Add service to install a plugin from a given url

CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [Unreleased]
 ### Added
 - Sonarcloud check
+- Possibility to install a plugin via the frontpage
 
 ### Changed
 - CoffeeNet Starter Parent to version `0.38.2`

src/main/java/coffee/synyx/frontpage/installer/PluginConfiguration.java

@@ -0,0 +1,17 @@
+package coffee.synyx.frontpage.installer;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author Tobias Schneider
+ */
+@Configuration
+public class PluginConfiguration {
+
+    @Bean
+    PluginConfigurationProperties pluginConfigurationProperties() {
+
+        return new PluginConfigurationProperties();
+    }
+}

src/main/java/coffee/synyx/frontpage/installer/PluginConfigurationProperties.java

@@ -0,0 +1,24 @@
+package coffee.synyx.frontpage.installer;
+
+import org.hibernate.validator.constraints.NotEmpty;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.validation.annotation.Validated;
+
+/**
+ * @author Tobias Schneider
+ */
+@Validated
+@ConfigurationProperties("frontpage.plugins")
+public class PluginConfigurationProperties {
+
+    @NotEmpty
+    private String directory = "./plugins";
+
+    public String getDirectory() {
+        return directory;
+    }
+
+    public void setDirectory(String directory) {
+        this.directory = directory;
+    }
+}

src/main/java/coffee/synyx/frontpage/installer/PluginInstallationException.java

@@ -0,0 +1,11 @@
+package coffee.synyx.frontpage.installer;
+
+/**
+ * @author Tobias Schneider
+ */
+public class PluginInstallationException extends RuntimeException {
+
+    PluginInstallationException(String message) {
+        super(message);
+    }
+}

src/main/java/coffee/synyx/frontpage/installer/PluginInstallerService.java

@@ -0,0 +1,16 @@
+package coffee.synyx.frontpage.installer;
+
+/**
+ * @author Tobias Schneider
+ */
+public interface PluginInstallerService {
+
+    /**
+     * Installs a plugin into the defined directory of `frontpage.plugins.directory`
+     *
+     * @param url of the plugin to download and install
+     *
+     * @throws PluginInstallationException if an error occurred
+     */
+    void installPlugin(String url);
+}

src/main/java/coffee/synyx/frontpage/installer/SimplePluginInstallerService.java

@@ -0,0 +1,82 @@
+package coffee.synyx.frontpage.installer;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestTemplate;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import static java.lang.String.format;
+import static java.lang.invoke.MethodHandles.lookup;
+import static org.springframework.http.HttpMethod.GET;
+import static org.springframework.http.HttpStatus.OK;
+
+/**
+ * @author Tobias Schneider
+ */
+@Service
+public class SimplePluginInstallerService implements PluginInstallerService {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(lookup().lookupClass());
+
+    private final RestTemplate restTemplate;
+    private final PluginConfigurationProperties pluginConfigurationProperties;
+
+    @Autowired
+    public SimplePluginInstallerService(RestTemplate restTemplate, PluginConfigurationProperties pluginConfigurationProperties) {
+
+        this.restTemplate = restTemplate;
+        this.pluginConfigurationProperties = pluginConfigurationProperties;
+    }
+
+    @Override
+    public void installPlugin(String url) {
+
+        HttpHeaders headers = new HttpHeaders();
+        HttpEntity<String> entity = new HttpEntity<>(headers);
+
+        ResponseEntity<byte[]> response = restTemplate.exchange(url, GET, entity, byte[].class);
+
+        if (response.getStatusCode() == OK) {
+
+            createPluginDirectory();
+
+            Path pluginUri = Paths.get(pluginConfigurationProperties.getDirectory(), getPluginName(url));
+            try {
+                Files.write(pluginUri, response.getBody());
+            } catch (IOException e) {
+                throw new PluginInstallationException(format("IO Error occurred while saving the plugin to %s", pluginUri));
+            }
+        }
+    }
+
+    private void createPluginDirectory() {
+
+        if (new File(pluginConfigurationProperties.getDirectory()).mkdirs()) {
+            LOGGER.debug("{} was created", pluginConfigurationProperties.getDirectory());
+        }
+    }
+
+    private String getPluginName(String url) {
+
+        String path;
+        try {
+            path = new URI(url).getPath();
+        } catch (URISyntaxException e) {
+            throw new PluginInstallationException("Url of plugin is in wrong format and violates RFC 2396");
+        }
+
+        return path.substring(path.lastIndexOf('/') + 1);
+    }
+}

src/test/java/coffee/synyx/frontpage/installer/SimplePluginInstallerServiceIT.java

@@ -0,0 +1,61 @@
+package coffee.synyx.frontpage.installer;
+
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.web.client.RestTemplate;
+
+import java.io.File;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+
+/**
+ * @author Tobias Schneider
+ */
+@RunWith(SpringRunner.class)
+public class SimplePluginInstallerServiceIT {
+
+    private PluginInstallerService sut;
+
+    @Before
+    public void setUp() {
+
+        final PluginConfigurationProperties pluginConfigurationProperties = new PluginConfigurationProperties();
+
+        sut = new SimplePluginInstallerService(new RestTemplate(), pluginConfigurationProperties);
+    }
+
+    @After
+    public void tearDown() {
+
+        deleteDirectory(new File("./plugins"));
+    }
+
+
+    @Test
+    public void downloadPlugin() {
+        String url = "https://github.com/coffeenet/coffeenet-frontpage-plugin-feed/releases/download/0.2.0/" +
+            "frontpage-plugin-feed-0.2.0-jar-with-dependencies.jar";
+
+        sut.installPlugin(url);
+
+        File plugin = new File("./plugins/frontpage-plugin-feed-0.2.0-jar-with-dependencies.jar");
+
+        assertThat(plugin.exists()).isTrue();
+        assertThat(plugin.isFile()).isTrue();
+    }
+
+    private boolean deleteDirectory(File directoryToBeDeleted) {
+        File[] allContents = directoryToBeDeleted.listFiles();
+        if (allContents != null) {
+            for (File file : allContents) {
+                deleteDirectory(file);
+            }
+        }
+        return directoryToBeDeleted.delete();
+    }
+}