Make listen address configurable

The evaluator is the main part of this, so it doesn’t have to be in a
subdirectory.

.drone.yml

@@ -1,31 +0,0 @@
-kind: pipeline
-name: default
-
-steps:
-  - name: build
-    image: mikefarah/yq
-    commands:
-      - yq r -j bangs.yml > bangs.json
-
-  - name: upload
-    image: plugins/s3
-    settings:
-      bucket: cdn
-      access_key:
-        from_secret: aws_access_key_id
-      secret_key:
-        from_secret: aws_secret_access_key
-      source: bangs.json
-      target: /bangs/
-      path_style: true
-      endpoint: https://s3.sbruder.de
-
-  - name: docker
-    image: plugins/docker
-    settings:
-      registry: r.sbruder.de
-      username:
-        from_secret: docker_username
-      password:
-        from_secret: docker_password
-      repo: r.sbruder.de/bang-evaluator

.gitignore

@@ -1 +1,3 @@
-bangs.json
+/vendor/
+/bangs.go
+/result*

Dockerfile

@@ -1,22 +0,0 @@
-FROM golang:alpine as builder
-
-WORKDIR /go/src/git.sbruder.de/simon/bangs/evaluator/
-
-COPY evaluator/evaluator.go .
-
-RUN apk add --no-cache git upx
-
-RUN go get -v \
-    && CGO_ENABLED=0 go build -v -ldflags="-s -w" \
-    && upx --ultra-brute evaluator
-
-FROM scratch
-
-COPY --from=builder /go/src/git.sbruder.de/simon/bangs/evaluator/evaluator /evaluator
-copy bangs.json /bangs.json
-
-USER 1000
-
-ENTRYPOINT ["/evaluator"]
-
-EXPOSE 8081

default.nix

@@ -0,0 +1,23 @@
+{ pkgs ? import <nixpkgs> { } }:
+let
+  gitignoreSrc = pkgs.fetchFromGitHub {
+    owner = "hercules-ci";
+    repo = "gitignore";
+    rev = "c4662e662462e7bf3c2a968483478a665d00e717";
+    sha256 = "1npnx0h6bd0d7ql93ka7azhj40zgjp815fw2r6smg8ch9p7mzdlx";
+  };
+  inherit (import gitignoreSrc { inherit (pkgs) lib; }) gitignoreSource;
+in
+pkgs.buildGoModule {
+  name = "bang-evaluator";
+
+  src = gitignoreSource ./.; # FIXME: reproducibility
+
+  subPackages = [ "." ];
+
+  vendorSha256 = "11r1l5lcdfm3wymrkbddl5khpjmr30jln31l40mfyyy9msnqayf3";
+
+  preBuild = ''go generate ./...'';
+
+  doCheck = false; # no tests (yet?)
+}

evaluator.go

@@ -1,23 +1,22 @@
 package main
 
 import (
-	"encoding/json"
-	"io/ioutil"
 	"log"
 	"net/http"
 	"net/url"
+	"os"
 	"regexp"
 	"strings"
 )
 
-var bangs = loadBangs()
+//go:generate go run scripts/includebangs.go
 
 func main() {
 	http.HandleFunc("/eval", func(w http.ResponseWriter, r *http.Request) {
 		searchQuery := r.URL.Query().Get("query")
 		searchEngine := r.URL.Query().Get("engine")
 
-		if (searchQuery == "" || searchEngine == "") {
+		if searchQuery == "" || searchEngine == "" {
 			http.Error(w, "400 Bad Request", http.StatusBadRequest)
 			return
 		}
@@ -28,23 +27,24 @@ func main() {
 		http.Redirect(w, r, searchURL, http.StatusSeeOther)
 	})
 
-	log.Fatalf("Failed to start http server: %v", http.ListenAndServe(":8081", nil))
+	listenAddress := getSetting("LISTEN_ADDRESS", ":8081")
+	log.Printf("Listening at %s", listenAddress)
+
+	log.Fatalf("Failed to start http server: %v", http.ListenAndServe(listenAddress, nil))
 }
 
-func loadBangs() (bangs map[string]string) {
-	data, err := ioutil.ReadFile("bangs.json")
-    if err != nil {
-		log.Fatalf("Failed to read bangs: %v", err)
+func getenv(name string, fallback string) (value string) {
+	value = os.Getenv(name)
+	if value == "" {
+		return fallback
 	}
-
-	err = json.Unmarshal(data, &bangs)
-	if err != nil {
-		log.Fatalf("Failed to decode bangs: %v", err)
-	}
-
 	return
 }
 
+func getSetting(name, fallback string) (value string) {
+	return getenv("BANG_EVALUATOR_"+name, fallback)
+}
+
 func buildSearchURL(template string, query string) (searchUrl string) {
 	searchUrl = strings.Replace(template, "%s", url.QueryEscape(query), 1)
 	searchUrl = strings.Replace(searchUrl, "%S", query, 1)
@@ -73,9 +73,9 @@ func parseBang(searchQuery string) (bang string, query string) {
 
 func evaluateBang(searchQuery string, searchEngine string) (query string, engine string) {
 	bang, query := parseBang(searchQuery)
-	engine = bangs[bang]
+	engine = getBang(bang)
 
-	if (bang == "" || engine == ""){
+	if bang == "" || engine == "" {
 		return searchQuery, searchEngine
 	} else {
 		return query, engine

go.mod

@@ -0,0 +1,5 @@
+module git.sbruder.de/simon/bangs/evaluator
+
+go 1.15
+
+require gopkg.in/yaml.v2 v2.4.0

go.sum

@@ -0,0 +1,3 @@
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=

scripts/includebangs.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"sort"
+
+	"gopkg.in/yaml.v2"
+)
+
+func loadBangs() (bangs map[string]string) {
+	data, err := ioutil.ReadFile("bangs.yml")
+	if err != nil {
+		panic(fmt.Sprintf("Failed to load bangs.yml: %v", err))
+	}
+
+	err = yaml.Unmarshal(data, &bangs)
+	if err != nil {
+		panic(fmt.Sprintf("Failed to decode bangs: %v", err))
+	}
+
+	return
+}
+
+func main() {
+	bangs := loadBangs()
+
+	// generating sorted keys to have stable generated code
+	// this is not optimal, performance-wise but it runs only once at build
+	// time, so it doesn’t matter that much)
+	bangNames := []string{}
+	for bang := range bangs {
+		bangNames = append(bangNames, bang)
+	}
+	sort.Strings(bangNames)
+
+	out, err := os.Create("bangs.go")
+	if err != nil {
+		panic(fmt.Sprintf("Failed to create bangs.go: %v", err))
+	}
+
+	out.Write([]byte("// Code generated from ../bangs.yml DO NOT EDIT.\n"))
+	out.Write([]byte("package main \n\nfunc getBang(name string) string {\n\tswitch name {\n"))
+
+	for _, bangName := range bangNames {
+		out.Write([]byte("\t\tcase `" + bangName + "`: return `" + bangs[bangName] + "`\n"))
+	}
+	out.Write([]byte("\t\tdefault: return \"\"\n"))
+	out.Write([]byte("\t}\n}\n"))
+}

startpage.user.js

@@ -1,38 +0,0 @@
-// ==UserScript==
-// @name     Startpage Bangs
-// @version  1
-// @grant    none
-// @run-at   document-start
-// @include  https://*.startpage.com/*
-// ==/UserScript==
-
-fetch('https://s3.sbruder.de/cdn/bangs/bangs.json')
-  .then(text => text.json())
-  .then(bangs => {
-  const urlParams = new URLSearchParams(window.location.search)
-  const searchQuery = urlParams.get('query')
-
-  let matchBang = null
-  let parsedBang = null
-
-  matchBang = searchQuery.match(/(.*) \!(.*)/)
-  if (matchBang !== null) {
-    parsedBang = {
-      'bang': matchBang[2].toLowerCase(),
-      'query': matchBang[1]
-    }
-  }
-
-  matchBang = searchQuery.match(/\!(.*) (.*)/)
-  if (matchBang !== null) {
-    parsedBang = {
-      'bang': matchBang[1].toLowerCase(),
-      'query': matchBang[2]
-    }
-  }
-
-  if (parsedBang !== null) {
-    redirectURL = bangs[parsedBang.bang].replace('%s', encodeURI(parsedBang.query)).replace('%S', parsedBang.query)
-    window.location.replace(redirectURL);
-  }
-})