Merge branch...

# Service Specification Export

```markdown

# ServiceSpecificationFetcher

## Overview

The `ServiceSpecificationFetcher` is a Java-based application designed to fetch hierarchical data from RESTful APIs. It starts with a given `ServiceSpecification` UUID and recursively retrieves related `ServiceSpecification` and `ResourceSpecification` objects, saving each as JSON files in a structured directory hierarchy. Attachments and LCM rule specifications are also fetched and saved, ensuring all related data is organized and stored appropriately.

## Getting started

## Prerequisites

To make it easy for you to get started with GitLab, here's a list of recommended next steps.

- Java 17+

- Maven

- Docker (optional, for containerized deployment)

Already a pro? Just edit this README.md and make it your own. Want to make it easy? [Use the template at the bottom](#editing-this-readme)!

## Configuration

## Add your files

The application requires a configuration file named `config.properties` with the following properties:

- [ ] [Create](https://docs.gitlab.com/ee/user/project/repository/web_editor.html#create-a-file) or [upload](https://docs.gitlab.com/ee/user/project/repository/web_editor.html#upload-a-file) files

- [ ] [Add files using the command line](https://docs.gitlab.com/ee/gitlab-basics/add-file.html#add-a-file-using-the-command-line) or push an existing Git repository with the following command:

```

cd existing_repo

git remote add origin https://labs.etsi.org/rep/osl/utilities/service-specification-export.git

git branch -M main

git push -uf origin main

```ini

keycloak.url=http://keycloak:8080/auth/realms/openslice/protocol/openid-connect/token

client.id=osapiWebClientId

client.secret=admin

username=admin

password=admin

sourceApiEndpoint.url=http://localhost/tmf-api

serviceSpecification.uuid=487b9377-460d-4498-a8f3-a23cd7595b06

```

## Integrate with your tools

- [ ] [Set up project integrations](https://labs.etsi.org/rep/osl/utilities/service-specification-export/-/settings/integrations)

## Collaborate with your team

## Building the Project

- [ ] [Invite team members and collaborators](https://docs.gitlab.com/ee/user/project/members/)

- [ ] [Create a new merge request](https://docs.gitlab.com/ee/user/project/merge_requests/creating_merge_requests.html)

- [ ] [Automatically close issues from merge requests](https://docs.gitlab.com/ee/user/project/issues/managing_issues.html#closing-issues-automatically)

- [ ] [Enable merge request approvals](https://docs.gitlab.com/ee/user/project/merge_requests/approvals/)

- [ ] [Automatically merge when pipeline succeeds](https://docs.gitlab.com/ee/user/project/merge_requests/merge_when_pipeline_succeeds.html)

To build the project, use Maven:

## Test and Deploy

Use the built-in continuous integration in GitLab.

- [ ] [Get started with GitLab CI/CD](https://docs.gitlab.com/ee/ci/quick_start/index.html)

- [ ] [Analyze your code for known vulnerabilities with Static Application Security Testing(SAST)](https://docs.gitlab.com/ee/user/application_security/sast/)

- [ ] [Deploy to Kubernetes, Amazon EC2, or Amazon ECS using Auto Deploy](https://docs.gitlab.com/ee/topics/autodevops/requirements.html)

- [ ] [Use pull-based deployments for improved Kubernetes management](https://docs.gitlab.com/ee/user/clusters/agent/)

- [ ] [Set up protected environments](https://docs.gitlab.com/ee/ci/environments/protected_environments.html)

```sh

mvn clean install

```

***

## Running the Project

# Editing this README

To run the project, execute the following command:

When you're ready to make this README your own, just edit this file and use the handy template below (or feel free to structure it however you want - this is just a starting point!). Thank you to [makeareadme.com](https://www.makeareadme.com/) for this template.

```sh

java -cp target/servicespecificationfetcher.jar org.osl.etsi.util.ServiceSpecificationFetcher

```

## Suggestions for a good README

Every project is different, so consider which of these sections apply to yours. The sections used in the template are suggestions for most open source projects. Also keep in mind that while a README can be too long and detailed, too long is better than too short. If you think your README is too long, consider utilizing another form of documentation rather than cutting out information.

## Docker Deployment

## Name

Choose a self-explaining name for your project.

### Building the Docker Image

## Description

Let people know what your project can do specifically. Provide context and add a link to any reference visitors might be unfamiliar with. A list of Features or a Background subsection can also be added here. If there are alternatives to your project, this is a good place to list differentiating factors.

To build the Docker image, use the following command:

## Badges

On some READMEs, you may see small images that convey metadata, such as whether or not all the tests are passing for the project. You can use Shields to add some to your README. Many services also have instructions for adding a badge.

```sh

docker build -t servicespecificationfetcher .

```

## Visuals

Depending on what you are making, it can be a good idea to include screenshots or even a video (you'll frequently see GIFs rather than actual videos). Tools like ttygif can help, but check out Asciinema for a more sophisticated method.

### Running the Docker Container

## Installation

Within a particular ecosystem, there may be a common way of installing things, such as using Yarn, NuGet, or Homebrew. However, consider the possibility that whoever is reading your README is a novice and would like more guidance. Listing specific steps helps remove ambiguity and gets people to using your project as quickly as possible. If it only runs in a specific context like a particular programming language version or operating system or has dependencies that have to be installed manually, also add a Requirements subsection.

To run the Docker container, use the following command, ensuring to mount the configuration file and data folder:

## Usage

Use examples liberally, and show the expected output if you can. It's helpful to have inline the smallest example of usage that you can demonstrate, while providing links to more sophisticated examples if they are too long to reasonably include in the README.

```sh

docker run -v /local/path/to/config.properties:/app/config.properties -v /local/path/to/your-data-folder:/app/data-folder servicespecificationfetcher uuid

## Support

Tell people where they can go to for help. It can be any combination of an issue tracker, a chat room, an email address, etc.

docker run -v C:\openslice\servicespecificationfetcher\src\main\resources\config.properties:/app/config.properties -v C:\openslice\servicespecificationfetcher:/app/data-folder servicespecificationfetcher f51cb185-6663-49e8-b195-83deeae32eed

```

## Roadmap

If you have ideas for releases in the future, it is a good idea to list them in the README.

## File Hierarchy Structure

## Contributing

State if you are open to contributions and what your requirements are for accepting them.

The fetched data is saved in a structured directory hierarchy as follows:

For people who want to make changes to your project, it's helpful to have some documentation on how to get started. Perhaps there is a script that they should run or some environment variables that they need to set. Make these steps explicit. These instructions could also be useful to your future self.

```

root_directory/

├── serviceSpecificationId1/

│   ├── serviceSpecificationId1.json

│   ├── serviceSpecificationLcmRules/

│   │   ├── ruleId1.json

│   │   ├── ruleId2.json

│   │   └── ...

│   ├── serviceSpecificationServiceRelationships/

│   │   ├── relatedServiceSpecificationId1/

│   │   │   ├── relatedServiceSpecificationId1.json

│   │   │   ├── ...

│   │   └── ...

│   ├── serviceSpecificationResourceRelationships/

│   │   ├── relatedResourceSpecificationId1/

│   │   │   ├── relatedResourceSpecificationId1.json

│   │   │   ├── ...

│   │   └── ...

│   ├── attachments/

│   │   ├── attachment1.ext

│   │   ├── attachment2.ext

│   │   └── ...

│   └── ...

├── serviceSpecificationId2/

│   ├── serviceSpecificationId2.json

│   ├── ...

└── ...

```

You can also document commands to lint the code or run tests. These steps help to ensure high code quality and reduce the likelihood that the changes inadvertently break something. Having instructions for running tests is especially helpful if it requires external setup, such as starting a Selenium server for testing in a browser.

## Error Handling & Logging

## Authors and acknowledgment

Show your appreciation to those who have contributed to the project.

- **HTTP Errors**: An `IOException` is thrown for non-200 HTTP status codes.

- **JSON Parsing Errors**: Errors are caught and printed to the console.

- **Logging**: `System.out.println` is used for logging.

## License

For open source projects, say how it is licensed.

## Project status

If you have run out of energy or time for your project, put a note at the top of the README saying that development has slowed down or stopped completely. Someone may choose to fork your project or volunteer to step in as a maintainer or owner, allowing your project to keep going. You can also make an explicit request for maintainers.

This project is licensed under the Apache Version 2.0 License.

```

 No newline at end of file

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">

	<modelVersion>4.0.0</modelVersion>

	<groupId>org.etsi.osl.util</groupId>

	<artifactId>servicespecificationfetcher</artifactId>

	<version>0.0.1-SNAPSHOT</version>

    <!-- Specify the Java version you're using -->

    <properties>

        <maven.compiler.source>17</maven.compiler.source>

        <maven.compiler.target>17</maven.compiler.target>

    </properties>

    <dependencies>

        <!-- Jackson JSON Processor -->

        <dependency>

            <groupId>com.fasterxml.jackson.core</groupId>

            <artifactId>jackson-databind</artifactId>

            <version>2.12.3</version>

        </dependency>

        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->

        <dependency>

            <groupId>org.slf4j</groupId>

            <artifactId>slf4j-api</artifactId>

            <version>2.0.16</version>

        </dependency>

        <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic -->

        <dependency>

            <groupId>ch.qos.logback</groupId>

            <artifactId>logback-classic</artifactId>

            <version>1.5.8</version>

        </dependency>

        <!-- Google Gson -->

        <dependency>

            <groupId>com.google.code.gson</groupId>

            <artifactId>gson</artifactId>

            <version>2.8.6</version>

        </dependency>

        <!-- Your custom library dependency -->

	    <dependency>

	        <groupId>org.etsi.osl</groupId>

	        <artifactId>org.etsi.osl.model.tmf</artifactId>

	        <version>1.0.0</version>

	    </dependency>

    </dependencies>

    <build>

        <plugins>

            <!-- Maven Compiler Plugin -->

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-compiler-plugin</artifactId>

                <version>3.8.1</version>

                <configuration>

                    <source>17</source>

                    <target>17</target>

                </configuration>

            </plugin>

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-jar-plugin</artifactId>

                <version>3.2.0</version>

                <configuration>

                    <archive>

                        <manifest>

                            <mainClass>org.osl.etsi.util.ServiceSpecificationFetcher</mainClass>

                        </manifest>

                    </archive>

                </configuration>

            </plugin>

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-shade-plugin</artifactId>

                <version>3.4.1</version>

                <executions>

                    <execution>

                        <phase>package</phase>

                        <goals>

                            <goal>shade</goal>

                        </goals>

                        <configuration>

                            <createDependencyReducedPom>true</createDependencyReducedPom>

                            <transformers>

                                <!-- Ensures that the manifest specifies the main class -->

                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">

                                    <mainClass>org.osl.etsi.util.ServiceSpecificationFetcher</mainClass> <!-- Fully Qualified Name -->

                                </transformer>

                            </transformers>

                        </configuration>

                    </execution>

                </executions>

            </plugin>

        </plugins>

    </build>

</project>  

package org.osl.etsi.util;

import com.fasterxml.jackson.databind.JsonNode;

import com.fasterxml.jackson.databind.ObjectMapper;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import java.io.IOException;

import java.net.URI;

import java.net.URLEncoder;

import java.net.http.HttpClient;

import java.net.http.HttpRequest;

import java.net.http.HttpResponse;

import java.nio.charset.StandardCharsets;

import java.time.Instant;

import java.util.Properties;

public class KeycloakAuthenticator {

    private static final Logger logger = LoggerFactory.getLogger(KeycloakAuthenticator.class.getName());

    private final Properties config;

    private final HttpClient client;

    private final ObjectMapper objectMapper;

    private String currentToken;

    private long tokenExpiryTime;

    private long tokenRefreshBufferSeconds;

    /**

     * Constructs a KeycloakAuthenticator with the specified configuration file path.

     *

     * @param configFilePath The file path to the configuration properties file.

     * @throws IOException If there is an error loading the configuration file.

     */

    public KeycloakAuthenticator(Properties config) throws IOException {

        this.config = config;

        this.client = HttpClient.newHttpClient();

        this.objectMapper = new ObjectMapper();

        setTokenRefreshBufferSeconds();

    }

    /**

     * Loads the configuration properties from the specified file path.

     *

     * @param configFilePath The file path to the configuration properties file.

     * @return The token refresh buffer time in seconds.

     * @throws IOException If the configuration file cannot be read.

     */

    private void setTokenRefreshBufferSeconds() throws IOException {

        // Load the token refresh buffer time, defaulting to 60 seconds if not specified

        String bufferSecondsStr = this.config.getProperty("token.refresh.buffer.seconds", "60");

        long bufferSeconds;

        try {

            bufferSeconds = Long.parseLong(bufferSecondsStr);

            if (bufferSeconds < 0) {

                throw new NumberFormatException("Buffer seconds cannot be negative.");

            }

        } catch (NumberFormatException ex) {

            logger.warn("Invalid token.refresh.buffer.seconds value: " + bufferSecondsStr + ". Using default of 60 seconds.");

            bufferSeconds = 60;

        }

        logger.info("Token refresh buffer set to " + bufferSeconds + " seconds.");

        this.tokenRefreshBufferSeconds=bufferSeconds;

    }

    /**

     * Retrieves a valid access token. If the current token is expired or not present,

     * it authenticates with Keycloak to obtain a new one.

     *

     * @return A valid access token as a String.

     * @throws IOException          If an I/O error occurs during authentication.

     * @throws InterruptedException If the HTTP request is interrupted.

     */

    public synchronized String getToken() throws IOException, InterruptedException {

        long currentEpochSeconds = Instant.now().getEpochSecond();

        if (currentToken != null && currentEpochSeconds < (tokenExpiryTime - tokenRefreshBufferSeconds)) {

            logger.info("Using cached token. Token expires at " + Instant.ofEpochSecond(tokenExpiryTime));

            return currentToken;

        } else {

            logger.info("Cached token is missing or nearing expiration. Authenticating to obtain a new token.");

            return authenticateAndGetToken();

        }

    }

    /**

     * Authenticates with Keycloak and retrieves a new access token.

     *

     * @return The new access token as a String.

     * @throws IOException          If the authentication request fails.

     * @throws InterruptedException If the HTTP request is interrupted.

     */

    private String authenticateAndGetToken() throws IOException, InterruptedException {

        String keycloakUrl = config.getProperty("keycloak.url");

        String clientId = config.getProperty("client.id");

        String clientSecret = config.getProperty("client.secret");

        String username = config.getProperty("username");

        String password = config.getProperty("password");

        // Validate required properties

        if (keycloakUrl == null || clientId == null || username == null || password == null) {

            String errorMsg = "Missing required configuration properties.";

            logger.error(errorMsg);

            throw new IOException(errorMsg);

        }

        // Build the form data with URL encoding

        String form = buildFormData(clientId, clientSecret, username, password);

        HttpRequest request = HttpRequest.newBuilder()

                .uri(URI.create(keycloakUrl))

                .header("Content-Type", "application/x-www-form-urlencoded")

                .POST(HttpRequest.BodyPublishers.ofString(form))

                .build();

        logger.info("Sending authentication request to Keycloak.");

        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());

        if (response.statusCode() == 200) {

            JsonNode responseJson = objectMapper.readTree(response.body());

            currentToken = responseJson.get("access_token").asText();

            long expiresIn = responseJson.get("expires_in").asLong();

            tokenExpiryTime = Instant.now().getEpochSecond() + expiresIn;

            logger.info("Authentication successful. Token obtained. Token expires in " + expiresIn + " seconds.");

            return currentToken;

        } else {

            String errorMsg = "Authentication failed: HTTP status " + response.statusCode() + ": " + response.body();

            logger.error(errorMsg);

            throw new IOException(errorMsg);

        }

    }

    /**

     * Builds the URL-encoded form data for the authentication request.

     *

     * @param clientId     The client ID.

     * @param clientSecret The client secret (optional).

     * @param username     The username.

     * @param password     The password.

     * @return The URL-encoded form data as a String.

     * @throws IOException If URL encoding fails.

     */

    private String buildFormData(String clientId, String clientSecret, String username, String password) throws IOException {

        StringBuilder form = new StringBuilder();

        form.append("client_id=").append(urlEncode(clientId));

        if (clientSecret != null && !clientSecret.isEmpty()) {

            form.append("&client_secret=").append(urlEncode(clientSecret));

        }

        form.append("&username=").append(urlEncode(username));

        form.append("&password=").append(urlEncode(password));

        form.append("&grant_type=password");

        return form.toString();

    }

    /**

     * URL-encodes a string using UTF-8 encoding.

     *

     * @param value The string to encode.

     * @return The URL-encoded string.

     * @throws IOException If UTF-8 encoding is not supported.

     */

    private String urlEncode(String value) throws IOException {

        try {

            return URLEncoder.encode(value, StandardCharsets.UTF_8.toString());

        } catch (Exception ex) {

            logger.error("URL encoding failed for value: " + value, ex);

            throw new IOException("URL encoding failed.", ex);

        }

    }

}