OTLP/GRPC Exporter Implementation

.github/workflows/php.yml

@@ -25,7 +25,7 @@ jobs:
         php-version: ${{ matrix.php-versions }}
         coverage: xdebug
         tools: php-cs-fixer
-        extensions: ast
+        extensions: ast, grpc
 
     - name: Validate composer.json and composer.lock
       run: composer validate

.gitignore

@@ -6,7 +6,6 @@ vendor
 coverage.clover
 tests/coverage
 .php_cs.cache
-proto/*
 
 # W3C Test Service build artifacts
 tests/TraceContext/W3CTestService/test_app

.phan/config.php

@@ -309,6 +309,7 @@
     //       to `exclude_analysis_directory_list`.
     'exclude_analysis_directory_list' => [
         'vendor/',
+        'proto/',
     ],
 
     // Enable this to enable checks of require/include statements referring to valid paths.
@@ -360,6 +361,7 @@
         'Context',
         'sdk',
         'contrib',
+        'proto',
         'vendor/composer/xdebug-handler/src',
         'vendor/guzzlehttp',
         'vendor/psr',

.php_cs

@@ -2,6 +2,7 @@
 $finder = PhpCsFixer\Finder::create()
     ->exclude('vendor')
     ->exclude('var/cache')
+    ->exclude('proto')
     ->in(__DIR__);
 
 return PhpCsFixer\Config::create()

composer.json

@@ -9,7 +9,9 @@
         "guzzlehttp/guzzle": "^7.1.0",
         "psr/http-client": "^1.0",
         "php-http/guzzle7-adapter": "^0.1.1",
-        "promphp/prometheus_client_php": "^2.2.1"
+        "promphp/prometheus_client_php": "^2.2.1",
+        "grpc/grpc": "^1.30",
+        "google/protobuf": "^v3.3.0"
     },
     "authors": [
         {
@@ -30,7 +32,15 @@
             "OpenTelemetry\\Context\\": "Context",
             "OpenTelemetry\\": "api",
             "OpenTelemetry\\Sdk\\": "sdk",
-            "OpenTelemetry\\Contrib\\": "contrib"
+            "OpenTelemetry\\Contrib\\": "contrib",
+            "Opentelemetry\\Proto\\Collector\\Trace\\V1\\": "proto/Opentelemetry/Proto/Collector/Trace/V1",
+            "Opentelemetry\\Proto\\Trace\\V1\\":"proto/Opentelemetry/Proto/Trace/V1",
+            "Opentelemetry\\Proto\\Common\\V1\\":"proto/Opentelemetry/Proto/Common/V1",
+            "Opentelemetry\\Proto\\Resource\\V1\\":"proto/Opentelemetry/Proto/Resource/V1",
+            "GPBMetadata\\Opentelemetry\\Proto\\Collector\\Trace\\V1\\": "proto/GPBMetadata/Opentelemetry/Proto/Collector/Trace/V1",
+            "GPBMetadata\\Opentelemetry\\Proto\\Trace\\V1\\":"proto/GPBMetadata/Opentelemetry/Proto/Trace/V1",
+            "GPBMetadata\\Opentelemetry\\Proto\\Common\\V1\\":"proto/GPBMetadata/Opentelemetry/Proto/Common/V1",
+            "GPBMetadata\\Opentelemetry\\Proto\\Resource\\V1\\":"proto/GPBMetadata/Opentelemetry/Proto/Resource/V1"
         }
     },
     "autoload-dev": {

contrib/OtlpGrpc/Exporter.php

@@ -0,0 +1,204 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\OtlpGrpc;
+
+use grpc;
+use InvalidArgumentException;
+use Opentelemetry\Proto\Collector\Trace\V1\ExportTraceServiceRequest;
+use Opentelemetry\Proto\Collector\Trace\V1\TraceServiceClient;
+use OpenTelemetry\Sdk\Trace;
+use OpenTelemetry\Trace as API;
+
+class Exporter implements Trace\Exporter
+{
+    /**
+     * @var string
+     */
+    private $endpointURL;
+
+    /**
+     * @var string
+     */
+    private $protocol;
+
+    /**
+     * @var bool|string
+     */
+    private $insecure;
+
+    /**
+     * @var string
+     */
+    private $certificateFile;
+
+    /**
+     * @var string
+     */
+    private $headers;
+
+    /**
+     * @var bool|string
+     */
+    private $compression;
+
+    /**
+     * @var int
+     */
+    private $timeout;
+    /**
+     * @var SpanConverter
+     */
+    private $spanConverter;
+
+    private $metadata;
+
+    /**
+    * @var bool
+    */
+    private $running = true;
+
+    /**
+     * @var TraceServiceClient
+     */
+
+    private $client;
+
+    /**
+     * OTLP GRPC Exporter Constructor
+     */
+    public function __construct(
+        string $endpointURL = 'localhost:4317',
+        bool $insecure = true,
+        string $certificateFile = '',
+        string $headers = '',
+        bool $compression = false,
+        int $timeout = 10,
+        TraceServiceClient $client = null
+    ) {
+
+        // Set default values based on presence of env variable
+        $this->endpointURL = getenv('OTEL_EXPORTER_OTLP_ENDPOINT') ?: $endpointURL;
+        $this->protocol = getenv('OTEL_EXPORTER_OTLP_PROTOCOL') ?: 'grpc'; // I guess this is redundant?
+        $this->insecure = getenv('OTEL_EXPORTER_OTLP_INSECURE') ?: $insecure;
+        $this->certificateFile = getenv('OTEL_EXPORTER_OTLP_CERTIFICATE') ?: $certificateFile;
+        $this->headers = getenv('OTEL_EXPORTER_OTLP_HEADERS') ?: $headers;
+        $this->compression = getenv('OTEL_EXPORTER_OTLP_COMPRESSION') ?: $compression;
+        $this->timeout =(int) getenv('OTEL_EXPORTER_OTLP_TIMEOUT') ?: $timeout;
+
+        $this->spanConverter = new SpanConverter();
+
+        $this->metadata = $this->metadataFromHeaders($this->headers);
+
+        $opts = [
+            'update_metadata' => function () {
+                return $this->metadata;
+            },
+            'timeout' => $this->timeout,
+        ];
+
+        if (!$this->insecure && !$this->certificateFile) {
+            // Assumed default
+            $opts['credentials'] = Grpc\ChannelCredentials::createSsl('');
+        } elseif (!$this->insecure && $this->certificateFile !== '') {
+            // Should we validate more?
+            $opts['credentials'] = Grpc\ChannelCredentials::createSsl(file_get_contents($certificateFile));
+        } else {
+            $opts['credentials'] = Grpc\ChannelCredentials::createInsecure();
+        }
+
+        if ($this->compression) {
+            // gzip is the only specified compression method for now
+            $opts['grpc.default_compression_algorithm'] = 2;
+        }
+
+        $this->client = $client ?? new TraceServiceClient($this->endpointURL, $opts);
+    }
+
+    /**
+     * Exports the provided Span data via the OTLP protocol
+     *
+     * @param iterable<API\Span> $spans Array of Spans
+     * @return int return code, defined on the Exporter interface
+     */
+    public function export(iterable $spans): int
+    {
+        if (!$this->running) {
+            return Exporter::FAILED_NOT_RETRYABLE;
+        }
+
+        if (empty($spans)) {
+            return Trace\Exporter::SUCCESS;
+        }
+
+        $resourcespans = [$this->spanConverter->as_otlp_resource_span($spans)];
+
+        $request = new ExportTraceServiceRequest([
+            'resource_spans' => $resourcespans,
+        ]);
+
+        list($response, $status) = $this->client->Export($request)->wait();
+
+        if ($status->code == \Grpc\STATUS_OK) {
+            return Trace\Exporter::SUCCESS;
+        }
+
+        if (in_array($status->code, [
+            \Grpc\STATUS_CANCELLED,
+            \Grpc\STATUS_DEADLINE_EXCEEDED,
+            \Grpc\STATUS_PERMISSION_DENIED,
+            \Grpc\STATUS_RESOURCE_EXHAUSTED,
+            \Grpc\STATUS_ABORTED,
+            \Grpc\STATUS_OUT_OF_RANGE,
+            \Grpc\STATUS_UNAVAILABLE,
+            \Grpc\STATUS_DATA_LOSS,
+            \Grpc\STATUS_UNAUTHENTICATED,
+        ])) {
+            return Trace\Exporter::FAILED_RETRYABLE;
+        }
+
+        return Trace\Exporter::FAILED_NOT_RETRYABLE;
+    }
+
+    public function setHeader($key, $value)
+    {
+        $this->metadata[$key] = [$value];
+    }
+
+    public function getHeaders()
+    {
+        return $this->metadata;
+    }
+
+    public function metadataFromHeaders($headers): array
+    {
+        if (is_array($headers)) {
+            throw new InvalidArgumentException('Configuring Headers Via');
+        }
+
+        $pairs = explode(',', $headers);
+
+        if (!array_key_exists(1, $pairs)) {
+            return [];
+        }
+
+        $metadata = [];
+        foreach ($pairs as $pair) {
+            list($key, $value) = explode('=', $pair, 2);
+            $metadata[$key] = [$value];
+        }
+
+        return $metadata;
+    }
+
+    public function shutdown(): void
+    {
+        $this->running = false;
+    }
+
+    // public function getHeaders()
+    // {
+    //     return $this->metadataFromHeaders($this->headers);
+    // }
+}