Deploy with Docker
Deploying ZenML in a Docker container.
The ZenML server container image is available at zenmldocker/zenml-server
and can be used to deploy ZenML with a container management or orchestration tool like docker and docker-compose, or a serverless platform like Cloud Run, Container Apps, and more! This guide walks you through the various configuration options that the ZenML server container expects as well as a few deployment use cases.
Try it out locally first
If you're just looking for a quick way to deploy the ZenML server using a container, without going through the hassle of interacting with a container management tool like docker and manually configuring your container, you can use the ZenML CLI to do so. You only need to have Docker installed and running on your machine:
This command deploys a ZenML server locally in a Docker container, then connects your client to it. Similar to running plain zenml up
, the server and the local ZenML client share the same SQLite database.
The rest of this guide is addressed to advanced users who are looking to manually deploy and manage a containerized ZenML server.
ZenML server configuration options
If you're planning on deploying a custom containerized ZenML server yourself, you probably need to configure some settings for it like the database it should use, the default user details, and more. The ZenML server container image uses sensible defaults, so you can simply start a container without worrying too much about the configuration. However, if you're looking to connect the ZenML server to an external MySQL database or secrets management service, to persist the internal SQLite database, or simply want to control other settings like the default account, you can do so by customizing the container's environment variables.
The following environment variables can be passed to the container:
ZENML_DEFAULT_PROJECT_NAME: The name of the default project created by the server on the first deployment, during database initialization. Defaults to
default
.ZENML_DEFAULT_USER_NAME: The name of the default admin user account created by the server on the first deployment, during database initialization. Defaults to
default
.ZENML_DEFAULT_USER_PASSWORD: The password to use for the default admin user account. Defaults to an empty password value, if not set.
ZENML_STORE_URL: This URL should point to an SQLite database file mounted in the container, or to a MySQL-compatible database service reachable from the container. It takes one of these forms:
or:
ZENML_STORE_SSL_CA: This can be set to a custom server CA certificate in use by the MySQL database service. Only valid when
ZENML_STORE_URL
points to a MySQL database that uses SSL-secured connections. The variable can be set either to the path where the certificate file is mounted inside the container or to the certificate contents themselves.ZENML_STORE_SSL_CERT: This can be set to a client SSL certificate required to connect to the MySQL database service. Only valid when
ZENML_STORE_URL
points to a MySQL database that uses SSL-secured connections and requires client SSL certificates. The variable can be set either to the path where the certificate file is mounted inside the container or to the certificate contents themselves. This variable also requiresZENML_STORE_SSL_KEY
to be set.ZENML_STORE_SSL_KEY: This can be set to a client SSL private key required to connect to the MySQL database service. Only valid when
ZENML_STORE_URL
points to a MySQL database that uses SSL-secured connections and requires client SSL certificates. The variable can be set either to the path where the certificate file is mounted inside the container or to the certificate contents themselves. This variable also requiresZENML_STORE_SSL_CERT
to be set.ZENML_STORE_SSL_VERIFY_SERVER_CERT: This boolean variable controls whether the SSL certificate in use by the MySQL server is verified. Only valid when
ZENML_STORE_URL
points to a MySQL database that uses SSL-secured connections. Defaults toFalse
.ZENML_LOGGING_VERBOSITY: Use this variable to control the verbosity of logs inside the container. It can be set to one of the following values:
NOTSET
,ERROR
,WARN
,INFO
(default),DEBUG
orCRITICAL
.ZENML_STORE_BACKUP_STRATEGY: This variable controls the database backup strategy used by the ZenML server. See the Database backup and recovery section for more details about this feature and other related environment variables. Defaults to
in-memory
.
If none of the ZENML_STORE_*
variables are set, the container will default to creating and using an SQLite database file stored at /zenml/.zenconfig/local_stores/default_zen_store/zenml.db
inside the container. The /zenml/.zenconfig/local_stores
base path where the default SQLite database is located can optionally be overridden by setting the ZENML_LOCAL_STORES_PATH
environment variable to point to a different path (e.g. a persistent volume or directory that is mounted from the host).
Secret store environment variables
Unless explicitly disabled or configured otherwise, the ZenML server will use the SQL database as a secrets store backend where secret values are stored. If you want to use an external secrets management service like the AWS Secrets Manager, GCP Secrets Manager, Azure Key Vault, HashiCorp Vault or even your custom Secrets Store back-end implementation instead, you need to configure it explicitly using docker environment variables. Depending on where you deploy your ZenML server and how your Kubernetes cluster is configured, you will also need to provide the credentials needed to access the secrets management service API.
Important: If you are updating the configuration of your ZenML Server container to use a different secrets store back-end or location, you should follow the documented secrets migration strategy to minimize downtime and to ensure that existing secrets are also properly migrated.
The SQL database is used as the default secret store location. You only need to configure these options if you want to change the default behavior.
It is particularly recommended to enable encryption at rest for the SQL database if you plan on using it as a secrets store backend. You'll have to configure the secret key used to encrypt the secret values. If not set, encryption will not be used and passwords will be stored unencrypted in the database.
ZENML_SECRETS_STORE_TYPE: Set this to
sql
in order to explicitly set this type of secret store.ZENML_SECRETS_STORE_ENCRYPTION_KEY: the secret key used to encrypt all secrets stored in the SQL secrets store. It is recommended to set this to a random string with a length of at least 32 characters, e.g.:
or:
Important: If you configure encryption for your SQL database secrets store, you should keep the
ZENML_SECRETS_STORE_ENCRYPTION_KEY
value somewhere safe and secure, as it will always be required by the ZenML server to decrypt the secrets in the database. If you lose the encryption key, you will not be able to decrypt the secrets in the database and will have to reset them.
ZENML_SECRETS_STORE_TYPE: Set this variable to none
to disable the secrets store functionality altogether.
Backup secrets store
A backup secrets store back-end may be configured for high-availability and backup purposes. or as an intermediate step in the process of migrating secrets to a different external location or secrets manager provider.
To configure a backup secrets store in the docker container, use the same approach and instructions documented for the primary secrets store, but set the **ZENML\_BACKUP\_SECRETS\_STORE\***
environment variables instead of **ZENML\_SECRETS\_STORE\***
, e.g.:
Advanced server configuration options
These configuration options are not required for most use cases, but can be useful in certain scenarios that require mirroring the same ZenML server configuration across multiple container instances (e.g. a Kubernetes deployment with multiple replicas):
ZENML_SERVER_JWT_SECRET_KEY: This is a secret key used to sign JWT tokens used for authentication. If not explicitly set, a random key is generated automatically by the server on startup and stored in the server's global configuration. This should be set to a random string with a recommended length of at least 32 characters, e.g.:
or:
Run the ZenML server with Docker
As previously mentioned, the ZenML server container image uses sensible defaults for most configuration options. This means that you can simply run the container with Docker without any additional configuration and it will work out of the box for most use cases:
Note: It is recommended to use a ZenML container image version that matches the version of your client, to avoid any potential API incompatibilities (e.g.
zenmldocker/zenml-server:0.21.1
instead ofzenmldocker/zenml-server
).
The above command will start a containerized ZenML server running on your machine that uses a temporary SQLite database file stored in the container. Temporary means that the database and all its contents (stacks, pipelines, pipeline runs, etc.) will be lost when the container is removed with docker rm
.
You can visit the ZenML dashboard at http://localhost:8080
and login with the default
username and empty password or connect your client to the server with the web login flow:
The localhost
URL will work, even if you are using Docker-backed ZenML orchestrators in your stack, like the local Docker orchestrator or a locally deployed Kubeflow orchestrator.
ZenML makes use of specialized DNS entries such as host.docker.internal
and host.k3d.internal
to make the ZenML server accessible from the pipeline steps running inside other Docker containers on the same machine.
You can manage the container with the usual Docker commands:
docker logs zenml
to view the server logsdocker stop zenml
to stop the serverdocker start zenml
to start the server againdocker rm zenml
to remove the container
If you are looking for a customized ZenML server Docker deployment, you can configure one or more of the supported environment variables and then pass them to the container using the docker run
--env
or --env-file
arguments (see the Docker documentation for more details). For example:
If you're looking for a quick way to run both the ZenML server and a MySQL database with Docker, you can deploy the ZenML server with Docker Compose.
The rest of this guide covers various advanced use cases for running the ZenML server with Docker.
Persisting the SQLite database
Depending on your use case, you may also want to mount a persistent volume or directory from the host into the container to store the ZenML SQLite database file. This can be done using the --mount
flag (see the Docker documentation for more details). For example:
This deployment has the advantage that the SQLite database file is persisted even when the container is removed with docker rm
.
Docker MySQL database
As a recommended alternative to the SQLite database, you can run a MySQL database service as another Docker container and connect the ZenML server container to it.
A command like the following can be run to start the containerized MySQL database service:
If you also wish to persist the MySQL database data, you can mount a persistent volume or directory from the host into the container using the --mount
flag, e.g.:
Configuring the ZenML server container to connect to the MySQL database is just a matter of setting the ZENML_STORE_URL
environment variable. We use the special host.docker.internal
DNS name that is resolved from within the Docker containers to the gateway IP address used by the Docker network (see the Docker documentation for more details). On Linux, this needs to be explicitly enabled in the docker run
command with the --add-host
argument:
Connecting your client to the ZenML server is the same as before:
Direct MySQL database connection
This scenario is similar to the previous one, but instead of running a ZenML server, the client is configured to connect directly to a MySQL database running in a Docker container.
As previously covered, the containerized MySQL database service can be started with a command like the following:
The ZenML client on the host machine can then be configured to connect directly to the database with a slightly different zenml connect
command:
Note The
localhost
hostname will not work with MySQL databases. You need to use the127.0.0.1
IP address instead.
ZenML server with docker-compose
docker-compose
Docker compose offers a simpler way of managing multi-container setups on your local machine, which is the case for instance if you are looking to deploy the ZenML server container and connect it to a MySQL database service also running in a Docker container.
To use Docker Compose, you need to install the docker-compose plugin on your machine first.
A docker-compose.yml
file like the one below can be used to start and manage the ZenML server container and the MySQL database service all at once:
Note the following:
ZENML_STORE_URL
is set to the special Dockerhost.docker.internal
hostname to instruct the server to connect to the database over the Docker network.The
extra_hosts
section is needed on Linux to make thehost.docker.internal
hostname resolvable from the ZenML server container.This example also uses the
ZENML_DEFAULT_USER_NAME
andZENML_DEFAULT_USER_PASSWORD
environment variables to customize the default account credentials.
To start the containers, run the following command from the directory where the docker-compose.yml
file is located:
or, if you need to use a different filename or path:
Connecting your client to the ZenML server is the same as before:
Tearing down the installation is as simple as running:
Database backup and recovery
An automated database backup and recovery feature is enabled by default for all Docker deployments. The ZenML server will automatically back up the database in-memory before every database schema migration and restore it if the migration fails.
The database backup automatically created by the ZenML server is only temporary and only used as an immediate recovery in case of database migration failures. It is not meant to be used as a long-term backup solution. If you need to back up your database for long-term storage, you should use a dedicated backup solution.
Several database backup strategies are supported, depending on where and how the backup is stored. The strategy can be configured by means of the ZENML_STORE_BACKUP_STRATEGY
environment variable:
disabled
- no backup is performedin-memory
- the database schema and data are stored in memory. This is the fastest backup strategy, but the backup is not persisted across container restarts, so no manual intervention is possible in case the automatic DB recovery fails after a failed DB migration. Adequate memory resources should be allocated to the ZenML server container when using this backup strategy with larger databases. This is the default backup strategy.database
- the database is copied to a backup database in the same database server. This requires theZENML_STORE_BACKUP_DATABASE
environment variable to be set to the name of the backup database. This backup strategy is only supported for MySQL compatible databases and the user specified in the database URL must have permissions to manage (create, drop, and modify) the backup database in addition to the main database.dump-file
- the database schema and data are dumped to a filesystem location inside the ZenML server container. This location can be customized by means of theZENML_STORE_BACKUP_DIRECTORY
environment variable. When this strategy is configured, users should mount a host directory in the container and point theZENML_STORE_BACKUP_DIRECTORY
variable to where it's mounted inside the container. If a host directory is not mounted, the dump file will be stored in the container's filesystem and will be lost when the container is removed.
The following additional rules are applied concerning the creation and lifetime of the backup:
a backup is not attempted if the database doesn't need to undergo a migration (e.g. when the ZenML server is upgraded to a new version that doesn't require a database schema change or if the ZenML version doesn't change at all).
a backup file or database is created before every database migration attempt (i.e. when the container starts). If a backup already exists (i.e. persisted in a mounted host directory or backup database), it is overwritten.
the persistent backup file or database is cleaned up after the migration is completed successfully or if the database doesn't need to undergo a migration. This includes backups created by previous failed migration attempts.
the persistent backup file or database is NOT cleaned up after a failed migration. This allows the user to manually inspect and/or apply the backup if the automatic recovery fails.
The following example shows how to deploy the ZenML server to use a mounted host directory to persist the database backup file during a database migration:
Troubleshooting
You can check the logs of the container to verify if the server is up and, depending on where you have deployed it, you can also access the dashboard at a localhost
port (if running locally) or through some other service that exposes your container to the internet.
CLI Docker deployments
If you used the zenml up --docker
CLI command to deploy the Docker ZenML server, you can check the logs with the command:
Manual Docker deployments
If you used the docker run
command to manually deploy the Docker ZenML server, you can check the logs with the command:
If you used the docker compose
command to manually deploy the Docker ZenML server, you can check the logs with the command:
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