/") == true {
			resultsHandler(w, r)
			return
		}
		if enableSearch == true {
			if strings.HasPrefix(r.URL.Path, "/search/") == true {
				searchHandler(w, r)
				return
			}
		}

		// If this is a MultiViews style request (i.e. missing .html) then update r.URL.Path
		if isMultiViewPath(r.URL.Path) == true {
			p := multiViewPath(r.URL.Path)
			r.URL.Path = p
		}
		// If we make it this far, fall back to the default handler
		next.ServeHTTP(w, r)
	})
}

// switchIndex returns the error if a problem happens swaping the index
func switchIndex() error {
	var (
		curName  string
		nextName string
	)
	curName = index.Name()
	if len(curName) == 0 {
		return fmt.Errorf("No index defined")
	}
	indexList := strings.Split(bleveNames, ":")
	if len(indexList) > 1 {
		// Find the name of the next index
		for i, iName := range indexList {
			if strings.Compare(iName, curName) == 0 {
				i++
				// Wrap to the beginning if we go off end of list
				if i >= len(indexList) {
					i = 0
				}
				nextName = indexList[i]
			}
		}
		log.Printf("Opening index %q", nextName)
		indexNext, err := bleve.Open(nextName)
		if err != nil {
			fmt.Printf("Can't open Bleve index %q, %s, aborting swap", nextName, err)
		} else {
			log.Printf("Switching from %q to %q", curName, nextName)
			indexAlias.Swap([]bleve.Index{indexNext}, []bleve.Index{index})
			log.Printf("Removing %q", index.Name())
			indexAlias.Remove(index)
			log.Printf("Closing %q", curName)
			index.Close()
			// Point index at indexNext
			index = indexNext
			log.Printf("Swap complete, index now %q", index.Name())
		}
		return nil
	}
	return fmt.Errorf("Only %q index defined, no swap possible", curName)
}

func handleSignals() {
	intChan := make(chan os.Signal, 1)
	signal.Notify(intChan, os.Interrupt)
	go func() {
		for {
			<-intChan
			//handle SIGINT by shutting down servepages
			if index != nil {
				log.Printf("Closing index %q", index.Name())
				index.Close()
			}
			log.Println("SIGINT received, shutting down")
			os.Exit(0)
		}
	}()

	termChan := make(chan os.Signal, 1)
	signal.Notify(termChan, syscall.SIGTERM)
	go func() {
		for {
			<-termChan
			//handle SIGTERM by shutting down servepages
			if index != nil {
				log.Printf("Closing index %q", index.Name())
				index.Close()
			}
			log.Println("SIGTERM received, shutting down")
			os.Exit(0)
		}
	}()

	hupChan := make(chan os.Signal, 1)
	signal.Notify(hupChan, syscall.SIGHUP)
	go func() {
		for {
			<-hupChan
			//NOTE: HUP triggers an swap of indexes used by search
			log.Println("SIGHUP received, swaping index")
			err := switchIndex()
			if err != nil {
				log.Printf("Error swaping index %s", err)
				return
			}
			log.Printf("Active Index is now %q", index.Name())
		}
	}()
}

// signBody and verifySignature based on Gist https://gist.github.com/rjz/b51dc03061dbcff1c521
func verifySignature(secret []byte, signature string, body []byte) bool {
	signBody := func(secret, body []byte) []byte {
		computed := hmac.New(sha1.New, secret)
		computed.Write(body)
		return []byte(computed.Sum(nil))
	}

	const signaturePrefix = "sha1="
	const signatureLength = 45 // len(SignaturePrefix) + len(hex(sha1))

	if len(signature) != signatureLength || !strings.HasPrefix(signature, signaturePrefix) {
		return false
	}

	actual := make([]byte, 20)
	hex.Decode(actual, []byte(signature[5:]))

	return hmac.Equal(signBody(secret, body), actual)
}

func webhookHandler(w http.ResponseWriter, r *http.Request) {
	// Always reeturn text/plain OK with a 200 to obscure that this actually is.
	w.Header().Set("Content-Type", "text/plain")
	w.WriteHeader(http.StatusOK)
	fmt.Fprintf(w, "OK")

	log.Printf("Webhook Request: %s Path: %s RemoteAddr: %s UserAgent: %s\n", r.Method, r.URL.Path, r.RemoteAddr, r.UserAgent())
	if strings.Compare(r.Method, "POST") == 0 {
		header := r.Header
		contentType := header.Get("Content-Type")
		xGithubSignature := header.Get("X-Hub-Signature")
		if strings.Compare(contentType, "application/json") == 0 && xGithubSignature != "" {
			body, err := ioutil.ReadAll(r.Body)
			if err == nil && verifySignature([]byte(webhookSecret), xGithubSignature, body) == true {
				log.Printf("Webhook validated, running %q", webhookCommand)
				out, err := exec.Command(webhookCommand).Output()
				if err != nil {
					log.Printf("Webhook error: %s", err)
					return
				}
				log.Printf("Webhook out: %s", out)
				return
			}
		}
	}
	log.Printf("Webhook invalid request method.")
	return
}

func check(cfg *cli.Config, key, value string) string {
	if value == "" {
		log.Fatal("Missing %s_%s", cfg.EnvPrefix, strings.ToUpper(key))
		return ""
	}
	return value
}

func init() {
	// We are going to log to standard out rather than standard err
	log.SetOutput(os.Stdout)

	flag.StringVar(&siteURL, "search", "", "The URL to listen on for search requests")
	flag.StringVar(&bleveNames, "bleve", "", "a colon delimited list of Bleve index db names")
	flag.StringVar(&htdocsDir, "htdocs", "", "specify where to write the HTML files to")
	flag.StringVar(&templatesDir, "templates", "", "The directory path for templates")
	flag.BoolVar(&showHelp, "h", false, "display help")
	flag.BoolVar(&showHelp, "help", false, "display help")
	flag.BoolVar(&showVersion, "v", false, "display version")
	flag.BoolVar(&showVersion, "version", false, "display version")
	flag.BoolVar(&showLicense, "l", false, "display license")
	flag.BoolVar(&showLicense, "license", false, "display license")

	flag.StringVar(&webhookPath, "webhook-path", "", "the webhook path, e.g. /my-webhook/something")
	flag.StringVar(&webhookSecret, "webhook-secret", "", "the secret to validate before executing command")
	flag.StringVar(&webhookCommand, "webhook-command", "", "the command to execute if webhook validates")
	flag.BoolVar(&enableSearch, "enable-search", true, "turn on search support in webserver")
}

func main() {
	var err error

	appName := path.Base(os.Args[0])
	cfg := cli.New(appName, "CAIT", fmt.Sprintf(cait.LicenseText, appName, cait.Version), cait.Version)
	cfg.UsageText = fmt.Sprintf(usage, appName)
	cfg.DescriptionText = fmt.Sprintf(description, appName, appName)
	cfg.OptionsText = "OPTIONS\n"

	flag.Parse()
	if showHelp == true {
		fmt.Println(cfg.Usage())
		os.Exit(0)
	}
	if showVersion == true {
		fmt.Println(cfg.Version())
		os.Exit(0)
	}

	if showLicense == true {
		fmt.Println(cfg.License())
		os.Exit(0)
	}

	siteURL = check(cfg, "site_url", cfg.MergeEnv("site_url", siteURL))
	serviceURL, err := url.Parse(siteURL)
	if err != nil {
		log.Fatal(err)
	}
	htdocsDir = check(cfg, "htdocs", cfg.MergeEnv("htdocs", htdocsDir))
	bleveNames = check(cfg, "bleve", cfg.MergeEnv("bleve", bleveNames))
	templatesDir = check(cfg, "templates", cfg.MergeEnv("templates", templatesDir))
	webhookPath = cfg.MergeEnv("webhook_path", webhookPath)
	webhookSecret = cfg.MergeEnv("webhook_secret", webhookSecret)
	webhookCommand = cfg.MergeEnv("webhook_command", webhookCommand)

	templateName := path.Join(templatesDir, "advanced-search.html")
	advancedPage, err = ioutil.ReadFile(templateName)
	if err != nil {
		log.Fatalf("Can't read templates, e.g. %s, %s", templateName, err)
	}
	templateName = path.Join(templatesDir, "basic-search.html")
	basicPage, err = ioutil.ReadFile(templateName)
	if err != nil {
		log.Fatalf("Can't read %s, %s", templateName, err)
	}

	handleSignals()

	// Wake up our search engine
	indexList := strings.Split(bleveNames, ":")
	availableIndex := false
	if enableSearch == true {
		for i := 0; i < len(indexList) && availableIndex == false; i++ {
			indexName := indexList[i]
			log.Printf("Opening %q", indexName)
			index, err = bleve.Open(indexName)
			if err != nil {
				log.Printf("Can't open Bleve index %q, %s, trying next index", indexName, err)
			} else {
				indexAlias = bleve.NewIndexAlias(index)
				availableIndex = true
			}
		}
		if availableIndex == false {
			log.Fatalf("No index available %s", bleveNames)
		}
		defer index.Close()
	}

	// Send static file request to the default handler,
	// search routes are handled by middleware customRoutes()
	http.Handle("/", http.FileServer(http.Dir(htdocsDir)))

	log.Printf("%s %s\n", appName, cait.Version)
	log.Printf("Listening on %s\n", serviceURL.String())
	err = http.ListenAndServe(serviceURL.Host, requestLogger(customRoutes(http.DefaultServeMux)))
	if err != nil {
		log.Fatal(err)
	}
}