The Kubernetes platform.
The Package manager.
The Open Service Broker.
To run Drycc Workflow on a Kubernetes cluster, there are a few requirements to keep in mind.
Drycc Workflow requires Kubernetes v1.16.15 or later.
Workflow supports the use of ACME to manage automatic certificates, cert-manager is also one of the necessary components.
Workflow supports stateful apps. You can create and use them through the 'drycc volumes' command. If you want to use this feature, you must have a
StorageClass that supports
A variety of Drycc Workflow components rely on an object storage system to do their work, including storing application slugs, Docker images and database logs.
Drycc Workflow ships with Minio by default, which provides in-cluster, ephemeral object storage. This means that if the Minio server crashes, all data will be lost. Therefore, Minio should be used for development or testing only.
Workflow supports Amazon Simple Storage Service (S3), Google Cloud Storage (GCS), OpenShift Swift, and Azure Blob Storage. See configuring object storage for setup instructions.
When deploying Drycc Workflow, it's important to provision machines with adequate resources. Drycc is a highly-available distributed system, which means that Drycc components and your deployed applications will move around the cluster onto healthy hosts as hosts leave the cluster for various reasons (failures, reboots, autoscalers, etc.). Because of this, you should have ample spare resources on any machine in your cluster to withstand the additional load of running services for failed machines.
Drycc Workflow components use about 2.5GB of memory across the cluster, and require approximately 30GB of hard disk space. Because it may need to handle additional load if another one fails, each machine has minimum requirements of:
Note that these estimates are for Drycc Workflow and Kubernetes only. Be sure to leave enough spare capacity for your application footprint as well.
Running smaller machines will likely result in increased system load and has been known to result in component failures and instability.
Workflow versions prior to 2.2 require '--insecure-registry' to function properly. Depending on
your Kubernetes and Docker configuration, setting
EXTRA_DOCKER_OPTS="--insecure-registry=10.0.0.0/8" may be sufficient.
If you are using Docker with OverlayFS, you must disable SELinux by adding
EXTRA_DOCKER_OPTS. For more background information, see: