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Merged
merged 2 commits into from
Feb 29, 2024
Merged

chore: consolidate various randomPort() implementations #12362

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776f130
chore: DRY up various randomPort() implementations
johnstcn Feb 29, 2024
257c8d1
fixup! chore: DRY up various randomPort() implementations
johnstcn Feb 29, 2024
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17 changes: 1 addition & 16 deletions agent/agent_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,6 @@ import (
"errors"
"fmt"
"io"
"math/rand"
"net"
"net/http"
"net/http/httptest"
Expand Down Expand Up @@ -838,7 +837,7 @@ func TestAgent_TCPRemoteForwarding(t *testing.T) {
var ll net.Listener
var err error
for {
randomPort = pickRandomPort()
randomPort = testutil.RandomPortNoListen(t)
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nit: testutil.FreePort?

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This one isn't guaranteed to be free and relies on pure randommess.
Regarding the other implementation, I just picked the existing name.
We can rename later if need be. 👍

addr := net.TCPAddrFromAddrPort(netip.AddrPortFrom(localhost, randomPort))
ll, err = sshClient.ListenTCP(addr)
if err != nil {
Expand Down Expand Up @@ -2666,20 +2665,6 @@ func (s *syncWriter) Write(p []byte) (int, error) {
return s.w.Write(p)
}

// pickRandomPort picks a random port number for the ephemeral range. We do this entirely randomly
// instead of opening a listener and closing it to find a port that is likely to be free, since
// sometimes the OS reallocates the port very quickly.
func pickRandomPort() uint16 {
const (
// Overlap of windows, linux in https://en.wikipedia.org/wiki/Ephemeral_port
min = 49152
max = 60999
)
n := max - min
x := rand.Intn(n) //nolint: gosec
return uint16(min + x)
}

// echoOnce accepts a single connection, reads 4 bytes and echos them back
func echoOnce(t *testing.T, ll net.Listener) {
t.Helper()
Expand Down
13 changes: 2 additions & 11 deletions cli/server_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -937,22 +937,13 @@ func TestServer(t *testing.T) {
t.Run("Prometheus", func(t *testing.T) {
t.Parallel()

randomPort := func(t *testing.T) int {
random, err := net.Listen("tcp", "127.0.0.1:0")
require.NoError(t, err)
_ = random.Close()
tcpAddr, valid := random.Addr().(*net.TCPAddr)
require.True(t, valid)
return tcpAddr.Port
}

t.Run("DBMetricsDisabled", func(t *testing.T) {
t.Parallel()

ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitShort)
defer cancel()

randPort := randomPort(t)
randPort := testutil.RandomPort(t)
inv, cfg := clitest.New(t,
"server",
"--in-memory",
Expand Down Expand Up @@ -1008,7 +999,7 @@ func TestServer(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitShort)
defer cancel()

randPort := randomPort(t)
randPort := testutil.RandomPort(t)
inv, cfg := clitest.New(t,
"server",
"--in-memory",
Expand Down
13 changes: 1 addition & 12 deletions enterprise/cli/provisionerdaemons_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,6 @@ import (
"bufio"
"context"
"fmt"
"net"
"net/http"
"strings"
"testing"
Expand Down Expand Up @@ -170,7 +169,7 @@ func TestProvisionerDaemon_SessionToken(t *testing.T) {
t.Run("PrometheusEnabled", func(t *testing.T) {
t.Parallel()

prometheusPort := randomPort(t)
prometheusPort := testutil.RandomPort(t)

// Configure CLI client
client, admin := coderdenttest.New(t, &coderdenttest.Options{
Expand Down Expand Up @@ -242,13 +241,3 @@ func TestProvisionerDaemon_SessionToken(t *testing.T) {
require.True(t, hasPromHTTP, "Prometheus HTTP metrics are missing")
})
}

// randomPort is a helper function to find a free random port, for instance to spawn Prometheus endpoint.
func randomPort(t *testing.T) int {
random, err := net.Listen("tcp", "127.0.0.1:0")
require.NoError(t, err)
_ = random.Close()
tcpAddr, valid := random.Addr().(*net.TCPAddr)
require.True(t, valid)
return tcpAddr.Port
}
4 changes: 2 additions & 2 deletions enterprise/cli/proxyserver_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -63,7 +63,7 @@ func Test_Headers(t *testing.T) {
func TestWorkspaceProxy_Server_PrometheusEnabled(t *testing.T) {
t.Parallel()

prometheusPort := randomPort(t)
prometheusPort := testutil.RandomPort(t)

var wg sync.WaitGroup
wg.Add(1)
Expand Down Expand Up @@ -96,7 +96,7 @@ func TestWorkspaceProxy_Server_PrometheusEnabled(t *testing.T) {
"--primary-access-url", srv.URL,
"--proxy-session-token", "test-token",
"--access-url", "http://foobar:3001",
"--http-address", fmt.Sprintf("127.0.0.1:%d", randomPort(t)),
"--http-address", fmt.Sprintf("127.0.0.1:%d", testutil.RandomPort(t)),
"--prometheus-enable",
"--prometheus-address", fmt.Sprintf("127.0.0.1:%d", prometheusPort),
)
Expand Down
2 changes: 1 addition & 1 deletion enterprise/cli/server_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -22,7 +22,7 @@ func TestServer(t *testing.T) {
var root cli.RootCmd
cmd, err := root.Command(root.EnterpriseSubcommands())
require.NoError(t, err)
port := randomPort(t)
port := testutil.RandomPort(t)
inv, _ := clitest.NewWithCommand(t, cmd,
"server",
"--in-memory",
Expand Down
45 changes: 45 additions & 0 deletions testutil/port.go
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Original file line number Diff line number Diff line change
@@ -0,0 +1,45 @@
package testutil

import (
"math/rand"
"net"
"sync"
"testing"
"time"

"github.com/stretchr/testify/require"
)

var (
// nolint:gosec // not used for cryptography
rnd = rand.New(rand.NewSource(time.Now().Unix()))
rndMu sync.Mutex
)

// RandomPort is a helper function to find a free random port.
// Note that the OS may reallocate the port very quickly, so
// this is not _guaranteed_.
func RandomPort(t *testing.T) int {
random, err := net.Listen("tcp", "127.0.0.1:0")
require.NoError(t, err, "failed to listen on localhost")
_ = random.Close()
tcpAddr, valid := random.Addr().(*net.TCPAddr)
require.True(t, valid, "random port address is not a *net.TCPAddr?!")
return tcpAddr.Port
}

// RandomPortNoListen returns a random port in the ephemeral port range.
// Does not attempt to listen and close to find a port as the OS may
// reallocate the port very quickly.
func RandomPortNoListen(*testing.T) uint16 {
const (
// Overlap of windows, linux in https://en.wikipedia.org/wiki/Ephemeral_port
min = 49152
max = 60999
)
n := max - min
rndMu.Lock()
x := rnd.Intn(n)
rndMu.Unlock()
return uint16(min + x)
}