feat : Github 소셜 로그인 추가 (#281)

* feat : github oauth code 받아 로그인하는 API 생성

* build : oauth-client 라이브러리 추가

* feat : User 필드로 githubName 추가

* feat : Github 소셜 로그인 및 Github 연동 구현

* feat : JwtAuthenticationFilter 대상에서 제외

* fix : access_token 파싱 실패 수정

* feat : OAuth2User에 불필요한 name 정보 제거

* refactor : getClaims 파라미터명 수정

* refactor : authority 값 수정

* refactor : 불필요한 상속 제거

* refactor : 유저 Github name 상시 동기화

* refactor : 유저 동기화 코드 early return 추가

* refactor : 메서드명 리팩토링

* feat : Github API 에러 시 로그 추가

* chore : github.yml 파일 import

build.gradle

@@ -62,6 +62,8 @@ dependencies {
     implementation 'com.fasterxml.jackson.core:jackson-databind:2.15.1'
     // Redis
     implementation 'org.springframework.boot:spring-boot-starter-data-redis'
+    // OAuth2
+    implementation 'org.springframework.boot:spring-boot-starter-oauth2-client'
 }
 
 clean {

prepare-build.sh

@@ -26,5 +26,6 @@ download_yml "jwt.yml"
 download_yml "mysql-dev.yml"
 download_yml "mysql-prod.yml"
 download_yml "webhook.yml"
+download_yml "github.yml"
 
 wait

src/main/java/com/gamzabat/algohub/auth/controller/OAuth2Controller.java

@@ -0,0 +1,31 @@
+package com.gamzabat.algohub.auth.controller;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.gamzabat.algohub.auth.service.OAuth2Service;
+import com.gamzabat.algohub.feature.user.dto.TokenResponse;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/api")
+@Tag(name = "oauth 소셜 로그인 관련 API", description = "code를 사용해 Github 소셜 로그인하는 API")
+public class OAuth2Controller {
+	private final OAuth2Service oAuth2Service;
+
+	@PostMapping("/oauth/github/sign-in")
+	@Operation(summary = "Github 소셜 로그인 API", description = "Github 소셜 로그인 후 발급된 code를 전달해 로그인하는 API")
+	public ResponseEntity<TokenResponse> signIn(@RequestParam String code) {
+		TokenResponse response = oAuth2Service.githubSignIn(code);
+		return ResponseEntity.ok(response);
+	}
+}

src/main/java/com/gamzabat/algohub/auth/dto/GithubEmailDto.java

@@ -0,0 +1,8 @@
+package com.gamzabat.algohub.auth.dto;
+
+import lombok.Getter;
+
+@Getter
+public class GithubEmailDto {
+	private String email;
+}

src/main/java/com/gamzabat/algohub/auth/dto/GithubUserDto.java

@@ -0,0 +1,11 @@
+package com.gamzabat.algohub.auth.dto;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class GithubUserDto {
+	private String login;
+	private String email;
+}

src/main/java/com/gamzabat/algohub/auth/dto/OAuthAccessTokenDto.java

@@ -0,0 +1,13 @@
+package com.gamzabat.algohub.auth.dto;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class OAuthAccessTokenDto {
+	@JsonProperty("access_token")
+	private String accessToken;
+}

src/main/java/com/gamzabat/algohub/auth/exception/GithubApiException.java

@@ -0,0 +1,10 @@
+package com.gamzabat.algohub.auth.exception;
+
+import lombok.Getter;
+
+@Getter
+public class GithubApiException extends RuntimeException {
+	public GithubApiException(String message) {
+		super(message);
+	}
+}

src/main/java/com/gamzabat/algohub/auth/service/OAuth2Service.java

@@ -0,0 +1,164 @@
+package com.gamzabat.algohub.auth.service;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.authority.SimpleGrantedAuthority;
+import org.springframework.security.oauth2.client.authentication.OAuth2AuthenticationToken;
+import org.springframework.security.oauth2.core.user.DefaultOAuth2User;
+import org.springframework.security.oauth2.core.user.OAuth2User;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestTemplate;
+
+import com.gamzabat.algohub.auth.dto.GithubEmailDto;
+import com.gamzabat.algohub.auth.dto.GithubUserDto;
+import com.gamzabat.algohub.auth.dto.OAuthAccessTokenDto;
+import com.gamzabat.algohub.auth.exception.GithubApiException;
+import com.gamzabat.algohub.common.jwt.TokenProvider;
+import com.gamzabat.algohub.common.jwt.dto.JwtDTO;
+import com.gamzabat.algohub.constants.ApiConstants;
+import com.gamzabat.algohub.enums.Role;
+import com.gamzabat.algohub.feature.user.domain.User;
+import com.gamzabat.algohub.feature.user.dto.TokenResponse;
+import com.gamzabat.algohub.feature.user.repository.UserRepository;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class OAuth2Service {
+	private final TokenProvider tokenProvider;
+	@Value("${github.client_id}")
+	private String clientId;
+	@Value("${github.client_secret}")
+	private String secretKey;
+	private final RestTemplate restTemplate;
+	private final UserRepository userRepository;
+
+	@Transactional
+	public TokenResponse githubSignIn(String code) {
+		String accessToken = getGithubAccessToken(code);
+		GithubUserDto githubUser = getGithubUserInfo(accessToken);
+		syncWithUser(githubUser);
+		Authentication authentication = createGithubAuthentication(githubUser);
+		JwtDTO tokens = tokenProvider.generateTokens(authentication);
+		return new TokenResponse(tokens.getAccessToken(), tokens.getRefreshToken());
+	}
+
+	private void syncWithUser(GithubUserDto githubUser) {
+		Optional<User> optionalUser = userRepository.findByEmail(githubUser.getEmail());
+		if (optionalUser.isEmpty()) {
+			register(githubUser);
+			return;
+		}
+		User user = optionalUser.get();
+		user.editGithubName(githubUser.getLogin());
+	}
+
+	private void register(GithubUserDto githubUser) {
+		User newUser = userRepository.save(User.builder()
+			.email(githubUser.getEmail())
+			.password(null)
+			.nickname(null)
+			.bjNickname(null)
+			.role(Role.USER)
+			.build());
+		newUser.editNickname(createTemporaryNickname(githubUser.getLogin(), newUser.getId()));
+		newUser.editGithubName(githubUser.getLogin());
+	}
+
+	private String createTemporaryNickname(String login, Long id) {
+		return login + "@" + id;
+	}
+
+	private String getGithubAccessToken(String code) {
+		HttpEntity<OAuthAccessTokenDto> response = restTemplate.exchange(
+			ApiConstants.GITHUB_ACCESS_TOKEN_URL,
+			HttpMethod.POST,
+			createAccessTokenRequest(code),
+			OAuthAccessTokenDto.class);
+
+		if (response.getBody() == null) {
+			log.error("failed to request GitHub access token : GitHub API response body is null.");
+			throw new GithubApiException("Github access token 응답에 실패했습니다.");
+		}
+
+		return response.getBody().getAccessToken();
+	}
+
+	private GithubUserDto getGithubUserInfo(String accessToken) {
+		ResponseEntity<GithubUserDto> response = restTemplate.exchange(
+			ApiConstants.GITHUB_USER_URL,
+			HttpMethod.GET,
+			createAuthorizationHeader(accessToken),
+			GithubUserDto.class);
+
+		GithubUserDto user = response.getBody();
+		if (user == null) {
+			log.error("failed to request GitHub user info : GitHub API response body is null.");
+			throw new GithubApiException("Github 사용자 정보를 가져오는데 실패했습니다.");
+		}
+
+		if (user.getEmail() == null || user.getEmail().isEmpty()) {
+			user.setEmail(getEmail(accessToken));
+		}
+
+		return user;
+	}
+
+	private String getEmail(String accessToken) {
+		ResponseEntity<List<GithubEmailDto>> emails = restTemplate.exchange(
+			ApiConstants.GITHUB_EMAIL_URL,
+			HttpMethod.GET,
+			createAuthorizationHeader(accessToken),
+			new ParameterizedTypeReference<>() {
+			}
+		);
+
+		if (emails.getBody() == null) {
+			log.error("failed to request GitHub user email : GitHub API response body is null.");
+			throw new GithubApiException("Github 유저의 이메일을 가져오는데 실패했습니다.");
+		}
+
+		return emails.getBody().getFirst().getEmail();
+	}
+
+	private Authentication createGithubAuthentication(GithubUserDto githubUser) {
+		OAuth2User oAuth2User = new DefaultOAuth2User(
+			Collections.singleton(new SimpleGrantedAuthority(Role.USER.toString())),
+			Map.of("email", githubUser.getEmail()),
+			"email"
+		);
+
+		return new OAuth2AuthenticationToken(oAuth2User, oAuth2User.getAuthorities(), "github");
+	}
+
+	private HttpEntity<MultiValueMap<String, String>> createAccessTokenRequest(String code) {
+		LinkedMultiValueMap<String, String> params = new LinkedMultiValueMap<>();
+		params.add("client_id", clientId);
+		params.add("client_secret", secretKey);
+		params.add("code", code);
+
+		return new HttpEntity<>(params, new HttpHeaders());
+	}
+
+	private HttpEntity<Map<String, String>> createAuthorizationHeader(String accessToken) {
+		HttpHeaders headers = new HttpHeaders();
+		headers.add("Authorization", "Bearer " + accessToken);
+		return new HttpEntity<>(headers);
+	}
+}

src/main/java/com/gamzabat/algohub/common/jwt/JwtAuthenticationFilter.java

@@ -30,7 +30,8 @@ public class JwtAuthenticationFilter extends OncePerRequestFilter {
 		"/api/auth/reissue-token",
 		"/api/users/check-email",
 		"/api/users/check-nickname",
-		"/api/users/check-baekjoon-nickname");
+		"/api/users/check-baekjoon-nickname",
+		"/api/oauth/github/sign-in");
 
 	@Override
 	protected boolean shouldNotFilter(HttpServletRequest request) throws ServletException {

src/main/java/com/gamzabat/algohub/common/jwt/TokenProvider.java

@@ -164,8 +164,8 @@ public String resolveToken(HttpServletRequest request) {
 		throw new JwtRequestException(HttpStatus.BAD_REQUEST.value(), "BAD_REQUEST", "유효한 형태의 토큰이 존재하지 않습니다.");
 	}
 
-	private Claims getClaims(String expiredToken) {
-		String token = expiredToken.replace("Bearer", "").trim();
+	private Claims getClaims(String inputToken) {
+		String token = inputToken.replace("Bearer", "").trim();
 		return parseClaims(token);
 	}
 

src/main/java/com/gamzabat/algohub/constants/ApiConstants.java

@@ -5,6 +5,10 @@ public final class ApiConstants {
 	public static final String BOJ_USER_PROFILE_URL = "https://www.acmicpc.net/user/";
 	public static final String BOJ_PROBLEM_URL = "www.acmicpc.net";
 
+	public static final String GITHUB_ACCESS_TOKEN_URL = "https://github.com/login/oauth/access_token";
+	public static final String GITHUB_USER_URL = "https://api.github.com/user";
+	public static final String GITHUB_EMAIL_URL = "https://api.github.com/user/emails";
+
 	private ApiConstants() {
 		throw new RuntimeException("Can not instantiate : ApiConstants");
 	}

src/main/java/com/gamzabat/algohub/exception/CustomExceptionHandler.java

@@ -5,6 +5,7 @@
 import org.springframework.web.bind.annotation.ControllerAdvice;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 
+import com.gamzabat.algohub.auth.exception.GithubApiException;
 import com.gamzabat.algohub.common.jwt.exception.ExpiredTokenException;
 import com.gamzabat.algohub.common.jwt.exception.TokenException;
 import com.gamzabat.algohub.feature.comment.exception.CommentValidationException;
@@ -183,4 +184,10 @@ protected ResponseEntity<ErrorResponse> handler(CheckPasswordFormException e) {
 		return ResponseEntity.status(e.getCode())
 			.body(new ErrorResponse(e.getCode(), e.getErrors(), null));
 	}
+
+	@ExceptionHandler(GithubApiException.class)
+	protected ResponseEntity<ErrorResponse> handler(GithubApiException e) {
+		return ResponseEntity.internalServerError()
+			.body(new ErrorResponse(HttpStatus.SERVICE_UNAVAILABLE.value(), e.getMessage(), null));
+	}
 }

src/main/java/com/gamzabat/algohub/feature/user/domain/User.java

@@ -41,6 +41,7 @@ public class User {
 	private String description = "";
 
 	private LocalDateTime deletedAt;
+	private String githubName;
 
 	@Enumerated(EnumType.STRING)
 	private Role role;
@@ -54,6 +55,7 @@ public User(String email, String password, String nickname, String bjNickname, S
 		this.profileImage = profileImage;
 		this.role = role;
 		this.deletedAt = null;
+		this.githubName = null;
 	}
 
 	public void editDescription(String description) {
@@ -75,4 +77,8 @@ public void editProfileImage(String profileImage) {
 	public void editPassword(String password) {
 		this.password = password;
 	}
+
+	public void editGithubName(String githubName) {
+		this.githubName = githubName;
+	}
 }

src/main/resources/application.yml

@@ -3,6 +3,7 @@ spring:
     import:
       - "jwt.yml"
       - "webhook.yml"
+      - "github.yml"
   profiles:
     active: dev
     group: