Build modified streamline images

The official image from streamline does not currently work for the arm64
platform. As a temporary measure, the source code and docker build scripts
have been lifted from the official images and are used to build locally.

Some additional modifications are made to reduce overall image size, these
are documented in docker/README.md

docker/streamline-src/vendor/symfony/var-dumper/Server/Connection.php

@@ -0,0 +1,97 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\VarDumper\Server;
+
+use Symfony\Component\VarDumper\Cloner\Data;
+use Symfony\Component\VarDumper\Dumper\ContextProvider\ContextProviderInterface;
+
+/**
+ * Forwards serialized Data clones to a server.
+ *
+ * @author Maxime Steinhausser <maxime.steinhausser@gmail.com>
+ */
+class Connection
+{
+    private string $host;
+    private array $contextProviders;
+
+    /**
+     * @var resource|null
+     */
+    private $socket;
+
+    /**
+     * @param string                     $host             The server host
+     * @param ContextProviderInterface[] $contextProviders Context providers indexed by context name
+     */
+    public function __construct(string $host, array $contextProviders = [])
+    {
+        if (!str_contains($host, '://')) {
+            $host = 'tcp://'.$host;
+        }
+
+        $this->host = $host;
+        $this->contextProviders = $contextProviders;
+    }
+
+    public function getContextProviders(): array
+    {
+        return $this->contextProviders;
+    }
+
+    public function write(Data $data): bool
+    {
+        $socketIsFresh = !$this->socket;
+        if (!$this->socket = $this->socket ?: $this->createSocket()) {
+            return false;
+        }
+
+        $context = ['timestamp' => microtime(true)];
+        foreach ($this->contextProviders as $name => $provider) {
+            $context[$name] = $provider->getContext();
+        }
+        $context = array_filter($context);
+        $encodedPayload = base64_encode(serialize([$data, $context]))."\n";
+
+        set_error_handler(static fn () => null);
+        try {
+            if (-1 !== stream_socket_sendto($this->socket, $encodedPayload)) {
+                return true;
+            }
+            if (!$socketIsFresh) {
+                stream_socket_shutdown($this->socket, \STREAM_SHUT_RDWR);
+                fclose($this->socket);
+                $this->socket = $this->createSocket();
+            }
+            if (-1 !== stream_socket_sendto($this->socket, $encodedPayload)) {
+                return true;
+            }
+        } finally {
+            restore_error_handler();
+        }
+
+        return false;
+    }
+
+    /**
+     * @return resource|null
+     */
+    private function createSocket()
+    {
+        set_error_handler(static fn () => null);
+        try {
+            return stream_socket_client($this->host, $errno, $errstr, 3) ?: null;
+        } finally {
+            restore_error_handler();
+        }
+    }
+}

docker/streamline-src/vendor/symfony/var-dumper/Server/DumpServer.php

@@ -0,0 +1,109 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\VarDumper\Server;
+
+use Psr\Log\LoggerInterface;
+use Symfony\Component\VarDumper\Cloner\Data;
+use Symfony\Component\VarDumper\Cloner\Stub;
+
+/**
+ * A server collecting Data clones sent by a ServerDumper.
+ *
+ * @author Maxime Steinhausser <maxime.steinhausser@gmail.com>
+ *
+ * @final
+ */
+class DumpServer
+{
+    private string $host;
+    private ?LoggerInterface $logger;
+
+    /**
+     * @var resource|null
+     */
+    private $socket;
+
+    public function __construct(string $host, ?LoggerInterface $logger = null)
+    {
+        if (!str_contains($host, '://')) {
+            $host = 'tcp://'.$host;
+        }
+
+        $this->host = $host;
+        $this->logger = $logger;
+    }
+
+    public function start(): void
+    {
+        if (!$this->socket = stream_socket_server($this->host, $errno, $errstr)) {
+            throw new \RuntimeException(sprintf('Server start failed on "%s": ', $this->host).$errstr.' '.$errno);
+        }
+    }
+
+    public function listen(callable $callback): void
+    {
+        if (null === $this->socket) {
+            $this->start();
+        }
+
+        foreach ($this->getMessages() as $clientId => $message) {
+            $this->logger?->info('Received a payload from client {clientId}', ['clientId' => $clientId]);
+
+            $payload = @unserialize(base64_decode($message), ['allowed_classes' => [Data::class, Stub::class]]);
+
+            // Impossible to decode the message, give up.
+            if (false === $payload) {
+                $this->logger?->warning('Unable to decode a message from {clientId} client.', ['clientId' => $clientId]);
+
+                continue;
+            }
+
+            if (!\is_array($payload) || \count($payload) < 2 || !$payload[0] instanceof Data || !\is_array($payload[1])) {
+                $this->logger?->warning('Invalid payload from {clientId} client. Expected an array of two elements (Data $data, array $context)', ['clientId' => $clientId]);
+
+                continue;
+            }
+
+            [$data, $context] = $payload;
+
+            $callback($data, $context, $clientId);
+        }
+    }
+
+    public function getHost(): string
+    {
+        return $this->host;
+    }
+
+    private function getMessages(): iterable
+    {
+        $sockets = [(int) $this->socket => $this->socket];
+        $write = [];
+
+        while (true) {
+            $read = $sockets;
+            stream_select($read, $write, $write, null);
+
+            foreach ($read as $stream) {
+                if ($this->socket === $stream) {
+                    $stream = stream_socket_accept($this->socket);
+                    $sockets[(int) $stream] = $stream;
+                } elseif (feof($stream)) {
+                    unset($sockets[(int) $stream]);
+                    fclose($stream);
+                } else {
+                    yield (int) $stream => fgets($stream);
+                }
+            }
+        }
+    }
+}