Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Adding web.external-url and web.route-prefix flags #515

Merged
merged 6 commits into from Sep 11, 2019
Merged

Adding web.external-url and web.route-prefix flags #515

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
67a8809
Add web.external-url and web.route-prefix flags
snebel29 Sep 4, 2019
d268388
Match logic and signature for computeExternalURL
snebel29 Sep 8, 2019
3d02120
Redirect over routePrefix on non-matching path
snebel29 Sep 8, 2019
37c5abb
On root path redirect over externalURL instead of routePrefix
snebel29 Sep 9, 2019
fc05ba3
Fix registering / twice
snebel29 Sep 9, 2019
8712d11
Use path-relative paths in html
snebel29 Sep 10, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
3 changes: 2 additions & 1 deletion go.mod
View file
Open in desktop
Expand Up @@ -6,10 +6,11 @@ require (
github.com/go-kit/kit v0.8.0
github.com/kr/pretty v0.1.0 // indirect
github.com/miekg/dns v1.1.14
github.com/pkg/errors v0.8.1 // indirect
github.com/pkg/errors v0.8.1
github.com/prometheus/client_golang v1.0.0
github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90
github.com/prometheus/common v0.6.0
github.com/stretchr/testify v1.3.0
golang.org/x/crypto v0.0.0-20190617133340-57b3e21c3d56 // indirect
golang.org/x/net v0.0.0-20190613194153-d28f0bde5980
golang.org/x/sync v0.0.0-20190423024810-112230192c58 // indirect
Expand Down
93 changes: 77 additions & 16 deletions main.go
View file
Open in desktop
Expand Up @@ -18,16 +18,20 @@ import (
"context"
"fmt"
"html"
"net"
"net/http"
_ "net/http/pprof"
"net/url"
"os"
"os/signal"
"strconv"
"strings"
"syscall"
"time"

"github.com/go-kit/kit/log"
"github.com/go-kit/kit/log/level"
"github.com/pkg/errors"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"github.com/prometheus/common/expfmt"
Expand All @@ -51,6 +55,8 @@ var (
timeoutOffset = kingpin.Flag("timeout-offset", "Offset to subtract from timeout in seconds.").Default("0.5").Float64()
configCheck = kingpin.Flag("config.check", "If true validate the config file and then exit.").Default().Bool()
historyLimit = kingpin.Flag("history.limit", "The maximum amount of items to keep in the history.").Default("100").Uint()
externalURL = kingpin.Flag("web.external-url", "The URL under which Blackbox exporter is externally reachable (for example, if Blackbox exporter is served via a reverse proxy). Used for generating relative and absolute links back to Blackbox exporter itself. If the URL has a path portion, it will be used to prefix all HTTP endpoints served by Blackbox exporter. If omitted, relevant URL components will be derived automatically.").PlaceHolder("<url>").String()
routePrefix = kingpin.Flag("web.route-prefix", "Prefix for the internal routes of web endpoints. Defaults to path of --web.external-url.").PlaceHolder("<path>").String()

Probers = map[string]prober.ProbeFn{
"http": prober.ProbeHTTP,
Expand Down Expand Up @@ -217,6 +223,25 @@ func run() int {

level.Info(logger).Log("msg", "Loaded config file")

// Infer or set Blackbox exporter externalURL
beURL, err := extURL(logger, os.Hostname, *listenAddress, *externalURL)
if err != nil {
level.Error(logger).Log("msg", "failed to determine external URL", "err", err)
return 1
}
level.Debug(logger).Log("externalURL", beURL.String())

// Make routePrefix default to externalURL path if empty string.
if *routePrefix == "" {
*routePrefix = beURL.Path
}
*routePrefix = "/" + strings.Trim(*routePrefix, "/")
level.Debug(logger).Log("routePrefix", *routePrefix)

if *routePrefix == "/" {
*routePrefix = ""
}

hup := make(chan os.Signal, 1)
reloadCh := make(chan chan error)
signal.Notify(hup, syscall.SIGHUP)
Expand All @@ -241,7 +266,7 @@ func run() int {
}
}()

http.HandleFunc("/-/reload",
http.HandleFunc(fmt.Sprintf("%s/-/reload", *routePrefix),
func(w http.ResponseWriter, r *http.Request) {
if r.Method != "POST" {
w.WriteHeader(http.StatusMethodNotAllowed)
Expand All @@ -255,25 +280,27 @@ func run() int {
http.Error(w, fmt.Sprintf("failed to reload config: %s", err), http.StatusInternalServerError)
}
})
http.Handle("/metrics", promhttp.Handler())
http.HandleFunc("/probe", func(w http.ResponseWriter, r *http.Request) {
http.Handle(fmt.Sprintf("%s/metrics", *routePrefix), promhttp.Handler())
http.HandleFunc(fmt.Sprintf("%s/probe", *routePrefix), func(w http.ResponseWriter, r *http.Request) {
sc.Lock()
conf := sc.C
sc.Unlock()
probeHandler(w, r, conf, logger, rh)
})
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
http.HandleFunc(fmt.Sprintf("%s/", *routePrefix), func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/html")
w.Write([]byte(`<html>
<head><title>Blackbox Exporter</title></head>
<body>
<h1>Blackbox Exporter</h1>
<p><a href="/probe?target=prometheus.io&module=http_2xx">Probe prometheus.io for http_2xx</a></p>
<p><a href="/probe?target=prometheus.io&module=http_2xx&debug=true">Debug probe prometheus.io for http_2xx</a></p>
<p><a href="/metrics">Metrics</a></p>
<p><a href="/config">Configuration</a></p>
<h2>Recent Probes</h2>
<table border='1'><tr><th>Module</th><th>Target</th><th>Result</th><th>Debug</th>`))
w.Write([]byte("<html>\n"))
w.Write([]byte(" <head><title>Blackbox Exporter</title></head>\n"))
w.Write([]byte(" <body>\n"))
w.Write([]byte(" <h1>Blackbox Exporter</h1>\n"))

w.Write([]byte(fmt.Sprintf(" <p><a href=\"%s/probe?target=prometheus.io&module=http_2xx\">Probe prometheus.io for http_2xx</a></p>\n", *routePrefix)))
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

We could use relative paths here, the blackbox exporter doesn't do anything fancy.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Great, since they are already relative urls I'll keep the code in this area the same then

w.Write([]byte(fmt.Sprintf(" <p><a href=\"%s/probe?target=prometheus.io&module=http_2xx&debug=true\">Debug probe prometheus.io for http_2xx</a></p>\n", *routePrefix)))
w.Write([]byte(fmt.Sprintf(" <p><a href=\"%s/metrics\">Metrics</a></p>\n", *routePrefix)))
w.Write([]byte(fmt.Sprintf(" <p><a href=\"%s/config\">Configuration</a></p>\n", *routePrefix)))

w.Write([]byte(" <h2>Recent Probes</h2>\n"))
w.Write([]byte(" <table border='1'><tr><th>Module</th><th>Target</th><th>Result</th><th>Debug</th>\n"))

results := rh.List()

Expand All @@ -291,7 +318,7 @@ func run() int {
</html>`))
})

http.HandleFunc("/logs", func(w http.ResponseWriter, r *http.Request) {
http.HandleFunc(fmt.Sprintf("%s/logs", *routePrefix), func(w http.ResponseWriter, r *http.Request) {
id, err := strconv.ParseInt(r.URL.Query().Get("id"), 10, 64)
if err != nil {
http.Error(w, "Invalid probe id", 500)
Expand All @@ -306,7 +333,7 @@ func run() int {
w.Write([]byte(result.debugOutput))
})

http.HandleFunc("/config", func(w http.ResponseWriter, r *http.Request) {
http.HandleFunc(fmt.Sprintf("%s/config", *routePrefix), func(w http.ResponseWriter, r *http.Request) {
sc.RLock()
c, err := yaml.Marshal(sc.C)
sc.RUnlock()
Expand Down Expand Up @@ -366,3 +393,37 @@ func getTimeout(r *http.Request, module config.Module, offset float64) (timeoutS

return timeoutSeconds, nil
}

func extURL(logger log.Logger, hostnamef func() (string, error), listen, external string) (*url.URL, error) {
if external == "" {
hostname, err := hostnamef()
if err != nil {
return nil, err
}
_, port, err := net.SplitHostPort(listen)
if err != nil {
return nil, err
}
if port == "" {
level.Warn(logger).Log("msg", "no port found for listen address", "address", listen)
}

external = fmt.Sprintf("http://%s:%s/", hostname, port)
}

u, err := url.Parse(external)
if err != nil {
return nil, err
}
if u.Scheme != "http" && u.Scheme != "https" {
return nil, errors.Errorf("%q: invalid %q scheme, only 'http' and 'https' are supported", u.String(), u.Scheme)
}

ppref := strings.TrimRight(u.Path, "/")
if ppref != "" && !strings.HasPrefix(ppref, "/") {
ppref = "/" + ppref
}
u.Path = ppref

return u, nil
}
79 changes: 79 additions & 0 deletions main_test.go
View file
Open in desktop
Expand Up @@ -15,12 +15,15 @@ package main

import (
"bytes"
"fmt"
"net/http"
"net/http/httptest"
"strings"
"testing"
"time"

"github.com/stretchr/testify/require"

"github.com/go-kit/kit/log"
"github.com/prometheus/client_golang/prometheus"
pconfig "github.com/prometheus/common/config"
Expand Down Expand Up @@ -137,3 +140,79 @@ func TestTimeoutIsSetCorrectly(t *testing.T) {
}
}
}

func TestExternalURL(t *testing.T) {
hostname := "foo"
for _, tc := range []struct {
hostnameResolver func() (string, error)
external string
listen string

expURL string
err bool
}{
{
listen: ":9093",
expURL: "http://" + hostname + ":9093",
},
{
listen: "localhost:9093",
expURL: "http://" + hostname + ":9093",
},
{
listen: "localhost:",
expURL: "http://" + hostname + ":",
},
{
external: "https://host.example.com",
expURL: "https://host.example.com",
},
{
external: "https://host.example.com/",
expURL: "https://host.example.com",
},
{
external: "http://host.example.com/alertmanager",
expURL: "http://host.example.com/alertmanager",
},
{
external: "http://host.example.com/alertmanager/",
expURL: "http://host.example.com/alertmanager",
},
{
external: "http://host.example.com/////alertmanager//",
expURL: "http://host.example.com/////alertmanager",
},
{
err: true,
},
{
hostnameResolver: func() (string, error) { return "", fmt.Errorf("some error") },
err: true,
},
{
external: "://broken url string",
err: true,
},
{
external: "host.example.com:8080",
err: true,
},
} {
tc := tc
if tc.hostnameResolver == nil {
tc.hostnameResolver = func() (string, error) {
return hostname, nil
}
}
t.Run(fmt.Sprintf("external=%q,listen=%q", tc.external, tc.listen), func(t *testing.T) {
u, err := extURL(log.NewNopLogger(), tc.hostnameResolver, tc.listen, tc.external)
if tc.err {
require.Error(t, err)
return
}
require.NoError(t, err)
require.Equal(t, tc.expURL, u.String())
})
}
}
15 changes: 15 additions & 0 deletions vendor/github.com/davecgh/go-spew/LICENSE
View file
Open in desktop

Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.