Merge pull request #239 from dmarmugi/feature/addScheme

Issue #231: Add __scheme__ configuration

docs/config.md

@@ -556,6 +556,11 @@ Specifies the port number of the host (or the IP address) which shall be used fo
 
 Setting this option is optional. If not specified, Promregator tries to auto-detect this value based on the configuration of the underlying operating system and the request, which triggered the service discovery.
 
+#### Option "promregator.discovery.scheme" (optional)
+Specifies the scheme (`http|https`) of the host (or the IP address) which shall be used for specifying the target during discovery. As a rule of thumb, this name should always be the scheme under which Prometheus is capable of reaching Promregator.
+
+Setting this option is optional. If not specified, and `promregator.discovery.port` is set to `443`, Promregator sets this to `https`. This is output as `__scheme__` in the target labels. 
+
 #### Option "promregator.discovery.auth" (optional)
 Specifies the way how authentication shall be verified, if a request reaches the endpoint. Valid values are:
 

src/main/java/org/cloudfoundry/promregator/endpoint/DiscoveryEndpoint.java

@@ -35,6 +35,9 @@ public class DiscoveryEndpoint {
 	@Value("${promregator.discovery.hostname:#{null}}")
 	private String myHostname;
 
+	@Value("${promregator.discovery.scheme:#{null}}")
+	private String myScheme;
+
 	@Value("${promregator.discovery.port:0}")
 	private int myPort;
 
@@ -49,14 +52,16 @@ public static class DiscoveryLabel {
 		private String applicationId;
 		private String instanceNumber;
 		private String instanceId;
+		private String scheme;
 
-		public DiscoveryLabel(String path) {
+		public DiscoveryLabel(String path, String scheme) {
 			super();
 			this.targetPath = path;
+			this.scheme = scheme;
 		}
 
-		public DiscoveryLabel(String path, Instance instance) {
-			this(path);
+		public DiscoveryLabel(String path, String scheme, Instance instance) {
+			this(path, scheme);
 
 			this.orgName = instance.getTarget().getOrgName();
 			this.spaceName = instance.getTarget().getSpaceName();
@@ -105,6 +110,11 @@ public String getInstanceId() {
 		public String getMetricsPath() {
 			return this.targetPath;
 		}
+
+		@JsonGetter("__scheme__")
+		public String getScheme() {
+			return this.scheme;
+		}
 	}
 
 	public static class DiscoveryResponse {
@@ -138,6 +148,9 @@ public ResponseEntity<DiscoveryResponse[]> getDiscovery(HttpServletRequest reque
 
 		String localHostname = this.myHostname != null ? this.myHostname : request.getLocalName();
 		int localPort = this.myPort != 0 ? this.myPort : request.getLocalPort();
+
+		//Default __scheme__ to https if promregator.discovery.port:443
+		String localScheme = (this.myScheme == null && this.myPort == 443) ? "https" : this.myScheme;
 		final String[] targets = { String.format("%s:%d", localHostname, localPort) };
 
 		log.info("Using scraping target {} in discovery response", targets[0]);
@@ -146,15 +159,15 @@ public ResponseEntity<DiscoveryResponse[]> getDiscovery(HttpServletRequest reque
 		for (Instance instance : instances) {
 
 			String path = String.format(EndpointConstants.ENDPOINT_PATH_SINGLE_TARGET_SCRAPING+"/%s/%s", instance.getApplicationId(), instance.getInstanceNumber());
-			DiscoveryLabel dl = new DiscoveryLabel(path, instance);
+			DiscoveryLabel dl = new DiscoveryLabel(path, localScheme, instance);
 
 			DiscoveryResponse dr = new DiscoveryResponse(targets, dl);
 			result.add(dr);
 		}
 
 		if (this.promregatorMetricsEndpoint) {
 			// finally, also add our own metrics endpoint
-			DiscoveryLabel dl = new DiscoveryLabel(EndpointConstants.ENDPOINT_PATH_PROMREGATOR_METRICS);
+			DiscoveryLabel dl = new DiscoveryLabel(EndpointConstants.ENDPOINT_PATH_PROMREGATOR_METRICS, localScheme);
 			result.add(new DiscoveryResponse(targets, dl));
 		}
 

src/test/java/org/cloudfoundry/promregator/endpoint/DiscoveryEndpointTest.java

@@ -15,6 +15,10 @@
 import org.springframework.http.ResponseEntity;
 import org.springframework.test.context.TestPropertySource;
 import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.test.util.ReflectionTestUtils;
+
+import java.sql.Ref;
+import java.util.Arrays;
 
 
 @ExtendWith(SpringExtension.class)
@@ -91,4 +95,52 @@ void testStraightForward() {
 
 	}
 
+	@Test
+	void testSchemePropertySetsSchemeInOutput(){
+		//given promregator.discovery.port:443 and promregator.discovery.scheme unset
+		ReflectionTestUtils.setField(subject, "myScheme", "https");
+
+		//when getDiscovery
+		HttpServletRequest requestMock = Mockito.mock(HttpServletRequest.class);
+		ResponseEntity<DiscoveryResponse[]> responseE = this.subject.getDiscovery(requestMock);
+		DiscoveryResponse[] responses = responseE.getBody();
+
+		//then response labels contain __scheme__: https
+		Assertions.assertTrue(Arrays.stream(responses).allMatch(
+			response -> "https".equals(response.getLabels().getScheme())
+		));
+	}
+
+	@Test
+	void testPort443SetsHttpsIfSchemeNotSet(){
+		//given promregator.discovery.port:443 and promregator.discovery.scheme unset
+		ReflectionTestUtils.setField(subject, "myPort", 443);
+
+		//when getDiscovery
+		HttpServletRequest requestMock = Mockito.mock(HttpServletRequest.class);
+		ResponseEntity<DiscoveryResponse[]> responseE = this.subject.getDiscovery(requestMock);
+		DiscoveryResponse[] responses = responseE.getBody();
+
+		//then response labels contain __scheme__: https
+		Assertions.assertTrue(Arrays.stream(responses).allMatch(
+			response -> "https".equals(response.getLabels().getScheme())
+		));
+	}
+
+	@Test
+	void testPort443DoesntSetHttpsIfSchemeIsExplicitlySetToHttp(){
+		//given promregator.discovery.port:443 and promregator.discovery.scheme unset
+		ReflectionTestUtils.setField(subject, "myPort", 443);
+		ReflectionTestUtils.setField(subject, "myScheme", "http");
+
+		//when getDiscovery
+		HttpServletRequest requestMock = Mockito.mock(HttpServletRequest.class);
+		ResponseEntity<DiscoveryResponse[]> responseE = this.subject.getDiscovery(requestMock);
+		DiscoveryResponse[] responses = responseE.getBody();
+
+		//then response labels contain __scheme__: https
+		Assertions.assertTrue(Arrays.stream(responses).allMatch(
+			response -> "http".equals(response.getLabels().getScheme())
+		));
+	}
 }