Refactor config package

- Parse configuration only once during startup time
- Store configuration values in a global variable

config/parser.go

@@ -0,0 +1,124 @@
+// Copyright 2019 Frédéric Guillot. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package config // import "miniflux.app/config"
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func parse() (opts *Options, err error) {
+	opts = &Options{}
+	opts.baseURL, opts.rootURL, opts.basePath, err = parseBaseURL()
+	if err != nil {
+		return nil, err
+	}
+
+	opts.debug = getBooleanValue("DEBUG")
+	opts.listenAddr = parseListenAddr()
+
+	opts.databaseURL = getStringValue("DATABASE_URL", defaultDatabaseURL)
+	opts.databaseMaxConns = getIntValue("DATABASE_MAX_CONNS", defaultDatabaseMaxConns)
+	opts.databaseMinConns = getIntValue("DATABASE_MIN_CONNS", defaultDatabaseMinConns)
+	opts.runMigrations = getBooleanValue("RUN_MIGRATIONS")
+
+	opts.hsts = !getBooleanValue("DISABLE_HSTS")
+	opts.HTTPS = getBooleanValue("HTTPS")
+
+	opts.schedulerService = !getBooleanValue("DISABLE_SCHEDULER_SERVICE")
+	opts.httpService = !getBooleanValue("DISABLE_HTTP_SERVICE")
+
+	opts.certFile = getStringValue("CERT_FILE", defaultCertFile)
+	opts.certKeyFile = getStringValue("KEY_FILE", defaultKeyFile)
+	opts.certDomain = getStringValue("CERT_DOMAIN", defaultCertDomain)
+	opts.certCache = getStringValue("CERT_CACHE", defaultCertCache)
+
+	opts.cleanupFrequency = getIntValue("CLEANUP_FREQUENCY", defaultCleanupFrequency)
+	opts.workerPoolSize = getIntValue("WORKER_POOL_SIZE", defaultWorkerPoolSize)
+	opts.pollingFrequency = getIntValue("POLLING_FREQUENCY", defaultPollingFrequency)
+	opts.batchSize = getIntValue("BATCH_SIZE", defaultBatchSize)
+	opts.archiveReadDays = getIntValue("ARCHIVE_READ_DAYS", defaultArchiveReadDays)
+	opts.proxyImages = getStringValue("PROXY_IMAGES", defaultProxyImages)
+
+	opts.oauth2UserCreationAllowed = getBooleanValue("OAUTH2_USER_CREATION")
+	opts.oauth2ClientID = getStringValue("OAUTH2_CLIENT_ID", defaultOAuth2ClientID)
+	opts.oauth2ClientSecret = getStringValue("OAUTH2_CLIENT_SECRET", defaultOAuth2ClientSecret)
+	opts.oauth2RedirectURL = getStringValue("OAUTH2_REDIRECT_URL", defaultOAuth2RedirectURL)
+	opts.oauth2Provider = getStringValue("OAUTH2_PROVIDER", defaultOAuth2Provider)
+
+	opts.pocketConsumerKey = getStringValue("POCKET_CONSUMER_KEY", "")
+
+	opts.createAdmin = getBooleanValue("CREATE_ADMIN")
+
+	return opts, nil
+}
+
+func parseBaseURL() (string, string, string, error) {
+	baseURL := os.Getenv("BASE_URL")
+	if baseURL == "" {
+		return defaultBaseURL, defaultBaseURL, "", nil
+	}
+
+	if baseURL[len(baseURL)-1:] == "/" {
+		baseURL = baseURL[:len(baseURL)-1]
+	}
+
+	u, err := url.Parse(baseURL)
+	if err != nil {
+		return "", "", "", fmt.Errorf("Invalid BASE_URL: %v", err)
+	}
+
+	scheme := strings.ToLower(u.Scheme)
+	if scheme != "https" && scheme != "http" {
+		return "", "", "", errors.New("Invalid BASE_URL: scheme must be http or https")
+	}
+
+	basePath := u.Path
+	u.Path = ""
+	return baseURL, u.String(), basePath, nil
+}
+
+func parseListenAddr() string {
+	if port := os.Getenv("PORT"); port != "" {
+		return ":" + port
+	}
+
+	return getStringValue("LISTEN_ADDR", defaultListenAddr)
+}
+
+func getBooleanValue(key string) bool {
+	value := strings.ToLower(os.Getenv(key))
+	if value == "1" || value == "yes" || value == "true" || value == "on" {
+		return true
+	}
+	return false
+}
+
+func getStringValue(key, fallback string) string {
+	value := os.Getenv(key)
+	if value == "" {
+		return fallback
+	}
+
+	return value
+}
+
+func getIntValue(key string, fallback int) int {
+	value := os.Getenv(key)
+	if value == "" {
+		return fallback
+	}
+
+	v, err := strconv.Atoi(value)
+	if err != nil {
+		return fallback
+	}
+
+	return v
+}