• Create a new Container locally.


ern create-container


--baseComposite <compositePath>

  • Git or File System path, to the custom Composite repository (refer to the custom Composite documentation for more information).

--descriptor/-d <descriptor>

  • Create a new container including all the MiniApps listed in the Cauldron for the given complete native application descriptor

  • Use this option if you want to locally generate a container that mirrors the container of a given native application version.


  • Create Container using the latest commits made to each of the MiniApp branches (HEAD), rather than using the MiniApps SHAs that are inside the current Container version.

  • This flag is only used when creating a Container from a Cauldron descriptor

  • This flag will be ignored if the target descriptor does not contain any MiniApps tracking git branches

    Default false

--miniapps/-m <miniapps>

  • Create a new custom container including all the given MiniApps

  • The MiniApps passed to this command can be a valid Yarn package format or a Git format or file scheme.

--dependencies/--deps <dependencies>

  • Inject the provided extra native dependencies in your locally generated container

  • This option can only be used when generating a container that is not based on a native application version from Cauldron (--descriptor option).

    For the latter, if you want to add extra native dependencies to your container that are not listed as dependencies of any of the MiniApps, you can instead use the ern cauldron add dependencies command to add the extra native dependencies directly in the native application version stored in Cauldron.

    You can only provide published dependencies to this command.

    You cannot use the Git or file package descriptors for referring to the dependencies.

--platform/-p <android|ios>

  • Specify the target platform for this container

  • If not explicitly provided, the command prompts you to choose between the iOS or the Android platform before execution.

--outDir/--out <directory>

  • Specify the directory to output the generated container to

  • The output directory should either not exist (it will be created) or be empty

  • Default If this option is not provided, the container is generated in the default platform directory ~/.ern/containergen/out.


  • Inform the Container generator to ignore any rnpm assets optionally declared by MiniApps. This can be used in case you want to keep specific rnpm assets inside the native application itself and not the Container.

  • This flag wil have no effect for a Container generated from a Cauldron as the Container configuration stored in the Cauldron will take precedence.

  • Default Do not ignore rnpm assets and package them inside the generated Container.


  • Optional extra configuration specific to creating container

  • Override the android build config during container generation by passing androidConfig attributes

    • As a json string

      For example --extra '{"androidConfig": {"androidGradlePlugin": "3.2.1","buildToolsVersion": "28.0.3","compileSdkVersion": "28","gradleDistributionVersion": "4.6","minSdkVersion": "19","supportLibraryVersion": "28.0.0","targetSdkVersion": "28"}}'

    • As a file path

      For example --extra /Users/username/my-container-config.json

      In that case, the configuration will be read from the file.

    • As a Cauldron file path

      For example --extra cauldron://config/container/my-container-config.json

      In that case, the configuration will be read from the file stored in Cauldron.

      For this way to work, the file must exist in Cauldron (you can add a file to the cauldron by using the [ern cauldron add file] command).


  • The ern create-container command can be used to create a container locally, for development, debugging and experimentation purposes.

  • Container generation and transformation/publication are separate processes (see Related commands section below for specific commands)

  • To create a container that is published so that your native application team can use the container, you should use one of the Cauldron commands to add your MiniApps to a specified native application version in the Cauldron, which will trigger the generation and publication of a Container. See Related commands.

ern transform-container | Transform a local Container. ern publish-container | Publish a local Container. ern create-composite | Creates a JS Composite project locally

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