# Additional environment variables In addition to those environment variables associated with configurable options, the following environment variables can also be used to influence functionality: ```text GP_DEFAULT_KERNEL_SERVICE_ACCOUNT_NAME=default Kubernetes Provisioners only. This value indicates the default service account name to use for kernel namespaces when the KubernetesProvisioner needs to create the kernel's namespace and KERNEL_SERVICE_ACCOUNT_NAME has not been provided. GP_DOCKER_NETWORK=bridge Docker and Docker Swarm Provisioners only. Used by the docker deployment and launch scripts, this indicates the name of the docker network to use. The docker kernel launcher (launch_docker.py) defaults this value to 'bridge' only in cases where it wasn't previously set by the deployment script. GP_ENABLE_TUNNELING=False Indicates whether tunneling (via ssh) of the kernel and communication ports is enabled (True) or not (False). GP_KERNEL_CLUSTER_ROLE=kernel-controller or cluster-admin Kubernetes Provisioners only. The role to use when binding with the kernel service account. The rp-clusterrole.yaml file creates the cluster role 'kernel-controller' and conveys that name via GP_KERNEL_CLUSTER_ROLE. Should the deployment script not set this value, the KubernetesProvisioner will then use 'cluster-admin'. It is recommended this value be set to something other than 'cluster-admin'. GP_KERNEL_LAUNCH_TIMEOUT=30 The time (in seconds) hosting application will wait for a remote kernel's startup completion status before deeming the startup a failure. GP_KERNEL_LOG_DIR=/tmp The directory used during remote kernel launches of DistributedProvisioner kernels. Files in this directory will be of the form kernel-.log. GP_MAX_PORT_RANGE_RETRIES=5 The number of attempts made to locate an available port within the specified port range. Only applies when c.GatewayProvisionerConfigMixin.port_range (or GP_PORT_RANGE) has been specified or is in use for the given kernel. GP_MIN_PORT_RANGE_SIZE=1000 The minimum port range size permitted when c.GatewayProvisionerConfigMixin.port_range (or GP_PORT_RANGE) is specified or is in use for the given kernel. Port ranges reflecting smaller sizes will result in a failure to launch the corresponding kernel (since port-range can be specified within individual kernel specifications). GP_MIRROR_WORKING_DIRS=False Container-based Provisioners only. If True, kernel creation requests that specify KERNEL_WORKING_DIR will set the kernel container's working directory to that value. See also KERNEL_WORKING_DIR. GP_NAMESPACE=default Kubernetes Provisioners only. Used during Kubernetes deployment, this indicates the name of the namespace in which the hosting service is deployed. The namespace is created prior to deployment, and is set into the GP_NAMESPACE env via deployment.yaml script. This value is then used within the KubernetesProvisioner to coordinate kernel configurations. Should this value not be set during deployment, the KubernetesProvisioner will default its value to namespace 'default'. GP_PROHIBITED_GIDS=0 Container-based Provisioners only. A comma-separated list of group ids (GID) whose values are not allowed to be referenced by KERNEL_GID. This defaults to the root group id (0). Attempts to launch a kernel where KERNEL_GID's value is in this list will result in an exception indicating error 403 (Forbidden). See also GP_PROHIBITED_UIDS. GP_PROHIBITED_LOCAL_IPS='' A comma-separated list of local IPv4 addresses (or regular expressions) that should not be used when determining the response address used to convey connection information back to the host server from a remote kernel. In some cases, other network interfaces (e.g., docker with 172.17.0.*) can interfere - leading to connection failures during kernel startup. Example: GP_PROHIBITED_LOCAL_IPS=172.17.0.*,192.168.0.27 will eliminate the use of all addresses in 172.17.0 as well as 192.168.0.27 GP_PROHIBITED_UIDS=0 Container-based Provisioners only. A comma-separated list of user ids (UID) whose values are not allowed to be referenced by KERNEL_UID. This defaults to the root user id (0). Attempts to launch a kernel where KERNEL_UID's value is in this list will result in an exception indicating error 403 (Forbidden). See also GP_PROHIBITED_GIDS. GP_RESPONSE_IP=None The IP address to use to formulate the response address (with `GP_RESPONSE_PORT`). By default, the server's IP is used. However, we may find it necessary to use a different IP in cases where the target kernels are external to the host server (for example). It's value may also need to be set in cases where the computed (default) is not correct for the current topology. GP_RESPONSE_PORT=8877 The single response port used to receive connection information from launched kernels. GP_RESPONSE_PORT_RETRIES=10 The number of retries to attempt when the original response port (GP_RESPONSE_PORT) is found to be in-use. This value should be set to 0 (zero) if no port retries are desired. GP_SHARED_NAMESPACE=True Kubernetes Provisioners only. This value indicates whether (True) or not (False) all kernel pods should reside in the same namespace as the hosting server. If the server is intended to support multiple users, it is recommended that this value be set to False for better isolation of kernel resources. GP_SSH_PORT=22 Distributed Provisioners only. The port number used for ssh operations for installations choosing to configure the ssh server on a port other than the default 22. GP_REMOTE_PWD=None Distributed Provisioners only. The password to use to ssh to remote hosts. GP_REMOTE_USER=None Distributed Provisioners only. The username to use when connecting to remote hosts (default to `getpass.getuser()` when not set). GP_REMOTE_GSS_SSH=False Distributed Provisioners only. Use gss instead of GP_REMOTE_USER and GP_REMOTE_PWD to connect to remote host via SSH. Case insensitive. 'True' to enable, 'False', '' or unset to disable. Any other value will error. GP_YARN_CERT_BUNDLE= Yarn Provisioners only. The path to a .pem or any other custom truststore used as a CA bundle in yarn-api-client. ```