chore: uds engine installation adr

adr/0006-uds-engine-installation.md

@@ -0,0 +1,51 @@
+# 6. UDS Engine Installation
+
+Date: 10 June 2024
+
+## Status
+
+UNDER REVIEW
+
+## Context
+
+The goal is to establish a method for installing the UDS Engine in a cluster. The chosen approach should be efficient, user-friendly, and compatible with the existing system architecture and workflows.
+
+## Alternatives
+
+### 1. Install UDS Engine as a UDS Core Capability
+This approach involves packaging the UDS Engine in a Zarf package with a Helm chart and deploying it as part of UDS Core.
+
+<b>Pros:</b>
+- UDS Engine is installed as part of UDS Core, ensuring seamless integration.
+- The initial Engine capability depends on Pepr, which is already installed as part of UDS Core.
+
+<b>Cons:</b>
+- UDS Core includes additional capabilities that may not be necessary or desired in all scenarios.
+
+### 2. UDS command
+This alternative proposes a UDS cli command that "bootstraps" a cluster with UDS Engine, similar to how Zarf initializes a cluster with the `zarf init` command.
+
+<b>Pros:</b>
+- This method is quick and lightweight, allowing users to install only UDS Engine in the cluster.
+- It's convenient for rapid development work cycles.
+
+<b>Cons:</b>
+- Users would have to manually install/deploy any other dependencies.
+- There's a potential for maintaining a `uds-cli` command that rarely gets used, once it's run and UDS Engine is installed.
+
+### 3. UDS Core and UDS Dev command
+This strategy proposes integrating UDS Engine as a feature within UDS Core. Additionally, we plan to develop a `uds dev` command to facilitate the Engine's installation. The `uds dev` command is primarily intended for platform engineers who are engaged in development and testing tasks. By designating the installation command as a subcommand of `uds dev`, we underscore that this command is not intended for production environments.
+
+<b>Pros:</b>
+- This method combines the advantages of alternatives 1 and 2 while potentially eliminating the disadvantages.
+
+<b>Cons:</b>
+- It would require more work to maintain two different ways of installing UDS Engine.
+
+## Decision
+
+The chosen option is 3. The plan is to add the UDS Engine as a capability to UDS Core and eventually create a `uds dev` command to install UDS Engine. The initial focus will be on adding UDS Engine as a capability to UDS Core, and the need and implementation for a `uds dev` command will be evaluated later.
+
+## Consequences
+
+Option 3 allows us to concentrate on implementing an initial method for installing the Engine into a cluster. The Zarf package developed for the Engine can be leveraged later for the `uds dev` command. This approach enables quick installation of the Engine into a cluster and allows for the evaluation of the need for a `uds dev` command at a later stage.