feat(ci): allow routing apt traffic through an alternate Ubuntu mirror (#9650)

* feat(ci): allow routing apt traffic through an alternate Ubuntu mirror

Adds opt-in APT_MIRROR / APT_PORTS_MIRROR knobs to all Dockerfiles, the
Makefile, and CI workflows so we can fail over to a non-canonical Ubuntu
mirror when archive.ubuntu.com / security.ubuntu.com / ports.ubuntu.com
are degraded (recently observed: multi-day DDoS against the default pool).

Defaults are empty everywhere — behavior is unchanged unless a mirror is
configured. To enable in CI, set the repo-level GitHub Actions variables
APT_MIRROR (and APT_PORTS_MIRROR for arm64 builds). Locally:
    make docker APT_MIRROR=http://azure.archive.ubuntu.com

A small POSIX-sh helper in .docker/apt-mirror.sh rewrites both DEB822
(/etc/apt/sources.list.d/ubuntu.sources, Ubuntu 24.04+) and the legacy
/etc/apt/sources.list before the first apt-get update. Dockerfile stages
load it via RUN --mount=type=bind, so there is no extra layer and no
cache invalidation when the script is unchanged. Reusable workflows also
rewrite the runner's own /etc/apt sources before any sudo apt-get call.

Assisted-by: Claude:claude-opus-4-7[1m] [Claude Code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* ci(apt-mirror): default to the Azure mirror, visible in the workflow source

Bakes Azure (http://azure.archive.ubuntu.com / http://azure.ports.ubuntu.com)
in as the default for both Docker builds and runner-side apt — rather than
hiding the URL behind a GitHub Actions repo variable that's not visible
from the source tree.

A new composite action at .github/actions/configure-apt-mirror is the
single source of truth for runner-side rewrites. Five standalone
workflows (build-test, release, tests-e2e, tests-ui-e2e, update_swagger)
just `uses: ./.github/actions/configure-apt-mirror`.

Three workflows (image_build, backend_build, checksum_checker) keep an
inline bash rewrite, because they install/upgrade git via apt *before*
the checkout step (so the local composite action isn't loadable yet).
The Azure URL is visible in those files too.

The `apt-mirror` / `apt-ports-mirror` inputs of the reusable workflows
keep their now-Azure defaults — they still feed the Docker build-args
block in addition to the inline runner-side rewrite. Callers (image.yml,
image-pr.yml, backend.yml, backend_pr.yml) drop the previous
`vars.APT_MIRROR` plumbing and rely on those defaults.

Assisted-by: Claude:claude-opus-4-7[1m] [Claude Code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* ci(apt-mirror): drop Force Install GIT, consolidate on the composite action

The PPA git upgrade ran add-apt-repository ppa:git-core/ppa, which talks
to api.launchpad.net — also part of Canonical's infrastructure and
currently returning HTTP 504. The Azure mirror only covers
archive.ubuntu.com / security.ubuntu.com / ports.ubuntu.com, not PPAs.

The system git that ubuntu-latest already ships is sufficient for
actions/checkout and the build pipeline, so just drop the upgrade. With
that gone, the apt-before-checkout constraint disappears too — all three
holdouts (image_build, backend_build, checksum_checker) can now switch
to ./.github/actions/configure-apt-mirror like the other five.

Net: 0 inline apt-mirror blocks, all 8 workflows route through the
composite action.

Assisted-by: Claude:claude-opus-4-7[1m] [Claude Code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

---------

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

.github/workflows/image_build.yml

@@ -56,6 +56,16 @@ on:
         required: false
         default: 'noble'
         type: string
+      apt-mirror:
+        description: 'Replacement URL for archive.ubuntu.com / security.ubuntu.com (empty = use upstream)'
+        required: false
+        default: 'http://azure.archive.ubuntu.com'
+        type: string
+      apt-ports-mirror:
+        description: 'Replacement URL for ports.ubuntu.com (arm64 etc., empty = use upstream)'
+        required: false
+        default: 'http://azure.ports.ubuntu.com'
+        type: string
     secrets:
       dockerUsername:
         required: true
@@ -70,6 +80,15 @@ jobs:
     runs-on: ${{ inputs.runs-on }}
     steps:
 
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Configure apt mirror on runner
+        uses: ./.github/actions/configure-apt-mirror
+        with:
+          mirror: ${{ inputs.apt-mirror }}
+          ports-mirror: ${{ inputs.apt-ports-mirror }}
+
       - name: Free Disk Space (Ubuntu)
         if: inputs.runs-on == 'ubuntu-latest'
         uses: jlumbroso/free-disk-space@main
@@ -85,16 +104,6 @@ jobs:
           large-packages: true
           docker-images: true
           swap-storage: true
-      - name: Force Install GIT latest
-        run: |
-          sudo apt-get update \
-          && sudo apt-get install -y software-properties-common \
-          && sudo apt-get update \
-          && sudo add-apt-repository -y ppa:git-core/ppa \
-          && sudo apt-get update \
-          && sudo apt-get install -y git
-      - name: Checkout
-        uses: actions/checkout@v6
 
       - name: Release space from worker
         if: inputs.runs-on == 'ubuntu-latest'
@@ -205,6 +214,8 @@ jobs:
             SKIP_DRIVERS=${{ inputs.skip-drivers }}
             UBUNTU_VERSION=${{ inputs.ubuntu-version }}
             UBUNTU_CODENAME=${{ inputs.ubuntu-codename }}
+            APT_MIRROR=${{ inputs.apt-mirror }}
+            APT_PORTS_MIRROR=${{ inputs.apt-ports-mirror }}
           context: .
           file: ./Dockerfile
           cache-from: type=registry,ref=quay.io/go-skynet/ci-cache:cache-localai${{ inputs.tag-suffix }}
@@ -228,6 +239,8 @@ jobs:
             SKIP_DRIVERS=${{ inputs.skip-drivers }}
             UBUNTU_VERSION=${{ inputs.ubuntu-version }}
             UBUNTU_CODENAME=${{ inputs.ubuntu-codename }}
+            APT_MIRROR=${{ inputs.apt-mirror }}
+            APT_PORTS_MIRROR=${{ inputs.apt-ports-mirror }}
           context: .
           file: ./Dockerfile
           cache-from: type=registry,ref=quay.io/go-skynet/ci-cache:cache-localai${{ inputs.tag-suffix }}