Merge branch 'release/0.0.7'

README.md

@@ -9,21 +9,22 @@
 Export your favorite GitHub repositories to Prometheus
 
 * Use it _as a service_: See https://gh.skuzzle.de for instructions
-* Deploy it _on-premise_: `docker pull ghcr.io/skuzzle/gh-prom-exporter/gh-prom-exporter:0.0.6`
+* Deploy it _on-premise_: `docker pull ghcr.io/skuzzle/gh-prom-exporter/gh-prom-exporter:0.0.7`
 
 ## On-Premise deployment with docker
 This application can easily be run as a docker container in whatever environment you like:
 
 ```
 docker run -p 8080:8080 \
     -e WEB_ALLOWANONYMOUSSCRAPE=true \
-    ghcr.io/skuzzle/gh-prom-exporter/gh-prom-exporter:0.0.6
+    ghcr.io/skuzzle/gh-prom-exporter/gh-prom-exporter:0.0.7
 ```
 
 With _anonymous scraping_ allowed, you can now easily view the scrape results directly in the browser by navigating to
-`https://your.docker.host:8080/YOUR-GITHUB-USERNAME/YOUR-REPOSITORY`.
+`http://localhost:8080/YOUR-GITHUB-USERNAME/YOUR-REPOSITORY`.
 
-The scraped repository can just as easy be added as static scrape target to your prometheus' scrape configs: 
+The scraped repository can just as easily be added as static scrape target to your prometheus' scrape configs. You can
+also scrape multiple repositories of the same owner at once: 
 
 ```
 scrape_configs:
@@ -37,10 +38,10 @@ scrape_configs:
 In case you want to enforce authenticated scrapes only, use this configuration instead:
 ```
 docker run -p 8080:8080 \
-    ghcr.io/skuzzle/gh-prom-exporter/gh-prom-exporter:0.0.6
+    ghcr.io/skuzzle/gh-prom-exporter/gh-prom-exporter:0.0.7
 ```
 
-And
+Scraping now requires a GitHub access token, otherwise the service will respond with 401/Unauthorized. 
 
 ```
 scrape_configs:

RELEASE_NOTES.md

@@ -2,8 +2,8 @@
 
 [![Coverage Status](https://coveralls.io/repos/github/skuzzle/gh-prom-exporter/badge.svg?branch=master)](https://coveralls.io/github/skuzzle/gh-prom-exporter?branch=master) [![Twitter Follow](https://img.shields.io/twitter/follow/skuzzleOSS.svg?style=social)](https://twitter.com/skuzzleOSS)
 
-* Display application version
+* Support open metrics format (`Accept: application/openmetrics-text`)
 
 ```
-docker pull ghcr.io/skuzzle/gh-prom-exporter/gh-prom-exporter:0.0.6
+docker pull ghcr.io/skuzzle/gh-prom-exporter/gh-prom-exporter:0.0.7
 ```

pom.xml

@@ -11,7 +11,7 @@
 
     <groupId>de.skuzzle.ghpromexporter</groupId>
     <artifactId>gh-prom-exporter</artifactId>
-    <version>0.0.6</version>
+    <version>0.0.7</version>
 
     <name>gh-prom-exporter</name>
     <description>Export GitHub repository metrics in prometheus format</description>

readme/README.md

@@ -21,9 +21,10 @@ docker run -p 8080:8080 \
 ```
 
 With _anonymous scraping_ allowed, you can now easily view the scrape results directly in the browser by navigating to
-`https://your.docker.host:8080/YOUR-GITHUB-USERNAME/YOUR-REPOSITORY`.
+`http://localhost:8080/YOUR-GITHUB-USERNAME/YOUR-REPOSITORY`.
 
-The scraped repository can just as easy be added as static scrape target to your prometheus' scrape configs: 
+The scraped repository can just as easily be added as static scrape target to your prometheus' scrape configs. You can
+also scrape multiple repositories of the same owner at once: 
 
 ```
 scrape_configs:
@@ -40,7 +41,7 @@ docker run -p 8080:8080 \
     ${docker.image.name}:${project.version}
 ```
 
-And
+Scraping now requires a GitHub access token, otherwise the service will respond with 401/Unauthorized. 
 
 ```
 scrape_configs:

readme/RELEASE_NOTES.md

@@ -2,7 +2,7 @@
 
 [![Coverage Status](https://coveralls.io/repos/github/${github.user}/${github.name}/badge.svg?branch=${github.main-branch})](https://coveralls.io/github/${github.user}/${github.name}?branch=${github.main-branch}) [![Twitter Follow](https://img.shields.io/twitter/follow/skuzzleOSS.svg?style=social)](https://twitter.com/skuzzleOSS)
 
-* Display application version
+* Support open metrics format (`Accept: application/openmetrics-text`)
 
 ```
 docker pull ${docker.image.name}:${project.version}

src/main/java/de/skuzzle/ghpromexporter/web/MultipleRepositories.java

@@ -25,4 +25,9 @@ Flux<ScrapeRepositoryRequest> requests() {
         return Flux.fromStream(repositories.stream()
                 .map(repository -> ScrapeRepositoryRequest.of(owner, repository)));
     }
+
+    @Override
+    public String toString() {
+        return "owner=%s, repositories=%s".formatted(owner, repositories);
+    }
 }

src/main/java/de/skuzzle/ghpromexporter/web/PromController.java

@@ -2,6 +2,8 @@
 
 import java.net.InetAddress;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
@@ -25,6 +27,8 @@ record PromController(
         AbuseLimiter abuseLimiter,
         WebProperties properties) {
 
+    private static final Logger log = LoggerFactory.getLogger(PromController.class);
+
     @GetMapping(path = "{owner}/{repositories}")
     public Mono<ResponseEntity<String>> createStats(
             @PathVariable String owner,
@@ -39,9 +43,10 @@ public Mono<ResponseEntity<String>> createStats(
         }
 
         final InetAddress origin = request.getRemoteAddress().getAddress();
-        final MediaType contentType = MediaType.TEXT_PLAIN;// determineContentType(request);
+        final MediaType contentType = determineContentType(request);
 
         final MultipleRepositories multipleRepositories = MultipleRepositories.parse(owner, repositories);
+        log.info("Request from '{}' to scrape '{}'", gitHubAuthentication, multipleRepositories);
 
         return abuseLimiter.blockAbusers(origin)
                 .flatMap(__ -> freshResponse(gitHubAuthentication, multipleRepositories, contentType))
@@ -53,6 +58,10 @@ public Mono<ResponseEntity<String>> createStats(
                                 .body("Your IP '%s' has exceeded the abuse limit\n".formatted(origin))));
     }
 
+    private MediaType determineContentType(ServerHttpRequest request) {
+        return serializer.determineMediaType(request.getHeaders().getAccept());
+    }
+
     private Mono<ResponseEntity<String>> freshResponse(GitHubAuthentication authentication,
             MultipleRepositories repositories, MediaType contentType) {
 

src/main/java/de/skuzzle/ghpromexporter/web/RegistrySerializer.java

@@ -2,30 +2,91 @@
 
 import java.io.IOException;
 import java.io.StringWriter;
+import java.io.Writer;
+import java.util.Collection;
+import java.util.Enumeration;
+import java.util.List;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.http.MediaType;
 import org.springframework.stereotype.Component;
 
+import io.prometheus.client.Collector;
+import io.prometheus.client.Collector.MetricFamilySamples;
 import io.prometheus.client.CollectorRegistry;
 import io.prometheus.client.exporter.common.TextFormat;
 
 @Component
 class RegistrySerializer {
 
-    private static final MediaType OPEN_METRICS = MediaType
+    private static final Logger log = LoggerFactory.getLogger(RegistrySerializer.class);
+
+    static final MediaType OPEN_METRICS = MediaType
             .parseMediaType("application/openmetrics-text; version=1.0.0; charset=utf-8");
 
+    static final MediaType FORMAT_004 = MediaType.parseMediaType("text/plain; version=0.0.4; charset=utf-8");
+
+    private final List<Serializer> serializers = List.of(new V004(), new OpenMetrics());
+
+    public MediaType determineMediaType(Collection<MediaType> acceptibleMediaTypes) {
+        final MediaType result = serializers.stream()
+                .filter(serializer -> acceptibleMediaTypes.stream()
+                        .anyMatch(acceptible -> serializer.supportedMediaType().isCompatibleWith(acceptible)))
+                .findFirst()
+                .map(Serializer::supportedMediaType)
+                .orElse(FORMAT_004);
+
+        log.debug("Chose '{}' from acceptible meda types {}", result, acceptibleMediaTypes);
+        return result;
+    }
+
     public String serializeRegistry(CollectorRegistry registry, MediaType mediaType) {
         try (final var stringWriter = new StringWriter()) {
-            if (mediaType.isCompatibleWith(OPEN_METRICS)) {
-                TextFormat.writeOpenMetrics100(stringWriter, registry.metricFamilySamples());
-            } else {
-                TextFormat.write004(stringWriter, registry.metricFamilySamples());
-            }
+            serializers.stream()
+                    .filter(serializer -> serializer.supportedMediaType().equals(mediaType))
+                    .findFirst()
+                    .orElseThrow()
+                    .write(stringWriter, registry.metricFamilySamples());
+
             return stringWriter.toString();
         } catch (final IOException e) {
             throw new IllegalStateException("Error while serializing registry", e);
         }
     }
 
+    private interface Serializer {
+
+        MediaType supportedMediaType();
+
+        void write(Writer writer, Enumeration<Collector.MetricFamilySamples> mfs) throws IOException;
+    }
+
+    private static class OpenMetrics implements Serializer {
+
+        @Override
+        public MediaType supportedMediaType() {
+            return OPEN_METRICS;
+        }
+
+        @Override
+        public void write(Writer writer, Enumeration<MetricFamilySamples> mfs) throws IOException {
+            TextFormat.writeOpenMetrics100(writer, mfs);
+        }
+
+    }
+
+    private static final class V004 implements Serializer {
+
+        @Override
+        public MediaType supportedMediaType() {
+            return FORMAT_004;
+        }
+
+        @Override
+        public void write(Writer writer, Enumeration<MetricFamilySamples> mfs) throws IOException {
+            TextFormat.write004(writer, mfs);
+        }
+
+    }
 }