diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6b0beb8..03457b9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 # `1.2.0` (unreleased)
 
+* Add a logger and enable `-v` and `-vv` options
 * Add the `--no-networks` and `--no-ports` options to avoid rendering networks and ports
 * Add the `--background` option to set the graph's background color
 * Versions correctly merged and checked
diff --git a/src/application.php b/src/application.php
index 1c402f1..db3dbb2 100644
--- a/src/application.php
+++ b/src/application.php
@@ -30,6 +30,7 @@ $application->register('render')
             throw new Console\Exception\InvalidArgumentException(sprintf('Invalid background color "%s". It must be a valid hex color or "transparent".', $backgroundColor));
         }
 
+        $logger = logger($output);
         $inputFile = $input->getArgument('input-file');
         $inputFileExtension = pathinfo($inputFile, PATHINFO_EXTENSION);
         $overrideFile = dirname($inputFile).DIRECTORY_SEPARATOR.basename($inputFile, '.'.$inputFileExtension).'.'.$input->getOption('override').'.'.$inputFileExtension;
@@ -52,10 +53,12 @@ $application->register('render')
             }
         }
 
+        $logger(sprintf('Reading <comment>configuration</comment> from <info>"%s"</info>', $inputFile));
         $configuration = readConfiguration($inputFile);
         $configurationVersion = (string) ($configuration['version'] ?? 1);
 
         if (!$input->getOption('ignore-override') && file_exists($overrideFile)) {
+            $logger(sprintf('Reading <comment>override</comment> from <info>"%s"</info>', $overrideFile));
             $override = readConfiguration($overrideFile);
             $overrideVersion = (string) ($override['version'] ?? 1);
 
@@ -64,14 +67,26 @@ $application->register('render')
             }
 
             $configuration = array_merge_recursive($configuration, $override);
+
+            $logger(sprintf('Configuration <comment>version</comment> is <info>"%s"</info>', $configurationVersion), Console\Output\OutputInterface::VERBOSITY_VERY_VERBOSE);
             $configuration['version'] = $configurationVersion;
         }
 
+        $logger('Fetching <comment>services</comment>');
         $services = fetchServices($configuration);
+        $logger(sprintf('Found <info>%d</info> <comment>services</comment>', count($services)), Console\Output\OutputInterface::VERBOSITY_VERY_VERBOSE);
+
+        $logger('Fetching <comment>volumes</comment>');
         $volumes = fetchVolumes($configuration);
+        $logger(sprintf('Found <info>%d</info> <comment>volumes</comment>', count($volumes)), Console\Output\OutputInterface::VERBOSITY_VERY_VERBOSE);
+
+        $logger('Fetching <comment>networks</comment>');
         $networks = fetchNetworks($configuration);
+        $logger(sprintf('Found <info>%d</info> <comment>networks</comment>', count($networks)), Console\Output\OutputInterface::VERBOSITY_VERY_VERBOSE);
 
         if ([] !== $onlyServices) {
+            $logger(sprintf('Only <info>%s</info> <comment>services</comment> will be displayed', implode(', ', $onlyServices)));
+
             $intersect = array_intersect($onlyServices, array_keys($services));
 
             if ($intersect !== $onlyServices) {
@@ -89,17 +104,24 @@ $application->register('render')
 
         $flags = 0;
         if ($input->getOption('no-volumes') === true) {
+            $logger('<comment>Volumes</comment> will not be displayed');
+
             $flags |= WITHOUT_VOLUMES;
         }
 
         if ($input->getOption('no-networks') === true) {
+            $logger('<comment>Networks</comment> will not be displayed');
+
             $flags |= WITHOUT_NETWORKS;
         }
 
         if ($input->getOption('no-ports') === true) {
+            $logger('<comment>Ports</comment> will not be displayed');
+
             $flags |= WITHOUT_PORTS;
         }
 
+        $logger('Rendering <comment>graph</comment>');
         $graph = applyGraphvizStyle(
             createGraph($services, $volumes, $networks, $inputFile, $flags),
             $input->getOption('horizontal'),
diff --git a/src/functions.php b/src/functions.php
index 4be8e12..6ca659f 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -5,6 +5,7 @@ namespace PMSIpilot\DockerComposeViz;
 use Fhaculty\Graph\Edge;
 use Fhaculty\Graph\Graph;
 use Fhaculty\Graph\Vertex;
+use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Yaml\Exception\ParseException;
 use Symfony\Component\Yaml\Yaml;
 
@@ -12,6 +13,20 @@ const WITHOUT_VOLUMES = 1;
 const WITHOUT_NETWORKS = 2;
 const WITHOUT_PORTS = 4;
 
+/**
+ * @internal
+ *
+ * @param OutputInterface $output
+ *
+ * @return callable
+ */
+function logger(OutputInterface $output) : callable
+{
+    return function (string $message, int $verbosity = null) use ($output) {
+        $output->writeln(sprintf('[%s] %s', date(DATE_ISO8601), $message), $verbosity ?: OutputInterface::VERBOSITY_VERBOSE);
+    };
+}
+
 /**
  * @public
  *
@@ -216,7 +231,7 @@ function makeVerticesAndEdges(Graph $graph, array $services, array $volumes, arr
     if (((bool) ($flags & WITHOUT_NETWORKS)) === false) {
         foreach ($networks as $network => $definition) {
             addNetwork(
-                $graph, 'net: ' . $network,
+                $graph, 'net: '.$network,
                 isset($definition['external']) && $definition['external'] === true ? 'external_network' : 'network'
             );
         }
@@ -318,7 +333,7 @@ function makeVerticesAndEdges(Graph $graph, array $services, array $volumes, arr
                 list($host, $container, $proto) = explodeMapping($port);
 
                 addRelation(
-                    addPort($graph, (int)$host, $proto),
+                    addPort($graph, (int) $host, $proto),
                     $graph->getVertex($service),
                     'ports',
                     $host !== $container ? $container : null
@@ -334,7 +349,7 @@ function makeVerticesAndEdges(Graph $graph, array $services, array $volumes, arr
 
                 addRelation(
                     $graph->getVertex($service),
-                    addNetwork($graph, 'net: ' . $network),
+                    addNetwork($graph, 'net: '.$network),
                     'networks',
                     count($aliases) > 0 ? implode(', ', $aliases) : null
                 );