[BUGFIX] Let syslog-ng take the messages of the services on Alpine

ci/image-tests/Checks/ContainerEnvironmentChecks.php

@@ -42,7 +42,8 @@ public function testTimeZoneFromTheEnvironment(): void
 
     /**
      * TZ=Europe/Berlin: cron runs a job for the current hour in Berlin, which is not the hour in UTC. The job comes from
-     * Hooks/ and is there before cron starts; the test works out its hours, see ImageTestCase::cronHours(). Only in the
+     * Hooks/ and is there before cron starts; the test works out its hours, see ImageTestCase::cronHours().
+     * SERVICE_CRON_OPTS: cron logs the job at its log level, through syslog-ng into the file of LOG_STDOUT. Only in the
      * images that start cron.
      */
     public function testCronRunsJobsInTheTimeZoneFromTheEnvironment(): void
@@ -56,6 +57,30 @@ public function testCronRunsJobsInTheTimeZoneFromTheEnvironment(): void
         $this->waitFor(function () use ($container): void {
             self::assertSame("ran\n", $this->stdout('cat /tmp/image-tests/cron-job 2>&1 || true', $container));
         }, 25, 3);
+        $this->waitFor(function () use ($container): void {
+            self::assertMatchesRegularExpression(
+                self::image()->isAlpine() ? '/crond\[\d+\]: USER root pid +\d+ cmd echo ran/' : '/CRON\[\d+\]: \(root\) END \(\[\d+\] echo ran/',
+                $this->stdout('cat ' . static::ENVIRONMENT['LOG_STDOUT'], $container),
+                'SERVICE_CRON_OPTS=' . self::cronOptions(),
+            );
+        }, 10, 1);
+    }
+
+    /**
+     * syslog-ng writes the messages of the programs in the container into the file of LOG_STDOUT. The environment
+     * container starts it where the image does not.
+     */
+    public function testSyslogMessagesReachTheFileFromTheEnvironment(): void
+    {
+        $container = $this->environmentContainer();
+        if (!in_array('syslog', self::services(), true)) {
+            $this->assertCommandSucceeds('docker-service enable syslog && docker-service start syslog', $container);
+        }
+
+        $this->eventually(function () use ($container): void {
+            $this->assertCommandSucceeds('logger -t image-test syslog-marker', $container);
+            self::assertStringContainsString('image-test: syslog-marker', $this->stdout('cat ' . static::ENVIRONMENT['LOG_STDOUT'], $container));
+        });
     }
 
     /**

ci/image-tests/Checks/ServiceChecks.php

@@ -13,8 +13,6 @@
 use function array_combine;
 use function array_keys;
 use function in_array;
-use function preg_grep;
-use function preg_quote;
 use function ksort;
 use function preg_match_all;
 use function sleep;
@@ -94,7 +92,7 @@ public static function serviceOptions(): iterable
     {
         yield 'supervisord' => ['supervisord'];
         foreach (self::services() as $service) {
-            if (in_array($service, ['cron', 'syslog', 'ssh', 'apache', 'php-fpm'], true)) {
+            if (in_array($service, ['syslog', 'ssh', 'apache', 'php-fpm'], true)) {
                 yield $service => [$service];
             }
         }
@@ -103,8 +101,8 @@ public static function serviceOptions(): iterable
     /**
      * What the SERVICE_*_OPTS of the environment container do: supervisord logs at the level "trace"; syslog-ng writes
      * its process id to the file of --pidfile; sshd listens on port 2222; Apache defines IMAGE_TEST, for which the
-     * configuration from Hooks/ sends a header; PHP-FPM names the session cookie IMAGETEST. Cron gets a log level of
-     * its own, which shows only in its command line.
+     * configuration from Hooks/ sends a header; PHP-FPM names the session cookie IMAGETEST. The log level of cron is
+     * checked by ContainerEnvironmentChecks.
      */
     #[DataProvider('serviceOptions')]
     public function testServiceOptionsFromTheEnvironment(string $service): void
@@ -129,10 +127,6 @@ public function testServiceOptionsFromTheEnvironment(string $service): void
                     'SERVICE_APACHE_OPTS=-DIMAGE_TEST',
                 ),
                 'php-fpm' => self::assertSame('IMAGETEST', $this->phpFpmBody($container, 'test=session_name'), 'SERVICE_PHPFPM_OPTS=-dsession.name=IMAGETEST'),
-                'cron' => self::assertNotSame([], preg_grep(
-                    '#^/usr/sbin/' . (self::image()->isAlpine() ? 'crond' : 'cron') . ' -f ' . preg_quote(self::cronOptions(), '#') . '$#',
-                    $this->commandLines($container),
-                ), 'SERVICE_CRON_OPTS'),
                 default => throw new LogicException('No check of the options of ' . $service),
             };
         });

ci/image-tests/ImageTestCase.php

@@ -310,11 +310,12 @@ protected function environmentContainer(): Container
     }
 
     /**
-     * A log level option of cron in Debian and Ubuntu, of BusyBox crond in Alpine.
+     * A log level option of cron in Debian and Ubuntu, of BusyBox crond in Alpine, at which cron logs each job it runs:
+     * Debian also logs its end, BusyBox its start.
      */
     protected static function cronOptions(): string
     {
-        return self::image()->isAlpine() ? '-l 8' : '-L 15';
+        return self::image()->isAlpine() ? '-l 0' : '-L 15';
     }
 
     /**

docker/base/alpine/conf/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };

docker/base/ubuntu-22.04/conf/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };

docker/php-official/8.2-alpine/conf/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };

docker/php-official/8.2/conf/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };

docker/php-official/8.3-alpine/conf/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };

docker/php-official/8.3/conf/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };

docker/php-official/8.4-alpine/conf/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };

docker/php-official/8.4/conf/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };

docker/php-official/8.5-alpine/conf/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };

docker/php-official/8.5/conf/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };

docs/environment-variables.md

@@ -35,7 +35,7 @@ Images: `base`, `base-app`, `apache`, `nginx`, `php-*`.
 | Variable | Default | Effect |
 | --- | --- | --- |
 | `CLI_SCRIPT` | not set | Command the `cli` entrypoint runs as `APPLICATION_USER`. Works in `base-app` and `php-*` only; in the other images `cli` fails because `APPLICATION_USER` is not set. See [Customization](customization.md#commands). |
-| `LOG_STDOUT` | container stdout | File that `/docker.stdout` points to. Nginx and Apache write their access logs there, syslog-ng the messages of the services, for example of cron and Postfix. PHP-FPM does not, see [Known issues](known-issues.md#log_stdout-and-log_stderr-for-php-fpm); on Alpine, syslog-ng gets no messages, see [syslog on Alpine](known-issues.md#syslog-on-alpine). |
+| `LOG_STDOUT` | container stdout | File that `/docker.stdout` points to. Nginx and Apache write their access logs there, syslog-ng the messages of the services, for example of cron and Postfix. PHP-FPM does not, see [Known issues](known-issues.md#log_stdout-and-log_stderr-for-php-fpm). |
 | `LOG_STDERR` | container stderr | File that `/docker.stderr` points to. Nginx and Apache write their error logs there. |
 | `TZ` | not set (UTC) | Time zone of the container, for example `Europe/Berlin`. It applies to `date`, cron and the time stamps supervisord writes to the container log. PHP uses `PHP_DATE_TIMEZONE` instead, see [Time zone](customization.md#time-zone). |
 

docs/known-issues.md

@@ -28,16 +28,6 @@ These options and tools are part of the images but do not work, or work only in
 - **Images:** `php-*`, Debian and Alpine.
 - **Instead:** Read them with `docker compose logs`. To have PHP-FPM's messages and the PHP errors in the file of `LOG_STDERR`, also set `fpm.global.error_log: /docker.stderr`. The access log needs a pool file that sorts after `docker.conf`, see [`fpm.pool.<key>`](#fpmpoolkey-for-the-directives-of-dockerconf).
 
-### syslog on Alpine
-
-- **Effect:** syslog-ng takes messages on `/dev/log` only as a stream, but programs on Alpine send them as datagrams. The messages of cron, Postfix and `logger` are lost: they reach neither the container log nor the file of `LOG_STDOUT`.
-- **Images:** the Alpine images that run syslog-ng: `php-*` with an `-alpine` tag, and `base`, `base-app`, `nginx` and `apache` once you enable the service.
-- **Instead:** Let syslog-ng take datagrams, in a [service hook](customization.md#service-hooks) such as `/opt/docker/bin/service.d/syslog-ng.d/50-dgram.sh`:
-
-  ```bash
-  sed -i 's#unix-stream("/dev/log")#unix-dgram("/dev/log")#' /opt/docker/etc/syslog-ng/syslog-ng.conf
-  ```
-
 ### No `/app` in `nginx` and `apache`
 
 - **Effect:** The images have no `/app`, the default document root. Without your application there, Nginx answers every request with `500` (`rewrite or internal redirection cycle`), and Apache exits at the start with `DocumentRoot '/app' is not a directory` and is restarted over and over.

provisioning/base/general/etc/syslog-ng/syslog-ng.conf

@@ -22,7 +22,8 @@ options {
 
 source s_src {
     # syslog-s_src START
-    unix-stream("/dev/log");
+    # a datagram socket: syslog() of glibc tries datagrams first, the one of musl on Alpine only sends datagrams
+    unix-dgram("/dev/log");
     internal();
     # syslog-s_src END
 };