Overview of SupplyChain

This topic tells you about the SupplyChain primitive in Tanzu Supply Chain. The SupplyChain primitive unifies the Tanzu Supply Chain operation. For reference information, see SupplyChain.

Caution

Tanzu Supply Chain is currently in beta and is not intended for production use. It is intended only for evaluation purposes for the next generation Supply Chain. For the current Supply Chain solution, see the Supply Chain Choreographer documentation.

SupplyChain describes a process with stages

In physical manufacturing a supply chain is the process that delivers an end product to customers, starting with the raw materials. In software, a supply chain delivers an operational end product to customers, starting with source code. VMware refers to this as the golden path to production.

Tanzu Supply Chain provides a primitive called SupplyChain, which is a Kubernetes custom resource that you use to define all, or portions of, your software supply chain.

This section describes typical uses of the SupplyChain primitive for Tanzu Supply Chain.

SupplyChain describes a build process

A SupplyChain primitive can describe the process of converting source code into a runnable or deployable package.

Typical stages in this process are:

• Build:
  • Compile a binary from source.
  • Create an OCI image from the binary.
• Configure:
  • Create deployment artifacts, such as Kubernetes Pod definitions.
• Package:
  • Create packaging artifacts, such as a Carvel package or a Helm Chart.

SupplyChain defines a configuration resource

A SupplyChain primitive brings together the API for a user to apply to the cluster by:

• Defining a group and kind for a resource called a Workload. For reference information, see spec.defines.
• Specifying components used in the stages of the SupplyChain. For reference information, see spec.stages[].

By selecting components, SupplyChain aggregates each configuration for each component as a single API specification for the Workload.

Note

Workload might be renamed in a later Tanzu Application Platform version.

SupplyChain enforces immutability

The version of your SupplyChain primitive that is embedded in the name must adhere to the rules described in this section.

A patch update is required to update SupplyChain without an API change. The controller ensures that this rule cannot be broken when comparing SupplyChain primitives on the cluster.

For example, you can apply to a cluster:

• A SupplyChain primitive with the name serverappv1s.example.com-1.0.0 and the kind ServerAppV1s
• A SupplyChain primitive with the name serverappv1s.example.com-1.0.1 and the kind ServerAppV1s

If the generated API for the kind is unchanged, then the later version is accepted. If there is a change, the SupplyChain primitive that was applied first succeeds, and the others reflect the error in their statuses. This rule ensures that you cannot accidentally break the kind API that is running.

These rules ensure that potentially thousands of Workload and Run resources on the cluster do not break.

Recommended version practices:

• If the API and general behavior are unchanged by a change to the spec.stages:
  • Use a patch update, such as 1.2.5 to 1.2.6
  • Keep the same kind, such as ServerAppV1
• If the API is unchanged, but something significantly different occurs because of changes to the spec.stages, consider:
  • Updating the minor or major version, such as 1.2.5 to 1.3.0
  • Updating the kind, such as ServerAppV2
  • Changing the kind, such as ServerAppWithApprovalV1
• If the API changes, consider:
  • Updating the minor or major version, such as 1.2.5 to 1.3.0
  • Updating the kind, such as ServerAppV2

This ensures effective communication to your users. New kind versions typically indicate that the user must migrate their resources to the new API.

Integrity validation

A SupplyChain primitive is not valid if:

• A required field is missing.
• The Component resources referenced are not in the same namespace.
• The Component resources referenced contain values that are not satisfied by their position in spec.stages.
• The name does not match the spec.defines section.
• SupplyChain breaks the versioning rules.

For more information, see status.conditions[].