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 to the default remote repository list, which includes https://repo1.maven.org/maven2/ and https://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 `io.druid.extensions:mysql-metadata-storage`, and default version is `0.9.0`, then this coordinate will be treated as `io.druid.extensions:mysql-metadata-storage:0.9.0`
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.html).
2) Tell `pull-deps` what to download using `-c` or `-h` option, which are followed by a maven coordinate.
Suppose you want to download ```druid-rabbitmq```, ```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 io.druid.extensions:druid-examples:0.9.0`, `-c io.druid.extensions:mysql-metadata-storage:0.9.0`, `-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 both `druid-rabbitmq` and `mysql-metadata-storage` to use version `0.9.0`, 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 <ahref="../development/extensions.html">here</a>, the groupId is "io.druid.extensions.contrib" and the artifactId is the name of the extension.