Ensure CLI references compatible images

[nojnhuh]

Problem

Currently, the main branch references the latest tagged version for the default images used by the OSM chart (and therefore osm install):

osm/charts/osm/values.yaml

Line 14 in 3fde0f1

tag: v0.8.3

This causes version skew when the main branch is updated but the default image tag stays the same. This becomes an issue when following documentation corresponding to the main branch which refers to new features since the last release and instructions use osm install without overriding the images to images newer than the latest release that implement those features.

Goal

The goal is to come up with a solution such that make build-osm && bin/osm install "just works" in all cases.

To do this, make build-osm would have to become dependent on building and pushing the images used by the control plane, then the CLI would refer to those images by default. The image tag must be unique to maintain a 1:1 mapping of CLI to images.

Solution

Here's one possible implementation I can think of:

1. list docker-push-{init,init-osm-controller,osm-controller,osm-injector} as dependencies of build-osm in the Makefile:
   

   osm/Makefile

   Line 108 in b14458f

   build-osm: check-go-version

   • Ensure the CTR_TAG is set to some deterministic value. The current Git SHA might be close enough, though ideally it would differentiate between dirty and clean worktrees. CTR_REGISTRY can be set to

2. create new package-scoped variables (likely in cmd/cli/install.go) for the tag and registry location of the built images and pass the values to them in the Makefile using the same method as we do for version info:
   

   osm/Makefile

   Line 21 in 3fde0f1

   LDFLAGS ?= "-X $(BUILD_DATE_VAR)=$(BUILD_DATE) -X $(BUILD_VERSION_VAR)=$(VERSION) -X $(BUILD_GITCOMMIT_VAR)=$(GIT_SHA) -X main.chartTGZSource=$$(cat -) -s -w"

3. In the install command, if OpenServiceMesh.image.registry or OpenServiceMesh.image.tag are not overridden via --set, override them with the values of the package-scoped variables defined above. This could be done in this function:
   

   osm/cmd/cli/install.go

   Line 154 in 3fde0f1

   func (i *installCmd) resolveValues() (map[string]interface{}, error) {

   This would still allow users to override the images the standard way per-osm install invocation.

Other things I haven't fully thought through yet

• Installing with helm instead of osm
• images stored in password-protected registries
• Upgrades
• Release builds and maintenance

/cc @shashankram

[nojnhuh]

I opened a draft PR implementing this idea that should be ready to try out: #3380

[shashankram]

Discussed offline with @nojnhuh and there isn't an immediate need for this as the default image tags in main refer to latest-main.