com.exasol.versionnumberprovider.dockerhub.DockerhubClient Maven / Gradle / Ivy
package com.exasol.versionnumberprovider.dockerhub;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Logger;
/**
* This class uses the Docker Hub API to retrieve all tags for the Exasol docker-db image.
*
* Note that we don't use request {@code GET /v2//tags/list} as specified in the
* API documentation because this requires
* authentication. The request we use here does not require authentication but also does not support specifying a custom
* page size. That's why we always get 10 results per page and need to do multiple requests to retrieve all tags.
*/
public class DockerhubClient {
private static final Logger LOGGER = Logger.getLogger(DockerhubClient.class.getName());
private static final String INITIAL_URL = "https://registry.hub.docker.com/v2/repositories/exasol/docker-db/tags";
private final Deserializer deserializer;
private final SimpleHttpClient httpClient;
/**
* Create a new client for the Docker Hub API.
*/
public DockerhubClient() {
deserializer = new Deserializer();
httpClient = new SimpleHttpClient();
}
/**
* Retrieve all tags of the Exasol docker-db image.
*
* @return all tags.
*/
public List getAllTags() {
final List tags = new ArrayList<>();
String nextUrl = INITIAL_URL;
do {
final TagListPage tagList = getTagList(nextUrl);
tags.addAll(tagList.getTags());
nextUrl = tagList.getNextUrl();
} while (nextUrl != null);
return tags;
}
private TagListPage getTagList(final String url) {
LOGGER.finest(() -> "Fetching tag list " + url);
final String response = httpClient.getUrl(URI.create(url));
return deserializer.deserialize(response);
}
}