Add an artifacts proxy to GitLab Pages

author: J. Shuster <joshuagregoryshuster@gmail.com> 2017-09-08 11:58:42 +0300
committer: Nick Thomas <nick@gitlab.com> 2017-09-08 11:58:42 +0300
commit: 0a144bc6055b41fac726fdc6eeaa7150f622bd20 (patch)
tree: 9ed2a4dbecbd8146245ae8fa609cd9f54d038bf6
parent: 0173d4e6b6b17443155d121a9098d0e742b9c4e3 (diff)
10 files changed, 851 insertions, 91 deletions
diff --git a/404.go b/404.go
deleted file mode 100644
index 0ac0be54..00000000
--- a/404.go
+++ /dev/null
@@ -1,70 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"net/http"
-)
-
-const predefined404 = `
-<!DOCTYPE html>
-<html>
-  <head>
-    <title>The page you're looking for could not be found (404)</title>
-    <style>
-      body {
-        color: #666;
-        text-align: center;
-        font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
-        margin: 0;
-        width: 800px;
-        margin: auto;
-        font-size: 14px;
-      }
-
-      h1 {
-        font-size: 56px;
-        line-height: 100px;
-        font-weight: normal;
-        color: #456;
-      }
-
-      h2 {
-        font-size: 24px;
-        color: #666;
-        line-height: 1.5em;
-      }
-
-      h3 {
-        color: #456;
-        font-size: 20px;
-        font-weight: normal;
-        line-height: 28px;
-      }
-
-      hr {
-        margin: 18px 0;
-        border: 0;
-        border-top: 1px solid #EEE;
-        border-bottom: 1px solid white;
-      }
-    </style>
-  </head>
-
-  <body>
-    <h1>
-      <img src="data:image/svg+xml;base64,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" /><br />
-      404
-    </h1>
-    <h3>The page you're looking for could not be found.</h3>
-    <hr/>
-    <p>Make sure the address is correct and that the page hasn't moved.</p>
-  </body>
-</html>
-`
-
-func serve404(w http.ResponseWriter) {
-	w.Header().Set("Content-Type", "text/html; charset=utf-8")
-	w.Header().Set("X-Content-Type-Options", "nosniff")
-	w.WriteHeader(http.StatusNotFound)
-	fmt.Fprintln(w, predefined404)
-}
diff --git a/acceptance_test.go b/acceptance_test.go
index 8adef2a6..3e575bdf 100644
--- a/acceptance_test.go
+++ b/acceptance_test.go
@@ -2,10 +2,13 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"io/ioutil"
 	"net/http"
+	"net/http/httptest"
 	"os"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -207,3 +210,97 @@ func TestStatusPage(t *testing.T) {
 	defer rsp.Body.Close()
 	assert.Equal(t, http.StatusOK, rsp.StatusCode)
 }
+
+func TestProxyRequest(t *testing.T) {
+	skipUnlessEnabled(t)
+	content := "<!DOCTYPE html><html><head><title>Title of the document</title></head><body></body></html>"
+	contentLength := int64(len(content))
+	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/projects/1/jobs/2/artifacts/delayed_200.html":
+			time.Sleep(2 * time.Second)
+		case "/projects/1/jobs/2/artifacts/200.html":
+			w.Header().Set("Content-Type", "text/html; charset=utf-8")
+			fmt.Fprint(w, content)
+		case "/projects/1/jobs/2/artifacts/500.html":
+			w.Header().Set("Content-Type", "text/html; charset=utf-8")
+			w.WriteHeader(http.StatusInternalServerError)
+			fmt.Fprint(w, content)
+		default:
+			w.Header().Set("Content-Type", "text/html; charset=utf-8")
+			w.WriteHeader(http.StatusNotFound)
+			fmt.Fprint(w, content)
+		}
+	}))
+	defer testServer.Close()
+	cases := []struct {
+		Path         string
+		Status       int
+		BinaryOption string
+		Content      string
+		Length       int64
+		CacheControl string
+		ContentType  string
+		Description  string
+	}{
+		{
+			"200.html",
+			http.StatusOK,
+			"",
+			content,
+			contentLength,
+			"max-age=3600",
+			"text/html; charset=utf-8",
+			"basic proxied request",
+		},
+		{
+			"delayed_200.html",
+			http.StatusBadGateway,
+			"-artifacts-server-timeout=1",
+			"",
+			0,
+			"",
+			"text/html; charset=utf-8",
+			"502 error while attempting to proxy",
+		},
+		{
+			"404.html",
+			http.StatusNotFound,
+			"",
+			"",
+			0,
+			"",
+			"text/html; charset=utf-8",
+			"Proxying 404 from server",
+		},
+		{
+			"500.html",
+			http.StatusInternalServerError,
+			"",
+			"",
+			0,
+			"",
+			"text/html; charset=utf-8",
+			"Proxying 500 from server",
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(fmt.Sprintf("Proxy Request Test: %s", c.Description), func(t *testing.T) {
+			teardown := RunPagesProcess(t, *pagesBinary, listeners, "", "-artifacts-server="+testServer.URL, c.BinaryOption)
+			defer teardown()
+			resp, err := GetPageFromListener(t, httpListener, "artifact~1~2.gitlab-example.com", c.Path)
+			require.NoError(t, err)
+			defer resp.Body.Close()
+			assert.Equal(t, c.Status, resp.StatusCode)
+			assert.Equal(t, c.ContentType, resp.Header.Get("Content-Type"))
+			if !((c.Status == http.StatusBadGateway) || (c.Status == http.StatusNotFound) || (c.Status == http.StatusInternalServerError)) {
+				body, err := ioutil.ReadAll(resp.Body)
+				require.NoError(t, err)
+				assert.Equal(t, c.Content, string(body))
+				assert.Equal(t, c.Length, resp.ContentLength)
+				assert.Equal(t, c.CacheControl, resp.Header.Get("Cache-Control"))
+			}
+		})
+	}
+}
diff --git a/app.go b/app.go
index 61b1176c..3714582a 100644
--- a/app.go
+++ b/app.go
@@ -14,6 +14,8 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/rs/cors"
 
+	"gitlab.com/gitlab-org/gitlab-pages/internal/artifact"
+	"gitlab.com/gitlab-org/gitlab-pages/internal/httperrors"
 	"gitlab.com/gitlab-org/gitlab-pages/metrics"
 )
 
@@ -26,8 +28,9 @@ var (
 
 type theApp struct {
 	appConfig
-	domains domains
-	lock    sync.RWMutex
+	domains  domains
+	lock     sync.RWMutex
+	Artifact *artifact.Artifact
 }
 
 func (a *theApp) domain(host string) *domain {
@@ -79,9 +82,16 @@ func (a *theApp) serveContent(ww http.ResponseWriter, r *http.Request, https boo
 	if err != nil {
 		host = r.Host
 	}
+
+	// In the event a host is prefixed with the artifact prefix an artifact
+	// value is created, and an attempt to proxy the request is made
+	if a.Artifact.TryMakeRequest(host, &w, r) {
+		return
+	}
+
 	domain := a.domain(host)
 	if domain == nil {
-		serve404(&w)
+		httperrors.Serve404(&w)
 		return
 	}
 
@@ -173,5 +183,9 @@ func (a *theApp) Run() {
 
 func runApp(config appConfig) {
 	a := theApp{appConfig: config}
+
+	if config.ArtifactsServer != "" {
+		a.Artifact = artifact.New(config.ArtifactsServer, config.ArtifactsServerTimeout, config.Domain)
+	}
 	a.Run()
 }
diff --git a/app_config.go b/app_config.go
index e45dda24..dd47ed01 100644
--- a/app_config.go
+++ b/app_config.go
@@ -1,10 +1,11 @@
 package main
 
 type appConfig struct {
-	Domain string
-
-	RootCertificate []byte
-	RootKey         []byte
+	Domain                 string
+	ArtifactsServer        string
+	ArtifactsServerTimeout int
+	RootCertificate        []byte
+	RootKey                []byte
 
 	ListenHTTP    []uintptr
 	ListenHTTPS   []uintptr
diff --git a/domain.go b/domain.go
index 45e59f94..fc6611e1 100644
--- a/domain.go
+++ b/domain.go
@@ -13,6 +13,7 @@ import (
 	"strings"
 	"time"
 
+	"gitlab.com/gitlab-org/gitlab-pages/internal/httperrors"
 	"gitlab.com/gitlab-org/gitlab-pages/internal/httputil"
 )
 
@@ -215,7 +216,7 @@ func (d *domain) serveFromGroup(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Serve generic not found
-	serve404(w)
+	httperrors.Serve404(w)
 }
 
 func (d *domain) serveFromConfig(w http.ResponseWriter, r *http.Request) {
@@ -230,7 +231,7 @@ func (d *domain) serveFromConfig(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Serve generic not found
-	serve404(w)
+	httperrors.Serve404(w)
 }
 
 func (d *domain) ensureCertificate() (*tls.Certificate, error) {
diff --git a/internal/artifact/artifact.go b/internal/artifact/artifact.go
new file mode 100644
index 00000000..bcb525ac
--- /dev/null
+++ b/internal/artifact/artifact.go
@@ -0,0 +1,120 @@
+package artifact
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"gitlab.com/gitlab-org/gitlab-pages/internal/httperrors"
+)
+
+const (
+	baseURL             = "/projects/%s/jobs/%s/artifacts"
+	hostPatternTemplate = `(?i)\Aartifact~(\d+)~(\d+)\.%s\z`
+	minStatusCode       = 200
+	maxStatusCode       = 299
+)
+
+// Artifact is a struct that is made up of a url.URL, http.Client, and
+// regexp.Regexp that is used to proxy requests where applicable.
+type Artifact struct {
+	server  string
+	client  *http.Client
+	pattern *regexp.Regexp
+}
+
+// New when provided the arguments defined herein, returns a pointer to an
+// Artifact that is used to proxy requests.
+func New(s string, timeout int, pagesDomain string) *Artifact {
+	return &Artifact{
+		server:  s,
+		client:  &http.Client{Timeout: time.Second * time.Duration(timeout)},
+		pattern: hostPatternGen(pagesDomain),
+	}
+
+}
+
+// TryMakeRequest will attempt to proxy a request and write it to the argument
+// http.ResponseWriter, ultimately returning a bool that indicates if the
+// http.ResponseWriter has been written to in any capacity.
+func (a *Artifact) TryMakeRequest(host string, w http.ResponseWriter, r *http.Request) bool {
+	if a == nil || a.server == "" {
+		return false
+	}
+
+	reqURL, ok := a.buildURL(host, r.URL.Path)
+	if !ok {
+		return false
+	}
+
+	resp, err := a.client.Get(reqURL.String())
+	if err != nil {
+		httperrors.Serve502(w)
+		return true
+	}
+
+	if resp.StatusCode == http.StatusNotFound {
+		httperrors.Serve404(w)
+		return true
+	}
+
+	if resp.StatusCode == http.StatusInternalServerError {
+		httperrors.Serve500(w)
+		return true
+	}
+
+	// we only cache responses within the 2xx series response codes
+	if (resp.StatusCode >= minStatusCode) && (resp.StatusCode <= maxStatusCode) {
+		w.Header().Set("Cache-Control", "max-age=3600")
+	}
+
+	w.Header().Set("Content-Type", resp.Header.Get("Content-Type"))
+	w.Header().Set("Content-Length", strconv.FormatInt(resp.ContentLength, 10))
+	w.WriteHeader(resp.StatusCode)
+	io.Copy(w, resp.Body)
+	return true
+}
+
+// buildURL returns a pointer to a url.URL for where the request should be
+// proxied to. The returned bool will indicate if there is some sort of issue
+// with the url while it is being generated.
+func (a *Artifact) buildURL(host, path string) (*url.URL, bool) {
+	ids := a.pattern.FindAllStringSubmatch(host, -1)
+	if len(ids) != 1 || len(ids[0]) != 3 {
+		return nil, false
+	}
+
+	strippedIds := ids[0][1:3]
+	body := fmt.Sprintf(baseURL, strippedIds[0], strippedIds[1])
+	ourPath := a.server
+	if strings.HasSuffix(ourPath, "/") {
+		ourPath = ourPath[0:len(ourPath)-1] + body
+	} else {
+		ourPath = ourPath + body
+	}
+
+	if len(path) == 0 || strings.HasPrefix(path, "/") {
+		ourPath = ourPath + path
+	} else {
+		ourPath = ourPath + "/" + path
+	}
+
+	u, err := url.Parse(ourPath)
+	if err != nil {
+		return nil, false
+	}
+	return u, true
+}
+
+// hostPatternGen returns a pointer to a regexp.Regexp that is made up of
+// the constant hostPatternTemplate and the argument which represents the pages domain.
+// This is used to ensure that the requested page meets not only the hostPatternTemplate
+// requirements, but is suffixed with the proper pagesDomain.
+func hostPatternGen(pagesDomain string) *regexp.Regexp {
+	return regexp.MustCompile(fmt.Sprintf(hostPatternTemplate, regexp.QuoteMeta(pagesDomain)))
+}
diff --git a/internal/artifact/artifact_test.go b/internal/artifact/artifact_test.go
new file mode 100644
index 00000000..ad2285f6
--- /dev/null
+++ b/internal/artifact/artifact_test.go
@@ -0,0 +1,303 @@
+package artifact
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"regexp"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTryMakeRequest(t *testing.T) {
+	content := "<!DOCTYPE html><html><head><title>Title of the document</title></head><body></body></html>"
+	contentType := "text/html; charset=utf-8"
+	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", contentType)
+		switch r.URL.Path {
+		case "/projects/1/jobs/2/artifacts/200.html":
+			w.WriteHeader(http.StatusOK)
+		case "/projects/1/jobs/2/artifacts/max-caching.html":
+			w.WriteHeader(http.StatusIMUsed)
+		case "/projects/1/jobs/2/artifacts/non-caching.html":
+			w.WriteHeader(http.StatusTeapot)
+		case "/projects/1/jobs/2/artifacts/500.html":
+			w.WriteHeader(http.StatusInternalServerError)
+		case "/projects/1/jobs/2/artifacts/404.html":
+			w.WriteHeader(http.StatusNotFound)
+		}
+		fmt.Fprint(w, content)
+	}))
+	defer testServer.Close()
+
+	cases := []struct {
+		Path         string
+		Status       int
+		Content      string
+		Length       string
+		CacheControl string
+		ContentType  string
+		Description  string
+	}{
+		{
+			"/200.html",
+			http.StatusOK,
+			content,
+			"90",
+			"max-age=3600",
+			"text/html; charset=utf-8",
+			"basic successful request",
+		},
+		{
+			"/max-caching.html",
+			http.StatusIMUsed,
+			content,
+			"90",
+			"max-age=3600",
+			"text/html; charset=utf-8",
+			"max caching request",
+		},
+		{
+			"/non-caching.html",
+			http.StatusTeapot,
+			content,
+			"90",
+			"",
+			"text/html; charset=utf-8",
+			"no caching request",
+		},
+	}
+
+	for _, c := range cases {
+		result := httptest.NewRecorder()
+		reqURL, err := url.Parse(c.Path)
+		assert.NoError(t, err)
+		r := &http.Request{URL: reqURL}
+		art := &Artifact{
+			server:  testServer.URL,
+			client:  &http.Client{Timeout: time.Second * time.Duration(1)},
+			pattern: regexp.MustCompile(fmt.Sprintf(hostPatternTemplate, "gitlab-example.io")),
+		}
+
+		assert.True(t, art.TryMakeRequest("artifact~1~2.gitlab-example.io", result, r))
+		assert.Equal(t, c.ContentType, result.Header().Get("Content-Type"))
+		assert.Equal(t, c.Length, result.Header().Get("Content-Length"))
+		assert.Equal(t, c.CacheControl, result.Header().Get("Cache-Control"))
+		assert.Equal(t, c.Content, string(result.Body.Bytes()))
+		assert.Equal(t, c.Status, result.Code)
+	}
+}
+
+func TestBuildURL(t *testing.T) {
+	cases := []struct {
+		RawServer   string
+		Host        string
+		Path        string
+		Expected    string
+		PagesDomain string
+		Ok          bool
+		Description string
+	}{
+		{
+			"https://gitlab.com/api/v4",
+			"artifact~1~2.gitlab.io",
+			"/path/to/file.txt",
+			"https://gitlab.com/api/v4/projects/1/jobs/2/artifacts/path/to/file.txt",
+			"gitlab.io",
+			true,
+			"basic case",
+		},
+		{
+			"https://gitlab.com/api/v4/",
+			"artifact~1~2.gitlab.io",
+			"/path/to/file.txt",
+			"https://gitlab.com/api/v4/projects/1/jobs/2/artifacts/path/to/file.txt",
+			"gitlab.io",
+			true,
+			"basic case 2",
+		},
+		{
+			"https://gitlab.com/api/v4",
+			"artifact~1~2.gitlab.io",
+			"path/to/file.txt",
+			"https://gitlab.com/api/v4/projects/1/jobs/2/artifacts/path/to/file.txt",
+			"gitlab.io",
+			true,
+			"basic case 3",
+		},
+		{
+			"https://gitlab.com/api/v4/",
+			"artifact~1~2.gitlab.io",
+			"path/to/file.txt",
+			"https://gitlab.com/api/v4/projects/1/jobs/2/artifacts/path/to/file.txt",
+			"gitlab.io",
+			true,
+			"basic case 4",
+		},
+		{
+			"https://gitlab.com/api/v4",
+			"artifact~1~2.gitlab.io",
+			"",
+			"https://gitlab.com/api/v4/projects/1/jobs/2/artifacts",
+			"gitlab.io",
+			true,
+			"basic case 5",
+		},
+		{
+			"https://gitlab.com/api/v4/",
+			"artifact~1~2.gitlab.io",
+			"",
+			"https://gitlab.com/api/v4/projects/1/jobs/2/artifacts",
+			"gitlab.io",
+			true,
+			"basic case 6",
+		},
+		{
+			"https://gitlab.com/api/v4",
+			"artifact~1~2.gitlab.io",
+			"/",
+			"https://gitlab.com/api/v4/projects/1/jobs/2/artifacts/",
+			"gitlab.io",
+			true,
+			"basic case 7",
+		},
+		{
+			"https://gitlab.com/api/v4/",
+			"artifact~1~2.gitlab.io",
+			"/",
+			"https://gitlab.com/api/v4/projects/1/jobs/2/artifacts/",
+			"gitlab.io",
+			true,
+			"basic case 8",
+		},
+		{
+			"https://gitlab.com/api/v4",
+			"artifact~100000~200000.gitlab.io",
+			"/file.txt",
+			"https://gitlab.com/api/v4/projects/100000/jobs/200000/artifacts/file.txt",
+			"gitlab.io",
+			true,
+			"expanded case",
+		},
+		{
+			"https://gitlab.com/api/v4/",
+			"artifact~1~2.gitlab.io",
+			"/file.txt",
+			"https://gitlab.com/api/v4/projects/1/jobs/2/artifacts/file.txt",
+			"gitlab.io",
+			true,
+			"server with tailing slash",
+		},
+		{
+			"https://gitlab.com/api/v4",
+			"artifact~A~B.gitlab.io",
+			"/index.html",
+			"",
+			"example.com",
+			false,
+			"non matching domain and request",
+		},
+		{
+			"",
+			"artifact~A~B.gitlab.io",
+			"",
+			"",
+			"",
+			false,
+			"un-parseable Host",
+		},
+	}
+
+	for _, c := range cases {
+		a := &Artifact{server: c.RawServer, pattern: regexp.MustCompile(fmt.Sprintf(hostPatternTemplate, c.PagesDomain))}
+		u, ok := a.buildURL(c.Host, c.Path)
+		assert.Equal(t, c.Ok, ok, c.Description)
+		if c.Ok {
+			assert.Equal(t, c.Expected, u.String(), c.Description)
+		}
+	}
+}
+
+func TestMatchHostGen(t *testing.T) {
+	cases := []struct {
+		URLHost     string
+		PagesDomain string
+		Expected    bool
+		Description string
+	}{
+		{
+			"artifact~1~2.gitlab.io",
+			"gitlab.io",
+			true,
+			"basic case",
+		},
+		{
+			"ARTIFACT~1~2.gitlab.io",
+			"gitlab.io",
+			true,
+			"capital letters case",
+		},
+		{
+			"ARTIFACT~11234~2908908.gitlab.io",
+			"gitlab.io",
+			true,
+			"additional capital letters case",
+		},
+		{
+			"artifact~10000~20000.gitlab.io",
+			"gitlab.io",
+			true,
+			"expanded case",
+		},
+		{
+			"artifact~86753095555~55550935768.gitlab.io",
+			"gitlab.io",
+			true,
+			"large number case",
+		},
+		{
+			"artifact~one~two.gitlab.io",
+			"gitlab.io",
+			false,
+			"letters rather than numbers",
+		},
+		{
+			"artifact~One111~tWo222.gitlab.io",
+			"gitlab.io",
+			false,
+			"Mixture of alphanumeric",
+		},
+		{
+			"artifact~!@#$%~%$#@!.gitlab.io",
+			"gitlab.io",
+			false,
+			"special characters",
+		},
+		{
+			"artifact~1.gitlab.io",
+			"gitlab.io",
+			false,
+			"not enough ids",
+		},
+		{
+			"artifact~1~2~34444~1~4.gitlab.io",
+			"gitlab.io",
+			false,
+			"too many ids",
+		},
+		{
+			"artifact~1~2.gitlab.io",
+			"otherhost.io",
+			false,
+			"different domain / suffix",
+		},
+	}
+
+	for _, c := range cases {
+		reg := hostPatternGen(c.PagesDomain)
+		assert.Equal(t, c.Expected, reg.MatchString(c.URLHost), c.Description)
+	}
+}
diff --git a/internal/httperrors/httperrors.go b/internal/httperrors/httperrors.go
new file mode 100644
index 00000000..82d43fc5
--- /dev/null
+++ b/internal/httperrors/httperrors.go
@@ -0,0 +1,162 @@
+package httperrors
+
+import (
+	"fmt"
+	"net/http"
+)
+
+type content struct {
+	status       int
+	title        string
+	statusString string
+	header       string
+	subHeader    string
+}
+
+var (
+	content404 = content{
+		http.StatusNotFound,
+		"The page you're looking for could not be found (404)",
+		"404",
+		"The page you're looking for could not be found.",
+		`<p>The resource that you are attempting to access does not exist or you don't have the necessary permissions to view it.</p>
+     <p>Make sure the address is correct and that the page hasn't moved.</p>
+     <p>Please contact your GitLab administrator if you think this is a mistake.</p>`,
+	}
+	content500 = content{
+		http.StatusInternalServerError,
+		"Something went wrong (500)",
+		"500",
+		"Whoops, something went wrong on our end.",
+		`<p>Try refreshing the page, or going back and attempting the action again.</p>
+     <p>Please contact your GitLab administrator if this problem persists.</p>`,
+	}
+
+	content502 = content{
+		http.StatusBadGateway,
+		"Something went wrong (502)",
+		"502",
+		"Whoops, something went wrong on our end.",
+		`<p>Try refreshing the page, or going back and attempting the action again.</p>
+     <p>Please contact your GitLab administrator if this problem persists.</p>`,
+	}
+)
+
+const predefinedErrorPage = `
+<!DOCTYPE html>
+<html>
+<head>
+  <meta content="width=device-width, initial-scale=1, maximum-scale=1" name="viewport">
+  <title>%v</title>
+  <style>
+    body {
+      color: #666;
+      text-align: center;
+      font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
+      margin: auto;
+      font-size: 14px;
+    }
+
+    h1 {
+      font-size: 56px;
+      line-height: 100px;
+      font-weight: 400;
+      color: #456;
+    }
+
+    h2 {
+      font-size: 24px;
+      color: #666;
+      line-height: 1.5em;
+    }
+
+    h3 {
+      color: #456;
+      font-size: 20px;
+      font-weight: 400;
+      line-height: 28px;
+    }
+
+    hr {
+      max-width: 800px;
+      margin: 18px auto;
+      border: 0;
+      border-top: 1px solid #EEE;
+      border-bottom: 1px solid white;
+    }
+
+    img {
+      max-width: 40vw;
+      display: block;
+      margin: 40px auto;
+    }
+
+    a {
+      line-height: 100px;
+      font-weight: 400;
+      color: #4A8BEE;
+      font-size: 18px;
+      text-decoration: none;
+    }
+
+    .container {
+      margin: auto 20px;
+    }
+
+    .go-back {
+      display: none;
+    }
+
+  </style>
+</head>
+
+<body>
+  <img src="data:image/svg+xml;base64,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"
+       alt="GitLab Logo" />
+  <h1>
+    %v
+  </h1>
+  <div class="container">
+    <h3>%v</h3>
+    <hr />
+    %v
+    <a href="javascript:history.back()" class="js-go-back go-back">Go back</a>
+  </div>
+  <script>
+    (function () {
+      var goBack = document.querySelector('.js-go-back');
+
+      if (history.length > 1) {
+        goBack.style.display = 'inline';
+      }
+    })();
+  </script>
+</body>
+</html>
+`
+
+func generateErrorHTML(c content) string {
+	return fmt.Sprintf(predefinedErrorPage, c.title, c.statusString, c.header, c.subHeader)
+}
+
+func serveErrorPage(w http.ResponseWriter, c content) {
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	w.Header().Set("X-Content-Type-Options", "nosniff")
+	w.WriteHeader(c.status)
+	fmt.Fprintln(w, generateErrorHTML(c))
+}
+
+// Serve404 returns a 404 error response / HTML page to the http.ResponseWriter
+func Serve404(w http.ResponseWriter) {
+	serveErrorPage(w, content404)
+}
+
+// Serve500 returns a 500 error response / HTML page to the http.ResponseWriter
+func Serve500(w http.ResponseWriter) {
+	serveErrorPage(w, content500)
+}
+
+// Serve502 returns a 502 error response / HTML page to the http.ResponseWriter
+func Serve502(w http.ResponseWriter) {
+	serveErrorPage(w, content502)
+}
diff --git a/internal/httperrors/httperrors_test.go b/internal/httperrors/httperrors_test.go
new file mode 100644
index 00000000..1a79d850
--- /dev/null
+++ b/internal/httperrors/httperrors_test.go
@@ -0,0 +1,105 @@
+package httperrors
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// creates a new implementation of http.ResponseWriter that allows the
+// casting of values in order to aid testing efforts.
+type testResponseWriter struct {
+	status  int
+	content string
+	http.ResponseWriter
+}
+
+func newTestResponseWriter(w http.ResponseWriter) *testResponseWriter {
+	return &testResponseWriter{0, "", w}
+}
+
+func (w *testResponseWriter) Status() int {
+	return w.status
+}
+
+func (w *testResponseWriter) Content() string {
+	return w.content
+}
+
+func (w *testResponseWriter) Header() http.Header {
+	return w.ResponseWriter.Header()
+}
+
+func (w *testResponseWriter) Write(data []byte) (int, error) {
+	w.content = string(data)
+	return w.ResponseWriter.Write(data)
+}
+
+func (w *testResponseWriter) WriteHeader(statusCode int) {
+	w.status = statusCode
+	w.ResponseWriter.WriteHeader(statusCode)
+}
+
+var (
+	testingContent = content{
+		http.StatusNotFound,
+		"Title",
+		"533",
+		"Header test",
+		"subheader text",
+	}
+)
+
+func TestGenerateemailHTML(t *testing.T) {
+	actual := generateErrorHTML(testingContent)
+	assert.Contains(t, actual, testingContent.title)
+	assert.Contains(t, actual, testingContent.statusString)
+	assert.Contains(t, actual, testingContent.header)
+	assert.Contains(t, actual, testingContent.subHeader)
+}
+
+func TestServeErrorPage(t *testing.T) {
+	w := newTestResponseWriter(httptest.NewRecorder())
+	serveErrorPage(w, testingContent)
+	assert.Equal(t, w.Header().Get("Content-Type"), "text/html; charset=utf-8")
+	assert.Equal(t, w.Header().Get("X-Content-Type-Options"), "nosniff")
+	assert.Equal(t, w.Status(), testingContent.status)
+}
+
+func TestServe404(t *testing.T) {
+	w := newTestResponseWriter(httptest.NewRecorder())
+	Serve404(w)
+	assert.Equal(t, w.Header().Get("Content-Type"), "text/html; charset=utf-8")
+	assert.Equal(t, w.Header().Get("X-Content-Type-Options"), "nosniff")
+	assert.Equal(t, w.Status(), content404.status)
+	assert.Contains(t, w.Content(), content404.title)
+	assert.Contains(t, w.Content(), content404.statusString)
+	assert.Contains(t, w.Content(), content404.header)
+	assert.Contains(t, w.Content(), content404.subHeader)
+}
+
+func TestServe500(t *testing.T) {
+	w := newTestResponseWriter(httptest.NewRecorder())
+	Serve500(w)
+	assert.Equal(t, w.Header().Get("Content-Type"), "text/html; charset=utf-8")
+	assert.Equal(t, w.Header().Get("X-Content-Type-Options"), "nosniff")
+	assert.Equal(t, w.Status(), content500.status)
+	assert.Contains(t, w.Content(), content500.title)
+	assert.Contains(t, w.Content(), content500.statusString)
+	assert.Contains(t, w.Content(), content500.header)
+	assert.Contains(t, w.Content(), content500.subHeader)
+}
+
+func TestServe502(t *testing.T) {
+	w := newTestResponseWriter(httptest.NewRecorder())
+	Serve502(w)
+	assert.Equal(t, w.Header().Get("Content-Type"), "text/html; charset=utf-8")
+	assert.Equal(t, w.Header().Get("X-Content-Type-Options"), "nosniff")
+	assert.Equal(t, w.Status(), content502.status)
+	assert.Contains(t, w.Content(), content502.title)
+	assert.Contains(t, w.Content(), content502.statusString)
+	assert.Contains(t, w.Content(), content502.header)
+	assert.Contains(t, w.Content(), content502.subHeader)
+}
diff --git a/main.go b/main.go
index cacddb4f..1cfac409 100644
--- a/main.go
+++ b/main.go
@@ -1,8 +1,10 @@
 package main
 
 import (
+	"errors"
 	"flag"
 	"log"
+	"net/url"
 	"os"
 	"strings"
 )
@@ -14,18 +16,22 @@ var VERSION = "dev"
 var REVISION = "HEAD"
 
 var (
-	pagesRootCert  = flag.String("root-cert", "", "The default path to file certificate to serve static pages")
-	pagesRootKey   = flag.String("root-key", "", "The default path to file certificate to serve static pages")
-	redirectHTTP   = flag.Bool("redirect-http", false, "Redirect pages from HTTP to HTTPS")
-	useHTTP2       = flag.Bool("use-http2", true, "Enable HTTP2 support")
-	pagesRoot      = flag.String("pages-root", "shared/pages", "The directory where pages are stored")
-	pagesDomain    = flag.String("pages-domain", "gitlab-example.com", "The domain to serve static pages")
-	pagesStatus    = flag.String("pages-status", "", "The url path for a status page, e.g., /@status")
-	metricsAddress = flag.String("metrics-address", "", "The address to listen on for metrics requests")
-	daemonUID      = flag.Uint("daemon-uid", 0, "Drop privileges to this user")
-	daemonGID      = flag.Uint("daemon-gid", 0, "Drop privileges to this group")
-
-	disableCrossOriginRequests = flag.Bool("disable-cross-origin-requests", false, "Disable cross-origin requests")
+	pagesRootCert          = flag.String("root-cert", "", "The default path to file certificate to serve static pages")
+	pagesRootKey           = flag.String("root-key", "", "The default path to file certificate to serve static pages")
+	redirectHTTP           = flag.Bool("redirect-http", false, "Redirect pages from HTTP to HTTPS")
+	useHTTP2               = flag.Bool("use-http2", true, "Enable HTTP2 support")
+	pagesRoot              = flag.String("pages-root", "shared/pages", "The directory where pages are stored")
+	pagesDomain            = flag.String("pages-domain", "gitlab-example.com", "The domain to serve static pages")
+	artifactsServer        = flag.String("artifacts-server", "", "API URL to proxy artifact requests to, e.g.: 'https://gitlab.com/api/v4'")
+	artifactsServerTimeout = flag.Int("artifacts-server-timeout", 10, "Timeout (in seconds) for a proxied request to the artifacts server")
+	pagesStatus            = flag.String("pages-status", "", "The url path for a status page, e.g., /@status")
+	metricsAddress         = flag.String("metrics-address", "", "The address to listen on for metrics requests")
+	daemonUID              = flag.Uint("daemon-uid", 0, "Drop privileges to this user")
+	daemonGID              = flag.Uint("daemon-gid", 0, "Drop privileges to this group")
+
+	disableCrossOriginRequests     = flag.Bool("disable-cross-origin-requests", false, "Disable cross-origin requests")
+	errArtifactSchemaUnsupported   = errors.New("artifacts-server scheme must be either http:// or https://")
+	errArtifactsServerTimeoutValue = errors.New("artifacts-server-timeout must be greater than or equal to 1")
 )
 
 func configFromFlags() appConfig {
@@ -45,6 +51,27 @@ func configFromFlags() appConfig {
 		config.RootKey = readFile(*pagesRootKey)
 	}
 
+	if *artifactsServerTimeout < 1 {
+		log.Fatal(errArtifactsServerTimeoutValue)
+	}
+
+	if *artifactsServer != "" {
+		u, err := url.Parse(*artifactsServer)
+		if err != nil {
+			log.Fatal(err)
+		}
+		// url.Parse ensures that the Scheme arttribute is always lower case.
+		if u.Scheme != "http" && u.Scheme != "https" {
+			log.Fatal(errArtifactSchemaUnsupported)
+		}
+
+		if *artifactsServerTimeout < 1 {
+			log.Fatal(errArtifactsServerTimeoutValue)
+		}
+
+		config.ArtifactsServerTimeout = *artifactsServerTimeout
+		config.ArtifactsServer = *artifactsServer
+	}
 	return config
 }
author	J. Shuster <joshuagregoryshuster@gmail.com>	2017-09-08 11:58:42 +0300
committer	Nick Thomas <nick@gitlab.com>	2017-09-08 11:58:42 +0300
commit	0a144bc6055b41fac726fdc6eeaa7150f622bd20 (patch)
tree	9ed2a4dbecbd8146245ae8fa609cd9f54d038bf6
parent	0173d4e6b6b17443155d121a9098d0e742b9c4e3 (diff)