`pull-deps` is an Apache Druid tool that can pull down dependencies to the local repository and lay dependencies out into the extension directory as needed.
Don't pull down the default hadoop coordinate, i.e., org.apache.hadoop:hadoop-client:2.3.0. If `-h` option is supplied, then default hadoop coordinate will not be downloaded.
Add a remote repository. Unless `--no-default-remote-repositories` is provided, these will be used after https://repo1.maven.org/maven2/ and http://metamx.artifactoryonline.com/metamx/pub-libs-releases-local
Version to use for extension coordinate that doesn't have a version information. For example, if extension coordinate is `org.apache.druid.extensions:mysql-metadata-storage`, and default version is `{{DRUIDVERSION}}`, then this coordinate will be treated as `org.apache.druid.extensions:mysql-metadata-storage:{{DRUIDVERSION}}`
Use http/https proxy to send request to the remote repository servers. `--proxy-host` and `--proxy-port` must be set explicitly if this option is enabled.
1) Specify `druid.extensions.directory` and `druid.extensions.hadoopDependenciesDir`, these two properties tell `pull-deps` where to put extensions. If you don't specify them, default values will be used, see [Configuration](../configuration/index.md).
Suppose you want to download ```mysql-metadata-storage``` and ```hadoop-client```(both 2.3.0 and 2.4.0) with a specific version, you can run `pull-deps` command with `-c org.apache.druid.extensions:mysql-metadata-storage:{{DRUIDVERSION}}`, `-h org.apache.hadoop:hadoop-client:2.3.0` and `-h org.apache.hadoop:hadoop-client:2.4.0`, an example command would be:
Because `--clean` is supplied, this command will first remove the directories specified at `druid.extensions.directory` and `druid.extensions.hadoopDependenciesDir`, then recreate them and start downloading the extensions there. After finishing downloading, if you go to the extension directories you specified, you will see
Note that if you specify `--defaultVersion`, you don't have to put version information in the coordinate. For example, if you want `mysql-metadata-storage` to use version `{{DRUIDVERSION}}`, you can change the command above to
> Please note to use the pull-deps tool you must know the Maven groupId, artifactId, and version of your extension.
>
> For Druid community extensions listed [here](../development/extensions.md), the groupId is "org.apache.druid.extensions.contrib" and the artifactId is the name of the extension.