Show the progress of parallel builds live

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Changed
+
+* The parallel builds show their progress live: one line per service in a terminal, every line prefixed by its service anywhere else.
+
 ## 0.10.0 - 2026-10-06
 
 ### Added

doc/tasks.md

@@ -58,8 +58,10 @@ castor docker:build app                 # a single service
 castor docker:build --profiles builder  # restrict to a profile
 ```
 
-`--parallel` builds each service on its own, all of them in parallel, and
-prints the log of each one once it is done. Built together, services sharing a
+`--parallel` builds each service on its own, all of them in parallel. A
+terminal shows one line per service with the step it is at, and the full log of
+the builds that failed once they are all done; anywhere else, a CI log or a
+pipe, every line streams as it comes, prefixed by its service. Built together, services sharing a
 stage — an application and its builder sharing `php-base` — race their build
 caches, and BuildKit randomly rebuilds the steps of all but one of them
 ([moby/buildkit#6418](https://github.com/moby/buildkit/issues/6418)). Turn it on

src/Build/BoardBuildReporter.php

@@ -0,0 +1,152 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Castor\Docker\Build;
+
+use Symfony\Component\Console\Formatter\OutputFormatter;
+use Symfony\Component\Console\Helper\Helper;
+use Symfony\Component\Console\Output\ConsoleSectionOutput;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Terminal;
+
+/**
+ * One line per service, redrawn in place with the step it is at, the way
+ * BuildKit shows a single build in a terminal. The log of a failed build is
+ * printed in full once they are all done.
+ */
+final class BoardBuildReporter implements BuildReporter
+{
+    private const SPINNER = ['⠋', '⠙', '⠹', '⠸', '⠼', '⠴', '⠦', '⠧', '⠇', '⠏'];
+    private const REFRESH = 0.05;
+    private const SPIN = 0.08;
+
+    /** @var array<string, array{start: float, end: ?float, successful: ?bool, steps: array<int, string>, active: array<int, true>, log: list<string>}> */
+    private array $builds = [];
+    private int $width;
+    private float $renderedAt = 0;
+
+    /**
+     * @param non-empty-list<string> $services
+     */
+    public function __construct(
+        private readonly ConsoleSectionOutput $section,
+        private readonly OutputInterface $output,
+        array $services,
+        private readonly ?int $terminalWidth = null,
+    ) {
+        $this->width = max(array_map(strlen(...), $services));
+        $now = microtime(true);
+
+        foreach ($services as $service) {
+            $this->builds[$service] = ['start' => $now, 'end' => null, 'successful' => null, 'steps' => [], 'active' => [], 'log' => []];
+        }
+    }
+
+    public function line(string $service, string $line): void
+    {
+        $build = &$this->builds[$service];
+        $build['log'][] = $line;
+
+        // "#5 [app 2/8] RUN ..." names step 5, then "#5 0.42 <output>" and
+        // "#5 DONE 1.2s" follow it.
+        if (!preg_match('{^#(\d+) (.+)$}', $line, $matches)) {
+            return;
+        }
+
+        $id = (int) $matches[1];
+        $rest = $matches[2];
+
+        if (preg_match('{^(DONE|CACHED|ERROR|CANCELED)\b}', $rest)) {
+            unset($build['active'][$id]);
+        } elseif (!isset($build['steps'][$id])) {
+            $build['steps'][$id] = $rest;
+            $build['active'][$id] = true;
+        }
+    }
+
+    public function tick(): void
+    {
+        $now = microtime(true);
+
+        if ($now - $this->renderedAt < self::REFRESH) {
+            return;
+        }
+
+        $this->renderedAt = $now;
+        $this->section->overwrite($this->lines($now));
+    }
+
+    public function finish(string $service, bool $successful): void
+    {
+        $build = &$this->builds[$service];
+        $build['end'] = microtime(true);
+        $build['successful'] = $successful;
+    }
+
+    public function end(): void
+    {
+        $this->section->overwrite($this->lines(microtime(true)));
+
+        foreach ($this->builds as $service => $build) {
+            if (false !== $build['successful']) {
+                continue;
+            }
+
+            $this->output->writeln('');
+            $this->output->writeln(\sprintf('<fg=red>%s</>', $service));
+
+            foreach ($build['log'] as $line) {
+                $this->output->writeln(OutputFormatter::escape($line));
+            }
+        }
+    }
+
+    /**
+     * @return list<string>
+     */
+    public function lines(float $now): array
+    {
+        $frame = self::SPINNER[(int) ($now / self::SPIN) % \count(self::SPINNER)];
+        $columns = $this->terminalWidth ?? (new Terminal())->getWidth();
+        $lines = [];
+
+        foreach ($this->builds as $service => $build) {
+            $elapsed = \sprintf('%.1fs', ($build['end'] ?? $now) - $build['start']);
+
+            [$icon, $text] = match ($build['successful']) {
+                true => ['<fg=green>✔</>', 'built'],
+                false => ['<fg=red>✘</>', 'failed'],
+                null => ["<fg=yellow>{$frame}</>", $this->currentStep($build['steps'], $build['active'])],
+            };
+
+            // Icon, two spaces, the name, two spaces, the step, a space, the time.
+            $room = max(0, $columns - 1 - 2 - $this->width - 2 - 1 - \strlen($elapsed) - 1);
+            $text = Helper::width($text) > $room ? mb_substr($text, 0, max(0, $room - 1)) . '…' : $text;
+
+            $lines[] = \sprintf(
+                '%s  %s  %s %s<fg=gray>%s</>',
+                $icon,
+                str_pad($service, $this->width),
+                OutputFormatter::escape($text),
+                str_repeat(' ', max(0, $room - Helper::width($text))),
+                $elapsed,
+            );
+        }
+
+        return $lines;
+    }
+
+    /**
+     * @param array<int, string> $steps
+     * @param array<int, true>   $active
+     */
+    private function currentStep(array $steps, array $active): string
+    {
+        if ($active) {
+            return $steps[array_key_last($active)];
+        }
+
+        return $steps ? $steps[array_key_last($steps)] : 'starting';
+    }
+}

src/Build/BuildReporter.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Castor\Docker\Build;
+
+/**
+ * Shows several builds running at once, fed line by line.
+ */
+interface BuildReporter
+{
+    public function line(string $service, string $line): void;
+
+    /**
+     * Called every few milliseconds while the builds run, to animate what needs to be.
+     */
+    public function tick(): void;
+
+    public function finish(string $service, bool $successful): void;
+
+    public function end(): void;
+}

src/Build/StreamedBuildReporter.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Castor\Docker\Build;
+
+use Symfony\Component\Console\Formatter\OutputFormatter;
+use Symfony\Component\Console\Output\OutputInterface;
+
+/**
+ * Every line as it comes, prefixed by its service the way "docker compose
+ * logs" does: what a CI log, or any output that is not a terminal, can show.
+ */
+final class StreamedBuildReporter implements BuildReporter
+{
+    private const COLORS = ['cyan', 'yellow', 'green', 'magenta', 'blue', 'red'];
+
+    /** @var array<string, string> */
+    private array $prefixes = [];
+
+    /**
+     * @param non-empty-list<string> $services
+     */
+    public function __construct(private readonly OutputInterface $output, array $services)
+    {
+        $width = max(array_map(strlen(...), $services));
+
+        foreach ($services as $i => $service) {
+            $this->prefixes[$service] = \sprintf('<fg=%s>%s</> | ', self::COLORS[$i % \count(self::COLORS)], str_pad($service, $width));
+        }
+    }
+
+    public function line(string $service, string $line): void
+    {
+        $this->output->writeln($this->prefixes[$service] . OutputFormatter::escape($line));
+    }
+
+    public function tick(): void {}
+
+    public function finish(string $service, bool $successful): void {}
+
+    public function end(): void {}
+}

src/functions.php

@@ -77,11 +77,14 @@ function get_default_profiles(?Context $c = null): array
 }
 
 /**
+ * The command docker_compose() runs, and the context to run it in.
+ *
  * @param list<string> $subCommand
  * @param list<string> $profiles
- * @param ?string      $progress    "auto", "tty", "plain", "json" or "quiet", left to compose when null
+ *
+ * @return array{list<string>, Context}
  */
-function docker_compose(array $subCommand, ?Context $c = null, array $profiles = [], ?string $progress = null): Process
+function docker_compose_command(array $subCommand, ?Context $c = null, array $profiles = [], ?string $progress = null): array
 {
     $c ??= context();
     $profiles = $profiles ?: get_default_profiles($c);
@@ -120,6 +123,18 @@ function docker_compose(array $subCommand, ?Context $c = null, array $profiles =
 
     $command = array_merge($command, $subCommand);
 
+    return [$command, $c];
+}
+
+/**
+ * @param list<string> $subCommand
+ * @param list<string> $profiles
+ * @param ?string      $progress    "auto", "tty", "plain", "json" or "quiet", left to compose when null
+ */
+function docker_compose(array $subCommand, ?Context $c = null, array $profiles = [], ?string $progress = null): Process
+{
+    [$command, $c] = docker_compose_command($subCommand, $c, $profiles, $progress);
+
     // The router is not a service of this file: it joins the project network
     // from the outside, so it is attached after "up" and detached before "down".
     $network = get_project_network($c);