Então para renovar os certificados, o programa de renovação precisa provar para a autoridade (Let's Encrypt) que ele realmente "possui" e controla esse domínio.

Para fazer isso, e acomodar as necessidades de diferentes aplicações, existem diferentes opções para esse programa. Algumas escolhas populares são:

* Modificar alguns registros DNS

     * defined as plugins).
     *
     * @param classLoadingStrategy a classLoadingStrategy object.
     */
    public void setClassLoadingStrategy(String classLoadingStrategy) {
        this.classLoadingStrategy = classLoadingStrategy;
    } // -- void setClassLoadingStrategy( String )

    /**
     * Set the group ID of the extension's artifact.
     *
     * @param groupId a groupId object.
     */

     * from the runtime environment like {@link System#getProperties()} and environment variables.
     *
     * @param systemProperties The system properties, may be {@code null}.
     * @return This request, never {@code null}.
     */
    MavenExecutionRequest setSystemProperties(Properties systemProperties);

    /**

    // Constructor
    ArtifactScopeEnum(int id) {
        this.id = id;
    }

    int getId() {
        return id;
    }

    /**
     * Helper method to simplify null processing
     *
     * @param scope a scope or {@code null}
     * @return the provided scope or DEFAULT_SCOPE
     */
    public static ArtifactScopeEnum checkScope(ArtifactScopeEnum scope) {
        return scope == null ? DEFAULT_SCOPE : scope;
    }

     *
     * @param scopes The scopes to enable, along with all implied scopes, may be {@code null}.
     */
    public CumulativeScopeArtifactFilter(Collection<String> scopes) {
        this.scopes = new HashSet<>();

        addScopes(scopes);
    }

    /**
     * Creates a new filter that combines the specified filters.
     *
     * @param filters The filters to combine, may be {@code null}.

     * collected from this method in combination with a custom cache implementation to dispose unused records from the
     * cache.
     *
     * @param project The project that employs the plugin realm, must not be {@code null}.
     * @param record The cache record being used for the project, must not be {@code null}.
     */
    void register(MavenProject project, Key cacheKey, CacheRecord record);

    // ------------------------------------------------------------------------
    /**
     * construct graph from a "dirty" tree
     *
     * @param tree "dirty" tree root
     * @param versionedVertices true if graph nodes should be versioned (different versions -> different nodes)
     * @param scopedVertices true if graph nodes should be versioned and scoped
     * (different versions and/or scopes -> different nodes)
     *
     */

        }
    }

    public interface ContentTransformer {
        /**
         * Interpolate the value read from the xpp3 document
         * @param source The source value
         * @param fieldName A description of the field being interpolated. The implementation may use this to
         *                           log stuff.
         * @return The interpolated value.
         */

     * in the model's plugin section need to be subjected to the model's plugin management.
     *
     * @param model The model into which to inject the default plugin executions for its packaging, must not be
     *            <code>null</code>.
     * @param request The model building request that holds further settings, must not be {@code null}.
     * @param problems The container used to collect problems that were encountered, must not be {@code null}.
     */

     * </ul>
     *
     * <p>The implementation must ensure that the returned object is functionally
     * equivalent to the input object from the perspective of the Maven model.</p>
     *
     * @param <T> the type of the model object
     * @param object the model object to process
     * @return the processed object (may be the same instance, a pooled instance, or a modified instance)