Replace contentful backend with github

Closes gh-21

Author: mbhave

README.adoc

@@ -2,9 +2,9 @@
 
 Spring projects are listed and documented on the spring.io website. 
 We can find there information about releases, samples, support and more.
-These projects are managed in Contentful.
+These projects are managed in Github.
 
-This project provides a RESTful web layer on top of Contentful's API for fetching and updating Spring Project Metadata. 
+This project provides a RESTful web layer on top of Github's API for fetching and updating Spring Project Metadata.
 It uses hypermedia to describe the relationships between resources and to allow navigation between them.
 
 ## Running the app locally
@@ -14,14 +14,11 @@ Configure the application with the following properties:
 [source,yaml]
 ----
 projects:
-  contentful:
-    access-token: 
-    content-management-token:
-    space-id:
-    environment-id:
   github:
     org:
     team:
+    accessToken:
+    branch:
 ----
 
 Build the application with `./gradlew build`.

build.gradle

@@ -42,6 +42,9 @@ dependencies {
 	implementation 'org.springframework.boot:spring-boot-starter-graphql'
 	implementation 'com.azure.spring:spring-cloud-azure-starter-keyvault-secrets'
 	implementation 'com.contentful.java:cma-sdk:3.4.12'
+	implementation 'com.fasterxml.jackson.datatype:jackson-datatype-jsr310'
+	implementation 'com.vladsch.flexmark:flexmark-all:0.64.8'
+	implementation 'org.apache.maven:maven-artifact:3.6.3'
 	testImplementation 'com.squareup.okhttp3:mockwebserver'
 	testImplementation 'org.springframework.boot:spring-boot-starter-test'
 	testImplementation 'org.springframework.graphql:spring-graphql-test'

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

@@ -18,11 +18,14 @@
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import io.spring.projectapi.ApplicationProperties.Contentful;
+import io.spring.projectapi.ApplicationProperties.Github;
 import io.spring.projectapi.contentful.ContentfulService;
+import io.spring.projectapi.github.GithubOperations;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.web.client.RestTemplateBuilder;
 import org.springframework.context.annotation.Bean;
 import org.springframework.web.reactive.function.client.WebClient;
 
@@ -46,6 +49,15 @@ public ContentfulService contentfulService(ObjectMapper objectMapper, WebClient.
 				environmentId);
 	}
 
+	@Bean
+	public GithubOperations githubOperations(RestTemplateBuilder builder, ObjectMapper objectMapper,
+			ApplicationProperties properties) {
+		Github github = properties.getGithub();
+		String accessToken = github.getAccesstoken();
+		String branch = github.getBranch();
+		return new GithubOperations(builder, objectMapper, accessToken, branch);
+	}
+
 	public static void main(String[] args) {
 		SpringApplication.run(Application.class, args);
 	}

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

@@ -124,10 +124,22 @@ public static class Github {
 		 */
 		private String team;
 
+		/**
+		 * Github access token for accessing the API.
+		 */
+		private String accesstoken;
+
+		/**
+		 * Github branch to use for fetching and updating content.
+		 */
+		private String branch;
+
 		@ConstructorBinding
-		Github(String org, String team) {
+		Github(String org, String team, String accesstoken, @DefaultValue("main") String branch) {
 			this.org = org;
 			this.team = team;
+			this.accesstoken = accesstoken;
+			this.branch = branch;
 		}
 
 		public String getOrg() {
@@ -138,6 +150,14 @@ public String getTeam() {
 			return this.team;
 		}
 
+		public String getBranch() {
+			return this.branch;
+		}
+
+		public String getAccesstoken() {
+			return this.accesstoken;
+		}
+
 	}
 
 }

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

@@ -0,0 +1,34 @@
+/*
+ * 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;
+
+/**
+ * {@link RuntimeException} indicating a problem with Github.
+ *
+ * @author Madhura Bhave
+ */
+public class GithubException extends RuntimeException {
+
+	GithubException(String message) {
+		super(message);
+	}
+
+	GithubException(Throwable cause) {
+		super(cause);
+	}
+
+}