Retry project documentation add/delete if conflict

Closes gh-25

build.gradle

@@ -41,6 +41,7 @@ dependencies {
 	implementation 'org.springframework.boot:spring-boot-starter-oauth2-resource-server'
 	implementation 'org.springframework.boot:spring-boot-starter-hateoas'
 	implementation 'org.springframework.boot:spring-boot-starter-graphql'
+	implementation 'org.springframework.retry:spring-retry:2.0.10'
 	implementation 'com.azure.spring:spring-cloud-azure-starter-keyvault-secrets'
 	implementation 'com.fasterxml.jackson.datatype:jackson-datatype-jsr310'
 	implementation 'jakarta.xml.bind:jakarta.xml.bind-api:4.0.2'

src/main/java/io/spring/projectapi/Application.java

@@ -26,18 +26,20 @@
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.web.client.RestTemplateBuilder;
 import org.springframework.context.annotation.Bean;
+import org.springframework.retry.support.RetryTemplate;
+import org.springframework.web.client.HttpClientErrorException;
 
 @SpringBootApplication
 @EnableConfigurationProperties(ApplicationProperties.class)
 public class Application {
 
 	@Bean
 	public GithubOperations githubOperations(RestTemplateBuilder builder, ObjectMapper objectMapper,
-			ApplicationProperties properties) {
+			ApplicationProperties properties, RetryTemplate retryTemplate) {
 		Github github = properties.getGithub();
 		String accessToken = github.getAccesstoken();
 		String branch = github.getBranch();
-		return new GithubOperations(builder, objectMapper, accessToken, branch);
+		return new GithubOperations(builder, objectMapper, accessToken, branch, retryTemplate);
 	}
 
 	@Bean
@@ -49,6 +51,16 @@ public GithubQueries githubQueries(RestTemplateBuilder builder, ObjectMapper obj
 		return new GithubQueries(builder, objectMapper, accessToken, branch);
 	}
 
+	@Bean
+	public RetryTemplate retryTemplate() {
+		return RetryTemplate.builder().maxAttempts(10).exponentialBackoff(100, 2, 10000).retryOn((throwable) -> {
+			if (throwable instanceof HttpClientErrorException ex) {
+				return (ex.getStatusCode().value() == 409);
+			}
+			return false;
+		}).build();
+	}
+
 	public static void main(String[] args) {
 		SpringApplication.run(Application.class, args);
 	}

src/main/java/io/spring/projectapi/github/ConflictingGithubContentException.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.projectapi.github;
+
+import org.springframework.web.client.HttpClientErrorException;
+
+/**
+ * {@link GithubException} thrown when an update results in a conflict.
+ *
+ * @author Madhura Bhave
+ */
+public class ConflictingGithubContentException extends GithubException {
+
+	ConflictingGithubContentException(String projectSlug, String fileName) {
+		super("Conflicting update for slug '%s' and file %s".formatted(projectSlug, fileName));
+	}
+
+	static void throwIfConflict(HttpClientErrorException ex, String projectSlug, String fileName) {
+		if (ex.getStatusCode().value() == 409) {
+			throw new ConflictingGithubContentException(projectSlug, fileName);
+		}
+	}
+
+}

src/main/java/io/spring/projectapi/github/GithubOperations.java

@@ -44,6 +44,7 @@
 import org.springframework.http.MediaType;
 import org.springframework.http.RequestEntity;
 import org.springframework.http.ResponseEntity;
+import org.springframework.retry.support.RetryTemplate;
 import org.springframework.util.StringUtils;
 import org.springframework.web.client.HttpClientErrorException;
 import org.springframework.web.client.RestTemplate;
@@ -84,8 +85,11 @@ public class GithubOperations {
 
 	private final String branch;
 
+	private final RetryTemplate retryTemplate;
+
 	public GithubOperations(RestTemplateBuilder restTemplateBuilder, ObjectMapper objectMapper, String token,
-			String branch) {
+			String branch, RetryTemplate retryTemplate) {
+		this.retryTemplate = retryTemplate;
 		this.restTemplate = restTemplateBuilder.rootUri(GITHUB_URI)
 			.defaultHeader("Authorization", "Bearer " + token)
 			.build();
@@ -102,17 +106,26 @@ private static int compare(ProjectDocumentation o1, ProjectDocumentation o2) {
 	}
 
 	public void addProjectDocumentation(String projectSlug, ProjectDocumentation documentation) {
-		ResponseEntity<Map<String, Object>> response = getFile(projectSlug, "documentation.json");
-		List<ProjectDocumentation> documentations = new ArrayList<>();
-		String sha = null;
-		if (response != null) {
-			String content = getFileContents(response);
-			sha = getFileSha(response);
-			documentations.addAll(convertToProjectDocumentation(content));
+		try {
+			this.retryTemplate.execute((context) -> {
+				ResponseEntity<Map<String, Object>> response = getFile(projectSlug, "documentation.json");
+				List<ProjectDocumentation> documentations = new ArrayList<>();
+				String sha = null;
+				if (response != null) {
+					String content = getFileContents(response);
+					sha = getFileSha(response);
+					documentations.addAll(convertToProjectDocumentation(content));
+				}
+				documentations.add(documentation);
+				List<ProjectDocumentation> updatedDocumentation = computeCurrentRelease(documentations);
+				updateProjectDocumentation(projectSlug, updatedDocumentation, sha);
+				return null;
+			});
 		}
-		documentations.add(documentation);
-		List<ProjectDocumentation> updatedDocumentation = computeCurrentRelease(documentations);
-		updateProjectDocumentation(projectSlug, updatedDocumentation, sha);
+		catch (HttpClientErrorException ex) {
+			ConflictingGithubContentException.throwIfConflict(ex, projectSlug, "documentation.json");
+		}
+
 	}
 
 	private List<ProjectDocumentation> convertToProjectDocumentation(String content) {
@@ -201,15 +214,25 @@ private static ProjectDocumentation updateCurrent(ProjectDocumentation documenta
 	}
 
 	public void deleteDocumentation(String projectSlug, String version) {
-		ResponseEntity<Map<String, Object>> response = getFile(projectSlug, "documentation.json");
-		NoSuchGithubFileFoundException.throwWhenFileNotFound(response, projectSlug, "documentation.json");
-		String content = getFileContents(response);
-		String sha = getFileSha(response);
-		List<ProjectDocumentation> documentation = convertToProjectDocumentation(content);
-		NoSuchGithubProjectDocumentationFoundException.throwIfHasNotPresent(documentation, projectSlug, version);
-		documentation.removeIf((y) -> y.getVersion().equals(version));
-		List<ProjectDocumentation> documentations1 = computeCurrentRelease(documentation);
-		updateProjectDocumentation(projectSlug, documentations1, sha);
+		try {
+			this.retryTemplate.execute((context) -> {
+				ResponseEntity<Map<String, Object>> response = getFile(projectSlug, "documentation.json");
+				NoSuchGithubFileFoundException.throwWhenFileNotFound(response, projectSlug, "documentation.json");
+				String content = getFileContents(response);
+				String sha = getFileSha(response);
+				List<ProjectDocumentation> documentation = convertToProjectDocumentation(content);
+				NoSuchGithubProjectDocumentationFoundException.throwIfHasNotPresent(documentation, projectSlug,
+						version);
+				documentation.removeIf((y) -> y.getVersion().equals(version));
+				List<ProjectDocumentation> documentations1 = computeCurrentRelease(documentation);
+				updateProjectDocumentation(projectSlug, documentations1, sha);
+				return null;
+			});
+		}
+		catch (HttpClientErrorException ex) {
+			ConflictingGithubContentException.throwIfConflict(ex, projectSlug, "documentation.json");
+		}
+
 	}
 
 	private ResponseEntity<Map<String, Object>> getFile(String projectSlug, String fileName) {

src/main/java/io/spring/projectapi/web/error/ExceptionAdvice.java

@@ -16,6 +16,7 @@
 
 package io.spring.projectapi.web.error;
 
+import io.spring.projectapi.github.ConflictingGithubContentException;
 import io.spring.projectapi.github.NoSuchGithubProjectDocumentationFoundException;
 import io.spring.projectapi.github.NoSuchGithubProjectException;
 
@@ -34,6 +35,8 @@ public class ExceptionAdvice {
 
 	private static final ResponseEntity<Object> NOT_FOUND = ResponseEntity.notFound().build();
 
+	private static final ResponseEntity<Object> CONFLICT = ResponseEntity.status(409).build();
+
 	@ExceptionHandler
 	private ResponseEntity<?> noSuchGithubProjectExceptionHandler(NoSuchGithubProjectException ex) {
 		return NOT_FOUND;
@@ -45,4 +48,9 @@ private ResponseEntity<?> noSuchGithubProjectDocumentationExceptionHandler(
 		return NOT_FOUND;
 	}
 
+	@ExceptionHandler
+	private ResponseEntity<?> conflictingGithubContentsExceptionHandler(ConflictingGithubContentException ex) {
+		return CONFLICT;
+	}
+
 }

src/test/java/io/spring/projectapi/ApplicationTests.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.projectapi;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.retry.backoff.ExponentialBackOffPolicy;
+import org.springframework.retry.support.RetryTemplate;
+import org.springframework.test.util.ReflectionTestUtils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Integration tests.
+ */
+@SpringBootTest
+class ApplicationTests {
+
+	@Autowired
+	private RetryTemplate retryTemplate;
+
+	@MockBean
+	private ProjectRepository projectRepository;
+
+	@Test
+	void retryTemplate() {
+		ExponentialBackOffPolicy backOffPolicy = (ExponentialBackOffPolicy) ReflectionTestUtils
+			.getField(this.retryTemplate, "backOffPolicy");
+		assertThat(ReflectionTestUtils.getField(backOffPolicy, "initialInterval")).isEqualTo(100L);
+		assertThat(ReflectionTestUtils.getField(backOffPolicy, "multiplier")).isEqualTo(2.0);
+		assertThat(ReflectionTestUtils.getField(backOffPolicy, "maxInterval")).isEqualTo(10000L);
+	}
+
+}

src/test/java/io/spring/projectapi/github/GithubOperationsTests.java

@@ -35,7 +35,9 @@
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
+import org.springframework.retry.support.RetryTemplate;
 import org.springframework.util.FileCopyUtils;
+import org.springframework.web.client.HttpClientErrorException;
 
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.springframework.test.web.client.match.MockRestRequestMatchers.jsonPath;
@@ -60,15 +62,27 @@ class GithubOperationsTests {
 
 	private static final String DOCUMENTATION_URI = "/project/test-project/documentation.json?ref=test";
 
+	private RetryTemplate retryTemplate;
+
 	@BeforeEach
 	void setup() {
 		this.customizer = new MockServerRestTemplateCustomizer();
 		ObjectMapper objectMapper = new ObjectMapper();
 		objectMapper.registerModule(new ParameterNamesModule(JsonCreator.Mode.PROPERTIES));
 		objectMapper.enable(SerializationFeature.INDENT_OUTPUT);
 		objectMapper.registerModule(new JavaTimeModule());
+		this.retryTemplate = getRetryTemplate();
 		this.operations = new GithubOperations(new RestTemplateBuilder(this.customizer), objectMapper, "test-token",
-				"test");
+				"test", this.retryTemplate);
+	}
+
+	private static RetryTemplate getRetryTemplate() {
+		return RetryTemplate.builder().maxAttempts(2).retryOn((throwable) -> {
+			if (throwable instanceof HttpClientErrorException ex) {
+				return ex.getStatusCode().value() == 409;
+			}
+			return false;
+		}).build();
 	}
 
 	@Test
@@ -78,6 +92,28 @@ void addProjectDocumentationWhenProjectDoesNotExistThrowsException() throws Exce
 			.addProjectDocumentation("does-not-exist", getDocumentation("1.0", Status.GENERAL_AVAILABILITY)));
 	}
 
+	@Test
+	void addProjectDocumentationWhenConflictShouldRetry() throws Exception {
+		setupFile("project-documentation-response.json", DOCUMENTATION_URI);
+		this.customizer.getServer().expect(method(HttpMethod.PUT)).andRespond(withStatus(HttpStatus.CONFLICT));
+		setupFile("project-documentation-response.json", DOCUMENTATION_URI);
+		setupFileUpdate("project-documentation-updated-content.json", "Update documentation",
+				"2d2f875ca7d476d8b01bc1db07d29b5eba1d5120");
+		ProjectDocumentation documentation = getDocumentation("3.15.1", Status.GENERAL_AVAILABILITY);
+		this.operations.addProjectDocumentation("test-project", documentation);
+	}
+
+	@Test
+	void addProjectDocumentationWhenConflictShouldThrowWhenRetriesFail() throws Exception {
+		setupFile("project-documentation-response.json", DOCUMENTATION_URI);
+		this.customizer.getServer().expect(method(HttpMethod.PUT)).andRespond(withStatus(HttpStatus.CONFLICT));
+		setupFile("project-documentation-response.json", DOCUMENTATION_URI);
+		this.customizer.getServer().expect(method(HttpMethod.PUT)).andRespond(withStatus(HttpStatus.CONFLICT));
+		ProjectDocumentation documentation = getDocumentation("3.15.1", Status.GENERAL_AVAILABILITY);
+		assertThatExceptionOfType(ConflictingGithubContentException.class)
+			.isThrownBy(() -> this.operations.addProjectDocumentation("test-project", documentation));
+	}
+
 	@Test
 	void addProjectDocumentation() throws Exception {
 		setupFile("project-documentation-response.json", DOCUMENTATION_URI);