Bump gin to v1.9.0

Bumps [github.com/containerd/containerd](https://github.com/containerd/containerd) from 1.6.12 to 1.6.18.

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,50 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ "main" ]
+  schedule:
+    - cron: '21 21 * * 0'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v3
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v2
+      with:
+        languages: go
+
+    - run: |
+       echo "Build"
+       make build
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v2

.github/workflows/main.yml

@@ -11,19 +11,20 @@ on:
 jobs:
   tests:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        make: ["lint", "test"]
     steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
 
       - name: install go
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v3
         with:
-          go-version: "^1.17"
+          go-version-file: go.mod
+          cache: true
 
-      - name: Lint
-        run: make lint
-
-      - name: Tests
-        run: make test
+      - name: ${{ matrix.make }}
+        run: make ${{ matrix.make }}
 
   deploy:
     runs-on: ubuntu-latest
@@ -33,7 +34,7 @@ jobs:
       matrix:
         goosarch: [linux-amd64]
     steps:
-      - uses: actions/checkout@v2.4.0
+      - uses: actions/checkout@v3
         with:
           fetch-depth: 0
 
@@ -51,7 +52,7 @@ jobs:
 
       - name: Prepare release
         run: |
-          git log $(git describe HEAD~ --tags --abbrev=0)..HEAD --pretty='format:%h - %s (%cr) <%an>' --no-merges > changelog.txt
+          git log $(git describe HEAD~ --tags --abbrev=0)..HEAD --pretty='format:%h - %s <%an>' --no-merges > changelog.txt
           tar  zcvf whatismyip-$RELEASE_VERSION-${{matrix.goosarch}}.tar.gz whatismyip LICENSE README.md
           sha256sum whatismyip-$RELEASE_VERSION-${{matrix.goosarch}}.tar.gz > whatismyip-$RELEASE_VERSION-${{matrix.goosarch}}.tar.gz.sha256
 

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.17-alpine as builder
+FROM golang:1.20-alpine as builder
 
 ARG ARG_VERSION
 ENV VERSION $ARG_VERSION
@@ -7,7 +7,7 @@ WORKDIR /app
 
 COPY . .
 
-RUN apk add make && make build VERSION=$VERSION
+RUN apk add make git && make build VERSION=$VERSION
 
 # Build final image
 FROM scratch

Makefile

@@ -16,14 +16,20 @@ integration-test:
 .PHONY: install-tools
 install-tools:
 	@command golangci-lint > /dev/null 2>&1; if [ $$? -ne 0 ]; then \
-		curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(GOPATH)/bin v1.43.0; \
+		curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(GOPATH)/bin; \
 	fi
 
 	@command $(GOPATH)/shadow > /dev/null 2>&1; if [ $$? -ne 0 ]; then \
-		go install golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow@v0.1.7; \
+		go install golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow@latest; \
+	fi
+
+	@command $(GOPATH)/golines > /dev/null 2>&1; if [ $$? -ne 0 ]; then \
+		go install github.com/segmentio/golines@latest; \
 	fi
 .PHONY: lint
 lint: install-tools
+	gofmt -l . && test -z $$(gofmt -l .)
+	golines -l . && test -z $$(golines -l .)
 	golangci-lint run
 	shadow ./...
 

README.md

@@ -1,5 +1,11 @@
 # What is my IP address
 
+[![CI](https://github.com/dcarrillo/whatismyip/workflows/CI/badge.svg)](https://github.com/dcarrillo/whatismyip/actions)
+[![CodeQL](https://github.com/dcarrillo/whatismyip/actions/workflows/codeql-analysis.yml/badge.svg)](https://github.com/dcarrillo/whatismyip/actions/workflows/codeql-analysis.yml)
+[![Go Report Card](https://goreportcard.com/badge/github.com/dcarrillo/whatismyip)](https://goreportcard.com/report/github.com/dcarrillo/whatismyip)
+[![GitHub release](https://img.shields.io/github/release/dcarrillo/whatismyip.svg)](https://github.com/dcarrillo/whatismyip/releases/)
+[![License Apache 2.0](https://img.shields.io/badge/license-Apache%202.0-blue.svg)](./LICENSE)
+
 - [What is my IP address](#what-is-my-ip-address)
   - [Features](#features)
   - [Endpoints](#endpoints)
@@ -8,10 +14,10 @@
   - [Examples](#examples)
     - [Run a default TCP server](#run-a-default-tcp-server)
     - [Run a TLS (HTTP/2) server only](#run-a-tls-http2-server-only)
-    - [Run a default TCP server with a custom template and trust a custom header set by an upstream proxy](#run-a-default-tcp-server-with-a-custom-template-and-trust-a-custom-header-set-by-an-upstream-proxy)
+    - [Run a default TCP server with a custom template and trust a pair of custom headers set by an upstream proxy](#run-a-default-tcp-server-with-a-custom-template-and-trust-a-pair-of-custom-headers-set-by-an-upstream-proxy)
   - [Download](#download)
   - [Docker](#docker)
-    - [Running a container locally using test databases](#running-a-container-locally-using-test-databases)
+    - [Run a container locally using test databases](#run-a-container-locally-using-test-databases)
     - [From Docker Hub](#from-docker-hub)
 
 Just another "what is my IP address" service, including geolocation and headers information, written in go with high performance in mind, it uses [gin](https://github.com/gin-gonic/gin) which uses [httprouter](https://github.com/julienschmidt/httprouter) a lightweight high performance HTTP multiplexer.
@@ -31,7 +37,7 @@ curl -6 ifconfig.es
 ## Features
 
 - TLS and HTTP/2.
-- Can run behind a proxy by trusting a custom header (usually `X-Real-IP`) to figure out the source IP address.
+- Can run behind a proxy by trusting a custom header (usually `X-Real-IP`) to figure out the source IP address. It also supports a custom header to resolve the client port, if the proxy can only add a header for the IP (for example a fixed header from CDNs) the client port is shown as unknown.
 - IPv4 and IPv6.
 - Geolocation info including ASN. This feature is possible thanks to [maxmind](https://dev.maxmind.com/geoip/geolite2-free-geolocation-data?lang=en) GeoLite2 databases. In order to use these databases, a license key is needed. Please visit Maxmind site for further instructions and get a free license.
 - High performance.
@@ -42,7 +48,8 @@ curl -6 ifconfig.es
 ## Endpoints
 
 - https://ifconfig.es/
-- https://ifconfig.es/json
+- https://ifconfig.es/client-port
+- https://ifconfig.es/json (this is the same as `curl -H "Accept: application/json" https://ifconfig.es/`)
 - https://ifconfig.es/geo
   - https://ifconfig.es/geo/city
   - https://ifconfig.es/geo/country
@@ -67,9 +74,11 @@ Golang >= 1.17 is required. Previous versions may work.
 ## Usage
 
 ```text
-Usage of ./whatismyip:
+Usage of whatismyip:
   -bind string
         Listening address (see https://pkg.go.dev/net?#Listen) (default ":8080")
+  -enable-secure-headers
+        Add sane security-related headers to every response
   -geoip2-asn string
         Path to GeoIP2 ASN database
   -geoip2-city string
@@ -83,7 +92,9 @@ Usage of ./whatismyip:
   -tls-key string
         When using TLS, path to private key file
   -trusted-header string
-        Trusted request header for remote IP (e.g. X-Real-IP)
+        Trusted request header for remote IP (e.g. X-Real-IP). When using this feature if -trusted-port-header is not set the client port is shown as 'unknown'
+  -trusted-port-header string
+        Trusted request header for remote client port (e.g. X-Real-Port). When this parameter is set -trusted-header becomes mandatory
   -version
         Output version information and exit
 ```
@@ -99,13 +110,15 @@ Usage of ./whatismyip:
 ### Run a TLS (HTTP/2) server only
 
 ```bash
-./whatismyip -geoip2-city ./test/GeoIP2-City-Test.mmdb -geoip2-asn ./test/GeoLite2-ASN-Test.mmdb -bind "" -tls-bind :8081 -tls-crt ./test/server.pem -tls-key ./test/server.key
+./whatismyip -geoip2-city ./test/GeoIP2-City-Test.mmdb -geoip2-asn ./test/GeoLite2-ASN-Test.mmdb \
+             -bind "" -tls-bind :8081 -tls-crt ./test/server.pem -tls-key ./test/server.key
 ```
 
-### Run a default TCP server with a custom template and trust a custom header set by an upstream proxy
+### Run a default TCP server with a custom template and trust a pair of custom headers set by an upstream proxy
 
 ```bash
-./whatismyip -geoip2-city ./test/GeoIP2-City-Test.mmdb -geoip2-asn ./test/GeoLite2-ASN-Test.mmdb -trusted-header X-Real-IP -template mytemplate.tmpl
+./whatismyip -geoip2-city ./test/GeoIP2-City-Test.mmdb -geoip2-asn ./test/GeoLite2-ASN-Test.mmdb \
+             -trusted-header X-Real-IP -trusted-port-header X-Real-Port -template mytemplate.tmpl
 ```
 
 ## Download
@@ -114,9 +127,9 @@ Download latest version from https://github.com/dcarrillo/whatismyip/releases
 
 ## Docker
 
-An ultra-light (~9MB) image is available.
+An ultra-light (~10MB) image is available at [docker hub](https://hub.docker.com/r/dcarrillo/whatismyip).
 
-### Running a container locally using test databases
+### Run a container locally using test databases
 
 `make docker-run`
 
@@ -127,6 +140,6 @@ docker run --tty --interactive --rm \
     -v $PWD/<path to city database>:/tmp/GeoIP2-City-Test.mmdb:ro \
     -v $PWD/<path to ASN database>:/tmp/GeoLite2-ASN-Test.mmdb:ro -p 8080:8080 \
     dcarrillo/whatismyip:latest \
-    -geoip2-city /tmp/GeoIP2-City-Test.mmdb \
-    -geoip2-asn /tmp/GeoLite2-ASN-Test.mmdb
+      -geoip2-city /tmp/GeoIP2-City-Test.mmdb \
+      -geoip2-asn /tmp/GeoLite2-ASN-Test.mmdb
 ```

cmd/whatismyip.go

@@ -3,6 +3,8 @@ package main
 import (
 	"context"
 	"errors"
+	"flag"
+	"fmt"
 	"log"
 	"net/http"
 	"os"
@@ -11,6 +13,8 @@ import (
 
 	"github.com/dcarrillo/whatismyip/internal/httputils"
 	"github.com/dcarrillo/whatismyip/internal/setting"
+	"github.com/gin-contrib/secure"
+
 	"github.com/dcarrillo/whatismyip/models"
 	"github.com/dcarrillo/whatismyip/router"
 
@@ -24,7 +28,15 @@ var (
 )
 
 func main() {
-	setting.Setup()
+	o, err := setting.Setup(os.Args[1:])
+	if err == flag.ErrHelp || err == setting.ErrVersion {
+		fmt.Print(o)
+		os.Exit(0)
+	} else if err != nil {
+		fmt.Print(err)
+		os.Exit(1)
+	}
+
 	models.Setup(setting.App.GeodbPath.City, setting.App.GeodbPath.ASN)
 	setupEngine()
 	router.SetupTemplate(engine)
@@ -128,6 +140,13 @@ func setupEngine() {
 	engine = gin.New()
 	engine.Use(gin.LoggerWithFormatter(httputils.GetLogFormatter))
 	engine.Use(gin.Recovery())
+	if setting.App.EnableSecureHeaders {
+		engine.Use(secure.New(secure.Config{
+			BrowserXssFilter:   true,
+			ContentTypeNosniff: true,
+			FrameDeny:          true,
+		}))
+	}
 	_ = engine.SetTrustedProxies(nil)
 	engine.TrustedPlatform = setting.App.TrustedHeader
 }

go.mod

@@ -1,59 +1,66 @@
 module github.com/dcarrillo/whatismyip
 
-go 1.17
+go 1.20
 
 require (
-	github.com/gin-gonic/gin v1.7.2-0.20211103141324-89a159bdd92c
-	github.com/oschwald/maxminddb-golang v1.8.0
-	github.com/stretchr/testify v1.7.0
-	github.com/testcontainers/testcontainers-go v0.11.1
+	github.com/gin-contrib/secure v0.0.1
+	github.com/gin-gonic/gin v1.9.0
+	github.com/oschwald/maxminddb-golang v1.10.0
+	github.com/stretchr/testify v1.8.2
+	github.com/testcontainers/testcontainers-go v0.13.0
 )
 
 require (
-	github.com/Azure/go-ansiterm v0.0.0-20170929234023-d6e3b3328b78 // indirect
-	github.com/Microsoft/go-winio v0.4.17-0.20210211115548-6eac466e5fa3 // indirect
-	github.com/Microsoft/hcsshim v0.8.16 // indirect
-	github.com/cenkalti/backoff v2.2.1+incompatible // indirect
-	github.com/containerd/cgroups v0.0.0-20210114181951-8a68de567b68 // indirect
-	github.com/containerd/containerd v1.5.0-beta.4 // indirect
+	github.com/Azure/go-ansiterm v0.0.0-20210617225240-d185dfc1b5a1 // indirect
+	github.com/Microsoft/go-winio v0.5.2 // indirect
+	github.com/Microsoft/hcsshim v0.9.6 // indirect
+	github.com/bytedance/sonic v1.8.3 // indirect
+	github.com/cenkalti/backoff/v4 v4.1.3 // indirect
+	github.com/chenzhuoyu/base64x v0.0.0-20221115062448-fe3a3abad311 // indirect
+	github.com/containerd/cgroups v1.0.4 // indirect
+	github.com/containerd/containerd v1.6.18 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/docker/distribution v2.7.1+incompatible // indirect
-	github.com/docker/docker v20.10.7+incompatible // indirect
+	github.com/docker/distribution v2.8.1+incompatible // indirect
+	github.com/docker/docker v20.10.17+incompatible // indirect
 	github.com/docker/go-connections v0.4.0 // indirect
 	github.com/docker/go-units v0.4.0 // indirect
 	github.com/gin-contrib/sse v0.1.0 // indirect
-	github.com/go-playground/locales v0.14.0 // indirect
-	github.com/go-playground/universal-translator v0.18.0 // indirect
-	github.com/go-playground/validator/v10 v10.9.0 // indirect
-	github.com/goccy/go-json v0.7.10 // indirect
+	github.com/go-playground/locales v0.14.1 // indirect
+	github.com/go-playground/universal-translator v0.18.1 // indirect
+	github.com/go-playground/validator/v10 v10.11.2 // indirect
+	github.com/goccy/go-json v0.10.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
-	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
-	github.com/golang/protobuf v1.5.0 // indirect
-	github.com/google/uuid v1.2.0 // indirect
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/uuid v1.3.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/leodido/go-urn v1.2.1 // indirect
-	github.com/mattn/go-isatty v0.0.14 // indirect
-	github.com/moby/sys/mount v0.2.0 // indirect
-	github.com/moby/sys/mountinfo v0.4.1 // indirect
-	github.com/moby/term v0.0.0-20201216013528-df9cb8a40635 // indirect
+	github.com/klauspost/cpuid/v2 v2.2.4 // indirect
+	github.com/leodido/go-urn v1.2.2 // indirect
+	github.com/magiconair/properties v1.8.6 // indirect
+	github.com/mattn/go-isatty v0.0.17 // indirect
+	github.com/moby/sys/mount v0.3.3 // indirect
+	github.com/moby/sys/mountinfo v0.6.2 // indirect
+	github.com/moby/term v0.0.0-20220808134915-39b0c02b01ae // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
-	github.com/morikuni/aec v0.0.0-20170113033406-39771216ff4c // indirect
+	github.com/morikuni/aec v1.0.0 // indirect
 	github.com/opencontainers/go-digest v1.0.0 // indirect
-	github.com/opencontainers/image-spec v1.0.1 // indirect
-	github.com/opencontainers/runc v1.0.0-rc93 // indirect
+	github.com/opencontainers/image-spec v1.0.3-0.20211202183452-c5a74bcca799 // indirect
+	github.com/opencontainers/runc v1.1.3 // indirect
+	github.com/pelletier/go-toml/v2 v2.0.7 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/sirupsen/logrus v1.7.0 // indirect
-	github.com/ugorji/go/codec v1.2.6 // indirect
-	go.opencensus.io v0.22.3 // indirect
-	golang.org/x/crypto v0.0.0-20210921155107-089bfa567519 // indirect
-	golang.org/x/net v0.0.0-20210226172049-e18ecbb05110 // indirect
-	golang.org/x/sys v0.0.0-20211025201205-69cdffdb9359 // indirect
-	golang.org/x/text v0.3.7 // indirect
-	google.golang.org/genproto v0.0.0-20201110150050-8816d57aaa9a // indirect
-	google.golang.org/grpc v1.33.2 // indirect
-	google.golang.org/protobuf v1.27.1 // indirect
-	gopkg.in/yaml.v2 v2.4.0 // indirect
-	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
+	github.com/sirupsen/logrus v1.9.0 // indirect
+	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
+	github.com/ugorji/go/codec v1.2.11 // indirect
+	go.opencensus.io v0.23.0 // indirect
+	golang.org/x/arch v0.3.0 // indirect
+	golang.org/x/crypto v0.7.0 // indirect
+	golang.org/x/net v0.8.0 // indirect
+	golang.org/x/sys v0.6.0 // indirect
+	golang.org/x/text v0.8.0 // indirect
+	google.golang.org/genproto v0.0.0-20220810155839-1856144b1d9c // indirect
+	google.golang.org/grpc v1.48.0 // indirect
+	google.golang.org/protobuf v1.29.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

integration-tests/integration_test.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"path/filepath"
@@ -19,7 +19,7 @@ import (
 
 func buildContainer() testcontainers.ContainerRequest {
 	_, filename, _, _ := runtime.Caller(0)
-	dirname := filepath.Dir(filename)
+	dir := filepath.Dir(filename)
 
 	req := testcontainers.ContainerRequest{
 		FromDockerfile: testcontainers.FromDockerfile{
@@ -34,15 +34,22 @@ func buildContainer() testcontainers.ContainerRequest {
 			"-tls-crt", "/tmp/server.pem",
 			"-tls-key", "/tmp/server.key",
 			"-trusted-header", "X-Real-IP",
+			"-enable-secure-headers",
 		},
 		ExposedPorts: []string{"8000:8000", "8001:8001"},
 		WaitingFor:   wait.ForLog("Starting TLS server listening on :8001"),
-		BindMounts: map[string]string{
-			filepath.Join(dirname, "/../test/GeoIP2-City-Test.mmdb"):  "/tmp/GeoIP2-City-Test.mmdb",
-			filepath.Join(dirname, "/../test/GeoLite2-ASN-Test.mmdb"): "/tmp/GeoLite2-ASN-Test.mmdb",
-			filepath.Join(dirname, "/../test/server.pem"):             "/tmp/server.pem",
-			filepath.Join(dirname, "/../test/server.key"):             "/tmp/server.key",
-		},
+		Mounts: testcontainers.Mounts(
+			testcontainers.BindMount(
+				filepath.Join(dir, "/../test/GeoIP2-City-Test.mmdb"),
+				"/tmp/GeoIP2-City-Test.mmdb",
+			),
+			testcontainers.BindMount(
+				filepath.Join(dir, "/../test/GeoLite2-ASN-Test.mmdb"),
+				"/tmp/GeoLite2-ASN-Test.mmdb",
+			),
+			testcontainers.BindMount(filepath.Join(dir, "/../test/server.pem"), "/tmp/server.pem"),
+			testcontainers.BindMount(filepath.Join(dir, "/../test/server.key"), "/tmp/server.key"),
+		),
 	}
 
 	return req
@@ -69,16 +76,21 @@ func TestContainerIntegration(t *testing.T) {
 	}()
 
 	http.DefaultTransport.(*http.Transport).TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
-	for _, url := range []string{"http://localhost:8000/json", "https://localhost:8001/json"} {
-		resp, _ := http.Get(url)
+	for _, url := range []string{"http://localhost:8000", "https://localhost:8001"} {
+		client := &http.Client{}
+		req, _ := http.NewRequest("GET", url, nil)
+		req.Header.Set("Accept", "application/json")
+		resp, _ := client.Do(req)
 		assert.Equal(t, 200, resp.StatusCode)
 
-		var dat router.JSONResponse
-		body, err := ioutil.ReadAll(resp.Body)
+		body, err := io.ReadAll(resp.Body)
 		if err != nil {
 			log.Fatal(err)
 		}
 
-		assert.NoError(t, json.Unmarshal(body, &dat))
+		assert.NoError(t, json.Unmarshal(body, &router.JSONResponse{}))
+		assert.Equal(t, "DENY", resp.Header.Get("X-Frame-Options"))
+		assert.Equal(t, "nosniff", resp.Header.Get("X-Content-Type-Options"))
+		assert.Equal(t, "1; mode=block", resp.Header.Get("X-Xss-Protection"))
 	}
 }

internal/core/version.go

@@ -1,3 +1,4 @@
 package core
 
+// Version to be defined at build time
 var Version = "tobedefined"

internal/httputils/http.go

@@ -3,12 +3,15 @@ package httputils
 import (
 	"fmt"
 	"net/http"
+	"net/textproto"
 	"sort"
 	"strings"
 
+	"github.com/dcarrillo/whatismyip/internal/setting"
 	"github.com/gin-gonic/gin"
 )
 
+// HeadersToSortedString shorts and dumps http.Header to a string separated by \n
 func HeadersToSortedString(headers http.Header) string {
 	var output string
 
@@ -31,6 +34,18 @@ func HeadersToSortedString(headers http.Header) string {
 	return output
 }
 
+// GetHeadersWithoutTrustedHeaders return a http.Heade object with the original headers except trusted headers
+func GetHeadersWithoutTrustedHeaders(ctx *gin.Context) http.Header {
+	h := ctx.Request.Header
+
+	for _, k := range []string{setting.App.TrustedHeader, setting.App.TrustedPortHeader} {
+		delete(h, textproto.CanonicalMIMEHeaderKey(k))
+	}
+
+	return h
+}
+
+// GetLogFormatter returns our custom log format
 func GetLogFormatter(param gin.LogFormatterParams) string {
 	return fmt.Sprintf("%s - [%s] \"%s %s %s\" %d %d %d %s \"%s\" \"%s\" \"%s\"\n",
 		param.ClientIP,
@@ -57,9 +72,8 @@ func normalizeLog(log interface{}) interface{} {
 	case []string:
 		if len(v) == 0 {
 			return "-"
-		} else {
-			return strings.Join(v, ", ")
 		}
+		return strings.Join(v, ", ")
 	}
 
 	return log

internal/setting/app.go

@@ -1,6 +1,8 @@
 package setting
 
 import (
+	"bytes"
+	"errors"
 	"flag"
 	"fmt"
 	"os"
@@ -18,82 +20,106 @@ type serverSettings struct {
 	WriteTimeout time.Duration
 }
 type settings struct {
-	GeodbPath     geodbPath
-	TemplatePath  string
-	BindAddress   string
-	TLSAddress    string
-	TLSCrtPath    string
-	TLSKeyPath    string
-	TrustedHeader string
-	Server        serverSettings
+	GeodbPath           geodbPath
+	TemplatePath        string
+	BindAddress         string
+	TLSAddress          string
+	TLSCrtPath          string
+	TLSKeyPath          string
+	TrustedHeader       string
+	TrustedPortHeader   string
+	EnableSecureHeaders bool
+	Server              serverSettings
+	version             bool
 }
 
 const defaultAddress = ":8080"
 
-var App *settings
+// ErrVersion is the custom error triggered when -version flag is passed
+var ErrVersion = errors.New("setting: version requested")
 
-func Setup() {
-	city := flag.String("geoip2-city", "", "Path to GeoIP2 city database")
-	asn := flag.String("geoip2-asn", "", "Path to GeoIP2 ASN database")
-	template := flag.String("template", "", "Path to template file")
-	address := flag.String(
+// App is the var with the parsed settings
+var App = settings{
+	// hard-coded for the time being
+	Server: serverSettings{
+		ReadTimeout:  10 * time.Second,
+		WriteTimeout: 10 * time.Second,
+	},
+}
+
+// Setup initializes the App object parsing the flags
+func Setup(args []string) (output string, err error) {
+	flags := flag.NewFlagSet("whatismyip", flag.ContinueOnError)
+	var buf bytes.Buffer
+	flags.SetOutput(&buf)
+
+	flags.StringVar(&App.GeodbPath.City, "geoip2-city", "", "Path to GeoIP2 city database")
+	flags.StringVar(&App.GeodbPath.ASN, "geoip2-asn", "", "Path to GeoIP2 ASN database")
+	flags.StringVar(&App.TemplatePath, "template", "", "Path to template file")
+	flags.StringVar(
+		&App.BindAddress,
 		"bind",
 		defaultAddress,
 		"Listening address (see https://pkg.go.dev/net?#Listen)",
 	)
-	addressTLS := flag.String(
+	flags.StringVar(
+		&App.TLSAddress,
 		"tls-bind",
 		"",
 		"Listening address for TLS (see https://pkg.go.dev/net?#Listen)",
 	)
-	tlsCrtPath := flag.String("tls-crt", "", "When using TLS, path to certificate file")
-	tlsKeyPath := flag.String("tls-key", "", "When using TLS, path to private key file")
-	trustedHeader := flag.String(
+	flags.StringVar(&App.TLSCrtPath, "tls-crt", "", "When using TLS, path to certificate file")
+	flags.StringVar(&App.TLSKeyPath, "tls-key", "", "When using TLS, path to private key file")
+	flags.StringVar(
+		&App.TrustedHeader,
 		"trusted-header",
 		"",
-		"Trusted request header for remote IP (e.g. X-Real-IP)",
+		"Trusted request header for remote IP (e.g. X-Real-IP). When using this feature if -trusted-port-header is not set the client port is shown as 'unknown'",
+	)
+	flags.StringVar(
+		&App.TrustedPortHeader,
+		"trusted-port-header",
+		"",
+		"Trusted request header for remote client port (e.g. X-Real-Port). When this parameter is set -trusted-header becomes mandatory",
+	)
+	flags.BoolVar(&App.version, "version", false, "Output version information and exit")
+	flags.BoolVar(
+		&App.EnableSecureHeaders,
+		"enable-secure-headers",
+		false,
+		"Add sane security-related headers to every response",
 	)
-	ver := flag.Bool("version", false, "Output version information and exit")
 
-	flag.Parse()
-
-	if *ver {
-		fmt.Printf("whatismyip version %s", core.Version)
-		os.Exit(0)
+	err = flags.Parse(args)
+	if err != nil {
+		return buf.String(), err
 	}
 
-	if *city == "" || *asn == "" {
-		exitWithError("geoip2-city and geoip2-asn parameters are mandatory")
+	if App.version {
+		return fmt.Sprintf("whatismyip version %s", core.Version), ErrVersion
 	}
 
-	if (*addressTLS != "") && (*tlsCrtPath == "" || *tlsKeyPath == "") {
-		exitWithError("In order to use TLS -tls-crt and -tls-key flags are mandatory")
+	if App.TrustedPortHeader != "" && App.TrustedHeader == "" {
+		return "", fmt.Errorf("truster-header is mandatory when truster-port-header is set\n")
 	}
 
-	if *template != "" {
-		info, err := os.Stat(*template)
-		if os.IsNotExist(err) || info.IsDir() {
-			exitWithError(*template + " doesn't exist or it's not a file")
+	if App.GeodbPath.City == "" || App.GeodbPath.ASN == "" {
+		return "", fmt.Errorf("geoip2-city and geoip2-asn parameters are mandatory\n")
+	}
+
+	if (App.TLSAddress != "") && (App.TLSCrtPath == "" || App.TLSKeyPath == "") {
+		return "", fmt.Errorf("In order to use TLS -tls-crt and -tls-key flags are mandatory\n")
+	}
+
+	if App.TemplatePath != "" {
+		info, err := os.Stat(App.TemplatePath)
+		if os.IsNotExist(err) {
+			return "", fmt.Errorf("%s no such file or directory\n", App.TemplatePath)
+		}
+		if info.IsDir() {
+			return "", fmt.Errorf("%s must be a file\n", App.TemplatePath)
 		}
 	}
 
-	App = &settings{
-		GeodbPath:     geodbPath{City: *city, ASN: *asn},
-		TemplatePath:  *template,
-		BindAddress:   *address,
-		TLSAddress:    *addressTLS,
-		TLSCrtPath:    *tlsCrtPath,
-		TLSKeyPath:    *tlsKeyPath,
-		TrustedHeader: *trustedHeader,
-		Server: serverSettings{
-			ReadTimeout:  10 * time.Second,
-			WriteTimeout: 10 * time.Second,
-		},
-	}
-}
-
-func exitWithError(error string) {
-	fmt.Printf("%s\n\n", error)
-	flag.Usage()
-	os.Exit(1)
+	return buf.String(), nil
 }

internal/setting/app_test.go

@@ -0,0 +1,197 @@
+package setting
+
+import (
+	"flag"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseMandatoryFlags(t *testing.T) {
+	var mandatoryFlags = []struct {
+		args []string
+	}{
+		{
+			[]string{},
+		},
+		{
+			[]string{"-geoip2-city", "/city-path"},
+		},
+		{
+			[]string{"-geoip2-asn", "/asn-path"},
+		},
+		{
+			[]string{
+				"-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path", "-tls-bind", ":9000",
+			},
+		},
+		{
+			[]string{
+				"-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path", "-tls-bind", ":9000",
+				"-tls-crt", "/crt-path",
+			},
+		},
+		{
+			[]string{
+				"-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path", "-tls-bind", ":9000",
+				"-tls-key", "/key-path",
+			},
+		},
+		{
+			[]string{
+				"-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path", "-bind", ":8000",
+				"-trusted-port-header", "port-header",
+			},
+		},
+	}
+
+	for _, tt := range mandatoryFlags {
+		t.Run(strings.Join(tt.args, " "), func(t *testing.T) {
+			_, err := Setup(tt.args)
+			require.NotNil(t, err)
+			assert.Contains(t, err.Error(), "mandatory")
+		})
+	}
+}
+
+func TestParseFlags(t *testing.T) {
+	var flags = []struct {
+		args []string
+		conf settings
+	}{
+		{
+			[]string{"-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path"},
+			settings{
+				GeodbPath: geodbPath{
+					City: "/city-path",
+					ASN:  "/asn-path",
+				},
+				BindAddress: ":8080",
+				Server: serverSettings{
+					ReadTimeout:  10 * time.Second,
+					WriteTimeout: 10 * time.Second,
+				},
+			},
+		},
+		{
+			[]string{"-bind", ":8001", "-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path"},
+			settings{
+				GeodbPath: geodbPath{
+					City: "/city-path",
+					ASN:  "/asn-path",
+				},
+				BindAddress: ":8001",
+				Server: serverSettings{
+					ReadTimeout:  10 * time.Second,
+					WriteTimeout: 10 * time.Second,
+				},
+			},
+		},
+		{
+			[]string{
+				"-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path", "-tls-bind", ":9000",
+				"-tls-crt", "/crt-path", "-tls-key", "/key-path",
+			},
+			settings{
+				GeodbPath: geodbPath{
+					City: "/city-path",
+					ASN:  "/asn-path",
+				},
+				BindAddress: ":8080",
+				TLSAddress:  ":9000",
+				TLSCrtPath:  "/crt-path",
+				TLSKeyPath:  "/key-path",
+				Server: serverSettings{
+					ReadTimeout:  10 * time.Second,
+					WriteTimeout: 10 * time.Second,
+				},
+			},
+		},
+		{
+			[]string{
+				"-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path",
+				"-trusted-header", "header", "-trusted-port-header", "port-header",
+			},
+			settings{
+				GeodbPath: geodbPath{
+					City: "/city-path",
+					ASN:  "/asn-path",
+				},
+				BindAddress:       ":8080",
+				TrustedHeader:     "header",
+				TrustedPortHeader: "port-header",
+				Server: serverSettings{
+					ReadTimeout:  10 * time.Second,
+					WriteTimeout: 10 * time.Second,
+				},
+			},
+		},
+		{
+			[]string{
+				"-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path",
+				"-trusted-header", "header", "-enable-secure-headers",
+			},
+			settings{
+				GeodbPath: geodbPath{
+					City: "/city-path",
+					ASN:  "/asn-path",
+				},
+				BindAddress:         ":8080",
+				TrustedHeader:       "header",
+				EnableSecureHeaders: true,
+				Server: serverSettings{
+					ReadTimeout:  10 * time.Second,
+					WriteTimeout: 10 * time.Second,
+				},
+			},
+		},
+	}
+
+	for _, tt := range flags {
+		t.Run(strings.Join(tt.args, " "), func(t *testing.T) {
+			_, err := Setup(tt.args)
+			require.Nil(t, err)
+			assert.True(t, reflect.DeepEqual(App, tt.conf))
+		})
+	}
+}
+
+func TestParseFlagsUsage(t *testing.T) {
+	var usageArgs = []string{"-help", "-h", "--help"}
+
+	for _, arg := range usageArgs {
+		t.Run(arg, func(t *testing.T) {
+			output, err := Setup([]string{arg})
+			assert.ErrorIs(t, err, flag.ErrHelp)
+			assert.Contains(t, output, "Usage of")
+		})
+	}
+}
+
+func TestParseFlagVersion(t *testing.T) {
+	output, err := Setup([]string{"-version"})
+	assert.ErrorIs(t, err, ErrVersion)
+	assert.Contains(t, output, "whatismyip version")
+}
+
+func TestParseFlagTemplate(t *testing.T) {
+	flags := []string{
+		"-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path",
+		"-template", "/template-path",
+	}
+	_, err := Setup(flags)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "no such file or directory")
+
+	flags = []string{
+		"-geoip2-city", "/city-path", "-geoip2-asn", "/asn-path",
+		"-template", "/",
+	}
+	_, err = Setup(flags)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "must be a file")
+}

models/geo.go

@@ -7,10 +7,7 @@ import (
 	"github.com/oschwald/maxminddb-golang"
 )
 
-type Record interface {
-	LookUp(ip net.IP)
-}
-
+// GeoRecord is the model for City database
 type GeoRecord struct {
 	Country struct {
 		ISOCode string            `maxminddb:"iso_code"`
@@ -29,6 +26,7 @@ type GeoRecord struct {
 	} `maxminddb:"postal"`
 }
 
+// ASNRecord is the model for ASN database
 type ASNRecord struct {
 	AutonomousSystemNumber       uint   `maxminddb:"autonomous_system_number"`
 	AutonomousSystemOrganization string `maxminddb:"autonomous_system_organization"`
@@ -51,11 +49,13 @@ func openMMDB(path string) *maxminddb.Reader {
 	return db
 }
 
+// Setup opens all Geolite2 databases
 func Setup(cityPath string, asnPath string) {
 	db.city = openMMDB(cityPath)
 	db.asn = openMMDB(asnPath)
 }
 
+// CloseDBs unmaps from memory and frees resources to the filesystem
 func CloseDBs() {
 	log.Printf("Closing dbs...")
 	if err := db.city.Close(); err != nil {
@@ -66,20 +66,12 @@ func CloseDBs() {
 	}
 }
 
+// LookUp an IP and get city data
 func (record *GeoRecord) LookUp(ip net.IP) error {
-	err := db.city.Lookup(ip, record)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return db.city.Lookup(ip, record)
 }
 
+// LookUp an IP and get ASN data
 func (record *ASNRecord) LookUp(ip net.IP) error {
-	err := db.asn.Lookup(ip, record)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return db.asn.Lookup(ip, record)
 }

models/geo_test.go

@@ -0,0 +1,77 @@
+package models
+
+import (
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestModels(t *testing.T) {
+	expectedCity := &GeoRecord{
+		Country: struct {
+			ISOCode string            "maxminddb:\"iso_code\""
+			Names   map[string]string "maxminddb:\"names\""
+		}{
+			ISOCode: "GB",
+			Names: map[string]string{
+				"de":    "Vereinigtes Königreich",
+				"en":    "United Kingdom",
+				"es":    "Reino Unido",
+				"fr":    "Royaume-Uni",
+				"ja":    "イギリス",
+				"pt-BR": "Reino Unido",
+				"ru":    "Великобритания",
+				"zh-CN": "英国",
+			},
+		},
+		City: struct {
+			Names map[string]string "maxminddb:\"names\""
+		}{
+			Names: map[string]string{
+				"de":    "London",
+				"en":    "London",
+				"es":    "Londres",
+				"fr":    "Londres",
+				"ja":    "ロンドン",
+				"pt-BR": "Londres",
+				"ru":    "Лондон",
+			},
+		},
+		Location: struct {
+			Latitude  float64 "maxminddb:\"latitude\""
+			Longitude float64 "maxminddb:\"longitude\""
+			TimeZone  string  "maxminddb:\"time_zone\""
+		}{
+			Latitude:  51.5142,
+			Longitude: -0.0931,
+			TimeZone:  "Europe/London",
+		},
+		Postal: struct {
+			Code string "maxminddb:\"code\""
+		}{
+			Code: "",
+		},
+	}
+
+	expectedASN := &ASNRecord{
+		AutonomousSystemNumber:       12552,
+		AutonomousSystemOrganization: "IP-Only",
+	}
+
+	Setup("../test/GeoIP2-City-Test.mmdb", "../test/GeoLite2-ASN-Test.mmdb")
+	defer CloseDBs()
+
+	assert.NotNil(t, db.asn)
+	assert.NotNil(t, db.city)
+
+	cityRecord := &GeoRecord{}
+	assert.Nil(t, cityRecord.LookUp(net.ParseIP("81.2.69.192")))
+	assert.Equal(t, expectedCity, cityRecord)
+	assert.Error(t, cityRecord.LookUp(net.ParseIP("error")))
+
+	asnRecord := &ASNRecord{}
+	assert.Nil(t, asnRecord.LookUp(net.ParseIP("82.99.17.64")))
+	assert.Equal(t, expectedASN, asnRecord)
+	assert.Error(t, asnRecord.LookUp(net.ParseIP("error")))
+}

router/generic.go

@@ -4,7 +4,6 @@ import (
 	"net"
 	"net/http"
 	"path/filepath"
-	"regexp"
 
 	"github.com/dcarrillo/whatismyip/internal/httputils"
 	"github.com/dcarrillo/whatismyip/internal/setting"
@@ -12,8 +11,7 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-const userAgentPattern = `curl|wget|libwww-perl|python|ansible-httpget|HTTPie|WindowsPowerShell|http_request|Go-http-client|^$`
-
+// JSONResponse maps data as json
 type JSONResponse struct {
 	IP              string      `json:"ip"`
 	IPVersion       byte        `json:"ip_version"`
@@ -32,27 +30,45 @@ type JSONResponse struct {
 }
 
 func getRoot(ctx *gin.Context) {
-	reg := regexp.MustCompile(userAgentPattern)
-	if reg.Match([]byte(ctx.Request.UserAgent())) {
-		ctx.String(http.StatusOK, ctx.ClientIP())
-	} else {
+	switch ctx.NegotiateFormat(gin.MIMEPlain, gin.MIMEHTML, gin.MIMEJSON) {
+	case gin.MIMEHTML:
 		name := "home"
 		if setting.App.TemplatePath != "" {
 			name = filepath.Base(setting.App.TemplatePath)
 		}
 		ctx.HTML(http.StatusOK, name, jsonOutput(ctx))
+	case gin.MIMEJSON:
+		getJSON(ctx)
+	default:
+		ctx.String(http.StatusOK, ctx.ClientIP()+"\n")
 	}
 }
 
+func getClientPort(ctx *gin.Context) string {
+	var port string
+	if setting.App.TrustedPortHeader == "" {
+		if setting.App.TrustedHeader != "" {
+			port = "unknown"
+		} else {
+			_, port, _ = net.SplitHostPort(ctx.Request.RemoteAddr)
+		}
+	} else {
+		port = ctx.GetHeader(setting.App.TrustedPortHeader)
+		if port == "" {
+			port = "unknown"
+		}
+	}
+
+	return port
+}
+
 func getClientPortAsString(ctx *gin.Context) {
-	_, port, _ := net.SplitHostPort(ctx.Request.RemoteAddr)
-	ctx.String(http.StatusOK, port+"\n")
+	ctx.String(http.StatusOK, getClientPort(ctx)+"\n")
 }
 
 func getAllAsString(ctx *gin.Context) {
 	output := "IP: " + ctx.ClientIP() + "\n"
-	_, port, _ := net.SplitHostPort(ctx.Request.RemoteAddr)
-	output += "Client Port: " + port + "\n"
+	output += "Client Port: " + getClientPort(ctx) + "\n"
 
 	r := service.Geo{IP: net.ParseIP(ctx.ClientIP())}
 	if record := r.LookUpCity(); record != nil {
@@ -63,8 +79,8 @@ func getAllAsString(ctx *gin.Context) {
 		output += geoASNRecordToString(record) + "\n"
 	}
 
-	h := ctx.Request.Header
-	h["Host"] = []string{ctx.Request.Host}
+	h := httputils.GetHeadersWithoutTrustedHeaders(ctx)
+	h.Set("Host", ctx.Request.Host)
 	output += httputils.HeadersToSortedString(h)
 
 	ctx.String(http.StatusOK, output)
@@ -83,11 +99,10 @@ func jsonOutput(ctx *gin.Context) JSONResponse {
 		version = 6
 	}
 
-	_, port, _ := net.SplitHostPort(ctx.Request.RemoteAddr)
 	return JSONResponse{
 		IP:              ctx.ClientIP(),
 		IPVersion:       version,
-		ClientPort:      port,
+		ClientPort:      getClientPort(ctx),
 		Country:         cityRecord.Country.Names["en"],
 		CountryCode:     cityRecord.Country.ISOCode,
 		City:            cityRecord.City.Names["en"],
@@ -98,6 +113,6 @@ func jsonOutput(ctx *gin.Context) JSONResponse {
 		ASN:             asnRecord.AutonomousSystemNumber,
 		ASNOrganization: asnRecord.AutonomousSystemOrganization,
 		Host:            ctx.Request.Host,
-		Headers:         ctx.Request.Header,
+		Headers:         httputils.GetHeadersWithoutTrustedHeaders(ctx),
 	}
 }

router/generic_test.go

@@ -6,34 +6,84 @@ import (
 	"net/http/httptest"
 	"testing"
 
+	"github.com/dcarrillo/whatismyip/internal/setting"
 	"github.com/stretchr/testify/assert"
 )
 
-func TestIP4RootFromCli(t *testing.T) {
-	uas := []string{
-		"",
-		"curl",
-		"wget",
-		"libwww-perl",
-		"python",
-		"ansible-httpget",
-		"HTTPie",
-		"WindowsPowerShell",
-		"http_request",
-		"Go-http-client",
+func TestRootContentType(t *testing.T) {
+	tests := []struct {
+		name     string
+		accepted string
+		expected string
+	}{
+		{
+			name:     "Accept wildcard",
+			accepted: "*/*",
+			expected: contentType.text,
+		},
+		{
+			name:     "Bogus accept",
+			accepted: "bogus/plain",
+			expected: contentType.text,
+		},
+		{
+			name:     "Accept plain text",
+			accepted: "text/plain",
+			expected: contentType.text,
+		},
+		{
+			name:     "Accept json",
+			accepted: "application/json",
+			expected: contentType.json,
+		},
 	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req, _ := http.NewRequest("GET", "/", nil)
+			req.Header.Set(trustedHeader, testIP.ipv4)
+			req.Header.Set("Accept", tt.accepted)
 
-	req, _ := http.NewRequest("GET", "/", nil)
-	req.Header.Set("X-Real-IP", testIP.ipv4)
+			w := httptest.NewRecorder()
+			app.ServeHTTP(w, req)
 
-	for _, ua := range uas {
-		req.Header.Set("User-Agent", ua)
+			assert.Equal(t, 200, w.Code)
+			assert.Equal(t, tt.expected, w.Header().Get("Content-Type"))
+		})
+	}
+}
 
-		w := httptest.NewRecorder()
-		app.ServeHTTP(w, req)
+func TestGetIP(t *testing.T) {
+	expected := testIP.ipv4 + "\n"
+	tests := []struct {
+		name     string
+		accepted string
+	}{
+		{
+			name:     "No browser",
+			accepted: "*/*",
+		},
+		{
+			name:     "Bogus accept",
+			accepted: "bogus/plain",
+		},
+		{
+			name:     "Plain accept",
+			accepted: "text/plain",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req, _ := http.NewRequest("GET", "/", nil)
+			req.Header.Set(trustedHeader, testIP.ipv4)
+			req.Header.Set("Accept", tt.accepted)
 
-		assert.Equal(t, 200, w.Code)
-		assert.Equal(t, testIP.ipv4, w.Body.String())
+			w := httptest.NewRecorder()
+			app.ServeHTTP(w, req)
+
+			assert.Equal(t, 200, w.Code)
+			assert.Equal(t, expected, w.Body.String())
+			assert.Equal(t, contentType.text, w.Header().Get("Content-Type"))
+		})
 	}
 }
 
@@ -48,16 +98,76 @@ func TestHost(t *testing.T) {
 }
 
 func TestClientPort(t *testing.T) {
-	req, _ := http.NewRequest("GET", "/client-port", nil)
-	req.RemoteAddr = net.JoinHostPort(testIP.ipv4 , "1000")
-	req.Header.Set("X-Real-IP", testIP.ipv4)
+	type args struct {
+		params  []string
+		headers map[string][]string
+	}
+	tests := []struct {
+		name     string
+		args     args
+		expected string
+	}{
+		{
+			name:     "No trusted headers set",
+			expected: "1000\n",
+		},
+		{
+			name: "Trusted header only set",
+			args: args{
+				params: []string{
+					"-geoip2-city", "city",
+					"-geoip2-asn", "asn",
+					"-trusted-header", trustedHeader,
+				},
+			},
+			expected: "unknown\n",
+		},
+		{
+			name: "Trusted and port header set but not included in headers",
+			args: args{
+				params: []string{
+					"-geoip2-city", "city",
+					"-geoip2-asn", "asn",
+					"-trusted-header", trustedHeader,
+					"-trusted-port-header", trustedPortHeader,
+				},
+			},
+			expected: "unknown\n",
+		},
+		{
+			name: "Trusted and port header set and included in headers",
+			args: args{
+				params: []string{
+					"-geoip2-city", "city",
+					"-geoip2-asn", "asn",
+					"-trusted-header", trustedHeader,
+					"-trusted-port-header", trustedPortHeader,
+				},
+				headers: map[string][]string{
+					trustedHeader:     {testIP.ipv4},
+					trustedPortHeader: {"1001"},
+				},
+			},
+			expected: "1001\n",
+		},
+	}
 
-	w := httptest.NewRecorder()
-	app.ServeHTTP(w, req)
+	for _, tt := range tests {
+		_, _ = setting.Setup(tt.args.params)
+		t.Run(tt.name, func(t *testing.T) {
+			req, _ := http.NewRequest("GET", "/client-port", nil)
+			req.RemoteAddr = net.JoinHostPort(testIP.ipv4, "1000")
+			req.Header = tt.args.headers
 
-	assert.Equal(t, 200, w.Code)
-	assert.Equal(t, contentType.text, w.Header().Get("Content-Type"))
-	assert.Equal(t, "1000\n", w.Body.String())
+			w := httptest.NewRecorder()
+			app.ServeHTTP(w, req)
+
+			assert.Equal(t, 200, w.Code)
+			assert.Equal(t, contentType.text, w.Header().Get("Content-Type"))
+			assert.Equal(t, tt.expected, w.Body.String())
+			t.Log(w.Header())
+		})
+	}
 }
 
 func TestNotFound(t *testing.T) {
@@ -71,36 +181,59 @@ func TestNotFound(t *testing.T) {
 }
 
 func TestJSON(t *testing.T) {
-	expectedIPv4 := `{"client_port":"1000","ip":"81.2.69.192","ip_version":4,"country":"United Kingdom","country_code":"GB","city":"London","latitude":51.5142,"longitude":-0.0931,"postal_code":"","time_zone":"Europe/London","asn":0,"asn_organization":"","host":"test","headers":{"X-Real-Ip":["81.2.69.192"]}}`
-	expectedIPv6 := `{"asn":3352, "asn_organization":"TELEFONICA DE ESPANA", "city":"", "client_port":"1000", "country":"", "country_code":"", "headers":{"X-Real-Ip":["2a02:9000::1"]}, "host":"test", "ip":"2a02:9000::1", "ip_version":6, "latitude":0, "longitude":0, "postal_code":"", "time_zone":""}`
+	_, _ = setting.Setup(
+		[]string{
+			"-geoip2-city", "city",
+			"-geoip2-asn", "asn",
+			"-trusted-header", trustedHeader,
+			"-trusted-port-header", trustedPortHeader,
+		},
+	)
 
-	req, _ := http.NewRequest("GET", "/json", nil)
-	req.RemoteAddr = net.JoinHostPort(testIP.ipv4, "1000")
-	req.Host = "test"
-	req.Header.Set("X-Real-IP", testIP.ipv4)
+	type args struct {
+		ip string
+	}
+	tests := []struct {
+		name     string
+		args     args
+		expected string
+	}{
+		{
+			name: "IPv4",
+			args: args{
+				ip: testIP.ipv4,
+			},
+			expected: jsonIPv4,
+		},
+		{
+			name: "IPv6",
+			args: args{
+				ip: testIP.ipv6,
+			},
+			expected: jsonIPv6,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req, _ := http.NewRequest("GET", "/json", nil)
+			req.RemoteAddr = net.JoinHostPort(tt.args.ip, "1000")
+			req.Host = "test"
+			req.Header.Set(trustedHeader, tt.args.ip)
+			req.Header.Set(trustedPortHeader, "1001")
 
-	w := httptest.NewRecorder()
-	app.ServeHTTP(w, req)
+			w := httptest.NewRecorder()
+			app.ServeHTTP(w, req)
 
-	assert.Equal(t, 200, w.Code)
-	assert.Equal(t, contentType.json, w.Header().Get("Content-Type"))
-	assert.JSONEq(t, expectedIPv4, w.Body.String())
-
-	req.RemoteAddr = net.JoinHostPort(testIP.ipv6, "1000")
-	req.Host = "test"
-	req.Header.Set("X-Real-IP", testIP.ipv6)
-
-	w = httptest.NewRecorder()
-	app.ServeHTTP(w, req)
-
-	assert.Equal(t, 200, w.Code)
-	assert.Equal(t, contentType.json, w.Header().Get("Content-Type"))
-	assert.JSONEq(t, expectedIPv6, w.Body.String())
+			assert.Equal(t, 200, w.Code)
+			assert.Equal(t, contentType.json, w.Header().Get("Content-Type"))
+			assert.JSONEq(t, tt.expected, w.Body.String())
+		})
+	}
 }
 
 func TestAll(t *testing.T) {
 	expected := `IP: 81.2.69.192
-Client Port: 1000
+Client Port: 1001
 City: London
 Country: United Kingdom
 Country Code: GB
@@ -114,13 +247,21 @@ ASN Organization:
 
 Header1: one
 Host: test
-X-Real-Ip: 81.2.69.192
 `
+	_, _ = setting.Setup(
+		[]string{
+			"-geoip2-city", "city",
+			"-geoip2-asn", "asn",
+			"-trusted-header", trustedHeader,
+			"-trusted-port-header", trustedPortHeader,
+		},
+	)
 
 	req, _ := http.NewRequest("GET", "/all", nil)
-	req.RemoteAddr = net.JoinHostPort(testIP.ipv4 , "1000")
+	req.RemoteAddr = net.JoinHostPort(testIP.ipv4, "1000")
 	req.Host = "test"
-	req.Header.Set("X-Real-IP", testIP.ipv4)
+	req.Header.Set(trustedHeader, testIP.ipv4)
+	req.Header.Set(trustedPortHeader, "1001")
 	req.Header.Set("Header1", "one")
 
 	w := httptest.NewRecorder()

router/headers.go

@@ -10,15 +10,17 @@ import (
 )
 
 func getHeadersAsSortedString(ctx *gin.Context) {
-	h := ctx.Request.Header
-	h["Host"] = []string{ctx.Request.Host}
+	h := httputils.GetHeadersWithoutTrustedHeaders(ctx)
+	h.Set("Host", ctx.Request.Host)
 
 	ctx.String(http.StatusOK, httputils.HeadersToSortedString(h))
 }
 
 func getHeaderAsString(ctx *gin.Context) {
+	headers := httputils.GetHeadersWithoutTrustedHeaders(ctx)
+
 	h := ctx.Params.ByName("header")
-	if v := ctx.GetHeader(h); v != "" {
+	if v := headers.Get(ctx.Params.ByName("header")); v != "" {
 		ctx.String(http.StatusOK, template.HTMLEscapeString(v))
 	} else if strings.ToLower(h) == "host" {
 		ctx.String(http.StatusOK, template.HTMLEscapeString(ctx.Request.Host))

router/headers_test.go

@@ -5,6 +5,7 @@ import (
 	"net/http/httptest"
 	"testing"
 
+	"github.com/dcarrillo/whatismyip/internal/setting"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -26,11 +27,20 @@ Header2: value22
 Header3: value3
 Host: 
 `
-
+	_, _ = setting.Setup([]string{
+		"-geoip2-city", "city",
+		"-geoip2-asn", "asn",
+		"-trusted-header", trustedHeader,
+		"-trusted-port-header", trustedPortHeader,
+	})
 	req, _ := http.NewRequest("GET", "/headers", nil)
-	req.Header["Header1"] = []string{"value1"}
-	req.Header["Header2"] = []string{"value21", "value22"}
-	req.Header["Header3"] = []string{"value3"}
+	req.Header = map[string][]string{
+		"Header1": {"value1"},
+		"Header2": {"value21", "value22"},
+		"Header3": {"value3"},
+	}
+	req.Header.Set(trustedHeader, "1.1.1.1")
+	req.Header.Set(trustedPortHeader, "1025")
 
 	w := httptest.NewRecorder()
 	app.ServeHTTP(w, req)

router/setup.go

@@ -8,6 +8,7 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
+// SetupTemplate reads and parses a template from file
 func SetupTemplate(r *gin.Engine) {
 	if setting.App.TemplatePath == "" {
 		t, _ := template.New("home").Parse(home)
@@ -18,6 +19,7 @@ func SetupTemplate(r *gin.Engine) {
 	}
 }
 
+// Setup defines the endpoints
 func Setup(r *gin.Engine) {
 	r.GET("/", getRoot)
 	r.GET("/client-port", getClientPortAsString)

router/setup_test.go

@@ -16,6 +16,7 @@ type testIPs struct {
 }
 
 type contentTypes struct {
+	html string
 	text string
 	json string
 }
@@ -29,12 +30,16 @@ var (
 		ipv6ASN: "2a02:a800::1",
 	}
 	contentType = contentTypes{
+		html: "content-type: text/html; charset=utf-8",
 		text: "text/plain; charset=utf-8",
 		json: "application/json; charset=utf-8",
 	}
+	jsonIPv4 = `{"client_port":"1001","ip":"81.2.69.192","ip_version":4,"country":"United Kingdom","country_code":"GB","city":"London","latitude":51.5142,"longitude":-0.0931,"postal_code":"","time_zone":"Europe/London","asn":0,"asn_organization":"","host":"test", "headers": {}}`
+	jsonIPv6 = `{"asn":3352, "asn_organization":"TELEFONICA DE ESPANA", "city":"", "client_port":"1001", "country":"", "country_code":"", "host":"test", "ip":"2a02:9000::1", "ip_version":6, "latitude":0, "longitude":0, "postal_code":"", "time_zone":"", "headers": {}}`
 )
 
 const trustedHeader = "X-Real-IP"
+const trustedPortHeader = "X-Real-Port"
 
 func TestMain(m *testing.M) {
 	app = gin.Default()

router/templates_test.go

@@ -54,10 +54,11 @@ const expectedHome = `
 
 func TestDefaultTemplate(t *testing.T) {
 	req, _ := http.NewRequest("GET", "/", nil)
-
-	req.Header["Header1"] = []string{"value1"}
-	req.Header["Header2"] = []string{"value21", "value22"}
-	req.Header["Header3"] = []string{"value3"}
+	req.Header = map[string][]string{
+		"Header1": {"value1"},
+		"Header2": {"value21", "value22"},
+		"Header3": {"value3"},
+	}
 
 	tmpl, _ := template.New("home").Parse(home)
 	response := JSONResponse{

service/geo.go

@@ -7,10 +7,12 @@ import (
 	"github.com/dcarrillo/whatismyip/models"
 )
 
+// Geo defines a base type for lookups
 type Geo struct {
 	IP net.IP
 }
 
+// LookUpCity queries the database for city data related to the given IP
 func (g *Geo) LookUpCity() *models.GeoRecord {
 	record := &models.GeoRecord{}
 	err := record.LookUp(g.IP)
@@ -22,6 +24,7 @@ func (g *Geo) LookUpCity() *models.GeoRecord {
 	return record
 }
 
+// LookUpASN queries the database for ASN data related to the given IP
 func (g *Geo) LookUpASN() *models.ASNRecord {
 	record := &models.ASNRecord{}
 	err := record.LookUp(g.IP)