refactor: unify images into calicovpp/vpp and flatten repo layout

[aritrbas]

Summary:

This PR does two related things on the path to CalicoVPP release/v3.33.0:

1. Unifies dataplane images and flattens the repo layout - consolidates calicovpp/agent, calicovpp/vpp, calicovpp/multinet-monitor and calicovpp/init-eks into a single calicovpp/vpp image and moves libraries under pkg/ with entrypoints under cmd/.
2. Introduces a kustomize-based VPP kube-test integration - CalicoVPP now owns the VPP kube-test manifest and exposes a small Makefile API so VPP kube-test (and other consumers) no longer need to know CalicoVPP internal layout details (image names, in-repo VPP build paths, etc.).

Runtime behavior is unchanged - the agent and VPP still run as separate containers; the agent container reuses calicovpp/vpp with an explicit command: ["/bin/calico-vpp-agent"] override.

Changes:

• Unified image: calicovpp/vpp (contains all dataplane binaries)
• Single env var: CALICO_VPP_IMAGE (replaces CALICO_AGENT_IMAGE, CALICO_VPP_IMAGE, MULTINET_MONITOR_IMAGE)
• calicovpp/vclsidecar and calicovpp/ctl remain separate images
• Unified Dockerfiles (images/ubuntu/Dockerfile, Dockerfile.debug) ship all binaries: calico-vpp-agent, felix-api-proxy, gobgp, multinet-monitor, vpp-manager and init-eks scripts under images/ubuntu/bin/
• Top-level Makefile delegates image build through pkg/vpp-manager
• pkg/vpp-manager/Makefile builds all Go binaries into the unified image
• Per-component image/push targets removed from agent and multinet-monitor Makefiles
• Manifests updated to calicovpp/vpp with explicit command overrides for agent and multinet-monitor containers
• Path references in test/ and docs/ updated for pkg/ move
• Image contexts moved to top-level images/
• Helper scripts moved to top-level scripts/
• VPP clone/build directory moved to top-level vpp_build/

Directory Restructure:

├── cmd
│ ├── api-proxy
│ ├── calico-vpp-agent
│ ├── calicovppctl
│ ├── multinet-monitor
│ ├── replay-trace
│ └── vpp-manager
├── common.mk
├── docs
├── images
├── Makefile
├── pkg
│ ├── calico-vpp-agent
│ ├── config
│ ├── multinet-monitor
│ ├── vpplink
│ └── vpp-manager
├── scripts
├── test
├── vpp_build
└── yaml

VPP kube-test integration:

CalicoVPP now owns the kube-test manifest as kustomize sources under yaml/components/kube-test/ and yaml/overlays/kube-test-{kind,baremetal}/. Layout-specific values (unified image name, agent command override, VPP build path vpp_build/, registry/pull-policy) are baked into the component patches.

Only consumer-owned runtime placeholders survive in the emitted manifest:

Placeholder	Owner / typical source
${CALICOVPP_VERSION}	image tag (kt-master, v3.32.0, …)
${HOME}	host path for calicovpp checkout bind mount
${ADDITIONAL_VPP_CONFIG}	per-test extra VPP startup CLI
${CALICOVPP_ENABLE_MEMIF}	per-test memif feature toggle
${CALICO_NETWORK_CONFIG}	per-test calico-network override
${CALICOVPP_INTERFACE}	baremetal-only: uplink NIC name

kustomize layout:

• yaml/components/kube-test/ — shared kube-test component (daemonset patch, configmap defaults, tigera-operator snippet)
• yaml/components/kube-test/kind/ — kind adjustments (eth0, af_packet, no hugepages)
• yaml/components/kube-test/baremetal/ — baremetal adjustments (DPDK uplink, hugepages, larger CPU/buffer pool, docker.io registry)
• yaml/overlays/kube-test-{kind,baremetal}/ — wires the base daemonset and the kube-test components.
• yaml/generated/calico-vpp-kubetest.yaml — checked-in kind flavor output; baremetal is built on demand
• yaml/Makefile — regenerates the kind kubetest yaml and sanity-checks the baremetal overlay

The tigera-operator Installation/APIServer CRs are not kustomize resources (they embed ${CALICO_NETWORK_CONFIG}, which is invalid YAML until envsubst runs). They are appended verbatim by make kube-test-template from yaml/components/kube-test/tigera-installation.snippet.yaml.

Makefile API (consumed by VPP kube-test)

Target	Purpose
make vpp [VPP_DIR=…] [BASE=…]	Build VPP; delegates to pkg/vpp-manager
make kube-test-template FLAVOR={kind,baremetal}	Emit fully-resolved kube-test manifest
make kube-test-push-images CALICOVPP_VERSION=…	Pull/tag/push images to local kind registry

KUBE_TEST_IMAGES defaults to calicovpp/vpp on this branch (unified layout). Older split-image release branches backport this with default value calicovpp/vpp calicovpp/agent calicovpp/multinet-monitor.

Benefits:

• Single image tag to manage across all dataplane components.
• Reduced bandwidth and storage requirements.
• No risk of image version drift between components.
• Simplified CI/CD pipeline.
• Easier version management and releases.
• Clear separation between CalicoVPP (layout owner) and VPP kube-test (consumer of generic Makefile).
• kind and baremetal kube-test flavors supported from the same kustomize base.

VPP kube-test PR:

• 45705: kube-test: support CalicoVPP repo restructure (backward-compatible) | https://gerrit.fd.io/r/c/vpp/+/45705

calicovpp-deployments PR:

• refactor: update Makefile for unified calicovpp/vpp image

[sknat]

looks neat ! Thanks a bunch for putting this together

[sknat]

lgtm