.gitea/workflows/build-edge-node.yml

@@ -38,6 +38,10 @@ jobs:
         run: |
           echo "REPO_NAME=$(echo ${GITHUB_REPOSITORY} | awk -F'/' '{print $2}')" >> $GITHUB_OUTPUT
           echo "VERSION=$(git describe --tags --always | sed 's/^v//')" >> $GITHUB_OUTPUT
+          # Source pin (node-26#19): the git tree hash of the build context.
+          # A node pulls src-<tree of its own checkout> — scripts/image-tags.sh
+          # computes the identical value — so its code and image always match.
+          echo "SRC_TAG=src-$(git rev-parse HEAD:drb-edge-node)" >> $GITHUB_OUTPUT
 
       - uses: docker/build-push-action@v6
         with:
@@ -47,6 +51,7 @@ jobs:
           push: true
           tags: |
             git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:${{ steps.meta.outputs.VERSION }}
+            git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:${{ steps.meta.outputs.SRC_TAG }}
             git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:latest
           cache-from: type=registry,ref=git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:buildcache
           cache-to: type=registry,ref=git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:buildcache,mode=max

.gitea/workflows/build-icecast.yml

@@ -38,6 +38,10 @@ jobs:
         run: |
           echo "REPO_NAME=$(echo ${GITHUB_REPOSITORY} | awk -F'/' '{print $2}')" >> $GITHUB_OUTPUT
           echo "VERSION=$(git describe --tags --always | sed 's/^v//')" >> $GITHUB_OUTPUT
+          # Source pin (node-26#19): the git tree hash of the build context.
+          # A node pulls src-<tree of its own checkout> — scripts/image-tags.sh
+          # computes the identical value — so its code and image always match.
+          echo "SRC_TAG=src-$(git rev-parse HEAD:icecast)" >> $GITHUB_OUTPUT
 
       - uses: docker/build-push-action@v6
         with:
@@ -47,6 +51,7 @@ jobs:
           push: true
           tags: |
             git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:${{ steps.meta.outputs.VERSION }}
+            git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:${{ steps.meta.outputs.SRC_TAG }}
             git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:latest
           cache-from: type=registry,ref=git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:buildcache
           cache-to: type=registry,ref=git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:buildcache,mode=max

.gitea/workflows/build-op25.yml

@@ -38,6 +38,10 @@ jobs:
         run: |
           echo "REPO_NAME=$(echo ${GITHUB_REPOSITORY} | awk -F'/' '{print $2}')" >> $GITHUB_OUTPUT
           echo "VERSION=$(git describe --tags --always | sed 's/^v//')" >> $GITHUB_OUTPUT
+          # Source pin (node-26#19): the git tree hash of the build context.
+          # A node pulls src-<tree of its own checkout> — scripts/image-tags.sh
+          # computes the identical value — so its code and image always match.
+          echo "SRC_TAG=src-$(git rev-parse HEAD:op25-container)" >> $GITHUB_OUTPUT
 
       - uses: docker/build-push-action@v6
         with:
@@ -47,6 +51,7 @@ jobs:
           push: true
           tags: |
             git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:${{ steps.meta.outputs.VERSION }}
+            git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:${{ steps.meta.outputs.SRC_TAG }}
             git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:stable
           # Registry cache — avoids full recompile of GnuRadio/OP25 when only app code changes
           cache-from: type=registry,ref=git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:buildcache

.gitea/workflows/build-secondary-sdr.yml

@@ -38,6 +38,10 @@ jobs:
         run: |
           echo "REPO_NAME=$(echo ${GITHUB_REPOSITORY} | awk -F'/' '{print $2}')" >> $GITHUB_OUTPUT
           echo "VERSION=$(git describe --tags --always | sed 's/^v//')" >> $GITHUB_OUTPUT
+          # Source pin (node-26#19): the git tree hash of the build context.
+          # A node pulls src-<tree of its own checkout> — scripts/image-tags.sh
+          # computes the identical value — so its code and image always match.
+          echo "SRC_TAG=src-$(git rev-parse HEAD:secondary-sdr-container)" >> $GITHUB_OUTPUT
 
       - uses: docker/build-push-action@v6
         with:
@@ -47,6 +51,7 @@ jobs:
           push: true
           tags: |
             git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:${{ steps.meta.outputs.VERSION }}
+            git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:${{ steps.meta.outputs.SRC_TAG }}
             git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:latest
           cache-from: type=registry,ref=git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:buildcache
           cache-to: type=registry,ref=git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${{ steps.meta.outputs.REPO_NAME }}/${{ env.CONTAINER_NAME }}:buildcache,mode=max

.gitea/workflows/release-images.yml

@@ -0,0 +1,87 @@
+name: Release images
+
+# Make sure every node image a release ref needs exists in the registry
+# (node-26#19). A node on `v1` pulls <image>:src-<tree hash of that image's
+# directory at v1>. The per-image build workflows only run when their own
+# directory changes on main, and anything built before #19 has no src- tag at
+# all, so a release tag can point at trees nobody ever built. This fills the
+# gaps: for each image, if src-<tree> is already in the registry it does
+# nothing; otherwise it builds and pushes it (registry cache keeps op25 off a
+# full recompile when only its app code changed).
+#
+# Runs on every v* tag push, including a re-cut `v1`. Also runnable by hand
+# (workflow_dispatch) on any ref — run it once on the ref `v1` points at
+# before re-cutting `v1` onto a commit that contains #19, so nodes never see
+# a moment where their pinned images don't exist yet.
+#
+# Pushes ONLY src- tags. :latest / :stable keep tracking main, as before.
+
+on:
+  workflow_dispatch:
+  push:
+    tags:
+      - "v*"
+
+jobs:
+  ensure:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: edge-node
+            context: drb-edge-node
+          - name: icecast
+            context: icecast
+          - name: op25-client
+            context: op25-container
+          - name: secondary-sdr
+            context: secondary-sdr-container
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: docker/setup-qemu-action@v3
+
+      - uses: docker/setup-buildx-action@v3
+        with:
+          config-inline: |
+            [registry."git.vpn.cusano.net"]
+              http = false
+              insecure = false
+
+      - uses: docker/login-action@v3
+        with:
+          registry: git.vpn.cusano.net
+          username: ${{ gitea.actor }}
+          password: ${{ secrets.BUILD_TOKEN }}
+
+      - name: Resolve source tag
+        id: meta
+        run: |
+          REPO_NAME="$(echo ${GITHUB_REPOSITORY} | awk -F'/' '{print $2}')"
+          # Must match scripts/image-tags.sh and the build-*.yml workflows.
+          IMAGE="git.vpn.cusano.net/${{ vars.DOCKER_ORG }}/${REPO_NAME}/${{ matrix.name }}"
+          TAG="src-$(git rev-parse HEAD:${{ matrix.context }})"
+          echo "IMAGE=$IMAGE" >> $GITHUB_OUTPUT
+          echo "TAG=$TAG" >> $GITHUB_OUTPUT
+          if docker buildx imagetools inspect "$IMAGE:$TAG" >/dev/null 2>&1; then
+            echo "EXISTS=true" >> $GITHUB_OUTPUT
+            echo "$IMAGE:$TAG already published — nothing to do"
+          else
+            echo "EXISTS=false" >> $GITHUB_OUTPUT
+            echo "$IMAGE:$TAG missing — building it"
+          fi
+
+      - if: steps.meta.outputs.EXISTS != 'true'
+        uses: docker/build-push-action@v6
+        with:
+          context: ./${{ matrix.context }}
+          file: ./${{ matrix.context }}/Dockerfile
+          # arm64 only, same as the build-*.yml workflows (node-26#28).
+          platforms: linux/arm64
+          push: true
+          tags: ${{ steps.meta.outputs.IMAGE }}:${{ steps.meta.outputs.TAG }}
+          cache-from: type=registry,ref=${{ steps.meta.outputs.IMAGE }}:buildcache

.gitignore

@@ -13,6 +13,7 @@ venv/
 # Runtime-generated configs and recordings
 configs/
 recordings/
+.drb-update-compose.yml
 
 # Logs
 *.log

docker-compose.yml

@@ -1,6 +1,10 @@
+# Image tags: a provisioned node pins every image to the source tree it has
+# checked out (DRB_TAG_* = src-<git tree hash>, written into .env by install.sh
+# and scripts/drb-update.sh via scripts/image-tags.sh — node-26#19). Unset, as
+# in local dev, they fall back to :latest / :stable, which CI builds from main.
 services:
   icecast:
-    image: ${IMAGE_REGISTRY:-git.vpn.cusano.net}/${DOCKER_ORG:-logan}/${DOCKER_REPO:-node-26}/icecast:latest
+    image: ${IMAGE_REGISTRY:-git.vpn.cusano.net}/${DOCKER_ORG:-logan}/${DOCKER_REPO:-node-26}/icecast:${DRB_TAG_ICECAST:-latest}
     build: ./icecast
     restart: unless-stopped
     network_mode: host
@@ -16,7 +20,7 @@ services:
   # rather than being exposed. edge-node still reaches both over localhost
   # because it shares this host network namespace.
   op25:
-    image: ${IMAGE_REGISTRY:-git.vpn.cusano.net}/${DOCKER_ORG:-logan}/${DOCKER_REPO:-node-26}/op25-client:stable
+    image: ${IMAGE_REGISTRY:-git.vpn.cusano.net}/${DOCKER_ORG:-logan}/${DOCKER_REPO:-node-26}/op25-client:${DRB_TAG_OP25:-stable}
     build: ./op25-container
     restart: unless-stopped
     privileged: true
@@ -38,7 +42,7 @@ services:
   # node-26#9. Same network/device access as op25 for the same reason: it
   # needs the raw USB device, not a virtualized one.
   secondary-sdr:
-    image: ${IMAGE_REGISTRY:-git.vpn.cusano.net}/${DOCKER_ORG:-logan}/${DOCKER_REPO:-node-26}/secondary-sdr:latest
+    image: ${IMAGE_REGISTRY:-git.vpn.cusano.net}/${DOCKER_ORG:-logan}/${DOCKER_REPO:-node-26}/secondary-sdr:${DRB_TAG_SECONDARY_SDR:-latest}
     build: ./secondary-sdr-container
     restart: unless-stopped
     privileged: true
@@ -48,7 +52,7 @@ services:
       - /dev:/dev
 
   edge-node:
-    image: ${IMAGE_REGISTRY:-git.vpn.cusano.net}/${DOCKER_ORG:-logan}/${DOCKER_REPO:-node-26}/edge-node:latest
+    image: ${IMAGE_REGISTRY:-git.vpn.cusano.net}/${DOCKER_ORG:-logan}/${DOCKER_REPO:-node-26}/edge-node:${DRB_TAG_EDGE_NODE:-latest}
     build: ./drb-edge-node
     restart: unless-stopped
     network_mode: host

drb-edge-node/tests/test_host_updater.py

@@ -24,21 +24,37 @@ pytestmark = pytest.mark.skipif(
 )
 
 REPO = "https://git.example.net/logan/node-26.git"
-OLD, NEW = "a" * 40, "b" * 40
+OLD, NEW, TREE = "a" * 40, "b" * 40, "c" * 40
+REPO_ROOT = SCRIPT.parents[1]
 
 STUB_GIT = r'''#!/usr/bin/env bash
 echo "git $*" >> "$STUB/calls"
-while [ "$1" = -c ]; do shift 2; done
+while [ "$1" = -c ] || [ "$1" = -C ]; do shift 2; done
 case "$1" in
-  rev-parse) if [ "$2" = HEAD ]; then cat "$STUB/head"; else echo "$STUB_NEW"; fi ;;
+  rev-parse)
+    if [ "$2" = HEAD ]; then cat "$STUB/head"
+    elif [ "$2" = --verify ]; then echo "$STUB_TREE"   # tree hash of <commit>:<dir>
+    else echo "$STUB_NEW"; fi ;;
   remote) echo "$STUB_ORIGIN" ;;
   fetch) exit 0 ;;
   show-ref) [ "$4" = "refs/tags/v1" ] ;;
+  cat-file) [ -z "${STUB_NO_PIN:-}" ] ;;   # target has scripts/image-tags.sh
+  show) case "$2" in
+          *:scripts/image-tags.sh) cat "$STUB_REPO/scripts/image-tags.sh" ;;
+          *:docker-compose.yml) cat "$STUB_REPO/docker-compose.yml" ;;
+        esac ;;
   checkout) echo "${@: -1}" > "$STUB/head" ;;
   *) exit 0 ;;
 esac
 '''
-STUB_DOCKER = '#!/usr/bin/env bash\necho "docker $*" >> "$STUB/calls"\n'
+STUB_DOCKER = r'''#!/usr/bin/env bash
+echo "docker $*" >> "$STUB/calls"
+case "$*" in
+  *"config --images"*) echo "reg.example/edge-node:$STUB_PULLED_TAG" ;;
+  "image inspect"*) [ -z "${STUB_MISSING_IMAGE:-}" ] || exit 1 ;;
+esac
+exit 0
+'''
 STUB_CURL = r'''#!/usr/bin/env bash
 echo "curl $*" >> "$STUB/calls"
 for a in "$@"; do case "$a" in @*) cat "${a#@}" >> "$STUB/headers" ;; esac; done
@@ -79,6 +95,7 @@ def env(tmp_path):
     e.update({
         "PATH": f"{bindir}:{os.environ['PATH']}",
         "STUB": str(stub), "STUB_NEW": NEW, "STUB_ORIGIN": REPO,
+        "STUB_TREE": TREE, "STUB_REPO": str(REPO_ROOT), "STUB_PULLED_TAG": f"src-{TREE}",
         "DRB_UPDATER_CONF": str(conf),
         "DRB_UPDATER_STATE": str(tmp_path / "state"),
         "DRB_UPDATER_LOCK": str(tmp_path / "lock"),
@@ -94,6 +111,10 @@ def _calls(env):
     return (env["stub"] / "calls").read_text()
 
 
+def _pulled(calls: str) -> bool:
+    return any(line.startswith("docker compose ") and line.endswith(" pull") for line in calls.splitlines())
+
+
 def test_no_request_means_checkin_only(env):
     r = _run(env)
     assert r.returncode == 0, r.stderr
@@ -108,7 +129,7 @@ def test_c2_request_updates_once_and_reports(env):
     r = _run(env)
     assert r.returncode == 0, r.stderr + r.stdout
     calls = _calls(env)
-    assert "docker compose pull" in calls
+    assert _pulled(calls)
     assert "docker compose up -d --no-build --force-recreate --remove-orphans" in calls
     assert (env["stub"] / "head").read_text().strip() == NEW
     assert '"applied_request_at":"2026-10-04T12:00:00+00:00"' in calls
@@ -126,7 +147,7 @@ def test_mqtt_sentinel_triggers_update_and_is_consumed(env):
     assert r.returncode == 0, r.stderr
     assert not sentinel.exists()
     calls = _calls(env)
-    assert "docker compose pull" in calls
+    assert _pulled(calls)
     assert "evil" not in calls and "rm -rf" not in calls
 
 
@@ -153,7 +174,7 @@ def test_refuses_when_env_registry_differs(env):
     (env["inst"] / "configs" / "update-requested").write_text("")
     r = _run(env)
     assert r.returncode != 0
-    assert "docker compose pull" not in _calls(env)
+    assert not _pulled(_calls(env))
 
 
 def test_non_https_repo_in_conf_is_rejected(env):
@@ -177,3 +198,42 @@ def test_plain_http_c2_skips_checkin(env):
     r = _run(env)
     assert r.returncode == 0
     assert "curl" not in _calls(env)
+
+
+# ── node-26#19: images pinned to the target's source tree ─────────────────
+
+def test_pins_images_and_pulls_before_checkout(env):
+    (env["inst"] / "configs" / "update-requested").write_text("")
+    r = _run(env)
+    assert r.returncode == 0, r.stderr + r.stdout
+    lines = _calls(env).splitlines()
+    pull = next(i for i, ln in enumerate(lines) if ln.startswith("docker compose ") and ln.endswith(" pull"))
+    checkout = next(i for i, ln in enumerate(lines) if ln.startswith("git") and " checkout " in ln)
+    assert pull < checkout, "images must be pulled before the new code is checked out"
+    dotenv = (env["inst"] / ".env").read_text()
+    for var in ("DRB_TAG_EDGE_NODE", "DRB_TAG_OP25", "DRB_TAG_ICECAST", "DRB_TAG_SECONDARY_SDR"):
+        assert f"{var}=src-{TREE}\n" in dotenv
+    assert dotenv.startswith("NODE_ID=node-7\n")  # existing lines kept
+    assert not (env["inst"] / ".drb-update-compose.yml").exists()
+
+
+def test_missing_pinned_image_changes_nothing(env):
+    env["env"]["STUB_MISSING_IMAGE"] = "1"
+    (env["inst"] / "configs" / "update-requested").write_text("")
+    r = _run(env)
+    assert r.returncode != 0
+    assert (env["stub"] / "head").read_text().strip() == OLD
+    calls = _calls(env)
+    assert " checkout " not in calls
+    assert "up -d" not in calls
+    assert "DRB_TAG_" not in (env["inst"] / ".env").read_text()
+
+
+def test_target_without_pinning_still_updates(env):
+    env["env"]["STUB_NO_PIN"] = "1"
+    (env["inst"] / "configs" / "update-requested").write_text("")
+    r = _run(env)
+    assert r.returncode == 0, r.stderr + r.stdout
+    assert (env["stub"] / "head").read_text().strip() == NEW
+    assert _pulled(_calls(env))
+    assert "DRB_TAG_" not in (env["inst"] / ".env").read_text()

install.sh

@@ -10,7 +10,7 @@
 #  --track-main for the owner's own always-latest nodes)
 #
 # Hosting, the pinned ref, and setup.sh's retirement are settled (owner
-# decisions, 2026-09-06). One standing hazard remains — D3 below.
+# decisions, 2026-09-06). D3 below is mitigated by image pinning (node-26#19).
 #
 # What it does, in order:
 #   1. Preflight (root, arch, apt, SDR present)
@@ -48,15 +48,18 @@
 #       the mint panel / node-26#4). DEFAULT_REF below is `v1`. `--track-main`
 #       stays as an opt-in for the owner's own nodes.
 #
-# STANDING HAZARD
+# MITIGATED HAZARD
 #
 #   D3  SOURCE-OVERLAY. docker-compose.yml bind-mounts ./drb-edge-node/app and
-#       ./op25-container/app OVER the image's /app. So even in prebuilt mode
+#       ./op25-container/app OVER the image's /app, so the running Python is
-#       the running Python is the CLONED REF's code against the pulled image's
+#       the CLONED REF's code against the pulled image's dependencies. Those
-#       dependencies. `v1` == the commit CI built the current :latest/:stable
+#       used to be :latest/:stable, built from main — silently a different
-#       from, so today they match — but the moment `v1` and the image tags
+#       commit from `v1`. Since node-26#19 every image is pinned to
-#       diverge this silently mixes them. Fix: drop those two mounts from the
+#       src-<git tree hash of its own directory at the checked-out ref>
-#       prod compose path, or always retag images from the same ref as `v1`.
+#       (scripts/image-tags.sh, written into .env as DRB_TAG_*), which CI tags
+#       identically. The mounts now overlay the same code the image was built
+#       from. A pinned image that was never built fails the pull loudly; the
+#       "Release images" workflow builds any a release tag is missing.
 # ---------------------------------------------------------------------------
 set -euo pipefail
 
@@ -334,6 +337,20 @@ EOF
   ok ".env written for '$NODE_ID'"
 fi
 
+# Pin every image to the source just checked out (node-26#19, D3). Written
+# into .env — fresh or preserved — so later manual `docker compose` runs on
+# this node use the same pins.
+# A --ref older than #19 has no helper; its compose file hardcodes its tags.
+if [ -f "$INSTALL_DIR/scripts/image-tags.sh" ]; then
+  # shellcheck source=scripts/image-tags.sh
+  . "$INSTALL_DIR/scripts/image-tags.sh"
+  drb_pin_image_tags "$INSTALL_DIR/.env" "$INSTALL_DIR" "$RESOLVED_SHA" || die "could not write image pins to .env"
+  ok "images pinned to the source at ${RESOLVED_SHA:0:12} (DRB_TAG_* in .env)"
+else
+  warn "$REF predates image pinning (node-26#19) — using its compose file's default image tags"
+  drb_images_present() { return 0; }
+fi
+
 # ── 5. Enrollment ───────────────────────────────────────────────────────────
 # Client half of Server/drb-c2-core/app/routers/enrollment.py. It does NOT
 # exist in the edge-node app today (mqtt_manager.py:73-85 says so explicitly),
@@ -570,6 +587,11 @@ if [ "$DO_START" = 1 ]; then
   requirement or a transient network error: re-run with DRB_REGISTRY_USER /
   DRB_REGISTRY_PASS set, or with --build to compile on the Pi (~1h for op25)."
     fi
+    # compose pull only WARNS for a missing image that also has a build:
+    # section, so check the pinned images really arrived.
+    drb_images_present || die "the images pinned to $REF (${RESOLVED_SHA:0:12}) are not in
+  $REGISTRY yet. CI may still be building them — wait and re-run; the owner can
+  run the 'Release images' workflow on that ref; or re-run with --build."
     docker compose up --no-build -d
   fi
   # ALWAYS recreate edge-node (node-26#14): `up -d` leaves an already-running

scripts/drb-update.sh

@@ -17,7 +17,9 @@
 #   * Node credentials go to curl via a 0600 header file, never argv.
 #   * C2 must be https.
 # What this does NOT defend against: a compromised git host or registry —
-# refs and images are not signed (see the issue filed with node-26#15).
+# refs and images are not signed (node-26#17).
+#   * Images are pinned to the checked-out source (node-26#19): each one is
+#     pulled as src-<git tree hash of its build directory>, never :latest.
 #
 # The whole body is inside main(), called on the last line: bash parses the
 # function completely before running it, so `git checkout` replacing this
@@ -146,6 +148,47 @@ do_update() {
   fi
   local old new
   old="$(git rev-parse HEAD)"; new="$(git rev-parse "$target^{commit}")"
+
+  local env_registry
+  env_registry="$(grep -E '^IMAGE_REGISTRY=' .env | head -1 | cut -d= -f2- | tr -d '"' || true)"
+  [ "${env_registry:-git.vpn.cusano.net}" = "$REGISTRY" ] \
+    || { err ".env IMAGE_REGISTRY '$env_registry' != configured '$REGISTRY' — refusing"; return 1; }
+
+  # Image pins for the TARGET commit (node-26#19): each image is tagged with
+  # the git tree hash of its own source directory, so the images always match
+  # the code being checked out. The helper is read from the target commit so
+  # its service list matches the target's compose file.
+  # Read into a variable, not `source <(...)`: a failed `git show` must leave
+  # pin=0 rather than "succeed" with no functions defined.
+  local pin=0 helper
+  if git cat-file -e "$new:scripts/image-tags.sh" 2>/dev/null; then
+    helper="$(git show "$new:scripts/image-tags.sh")" && [ -n "$helper" ] && eval "$helper" \
+      && declare -F drb_image_tags drb_images_present drb_pin_image_tags >/dev/null && pin=1
+  fi
+  [ "$pin" = 1 ] || log "target ${new:0:12} predates image pinning — using its compose file's default tags"
+
+  if [ "$BUILD" != 1 ]; then
+    # Pull BEFORE checkout. The app code is bind-mounted from the checkout
+    # (install.sh D3) and edge-node runs uvicorn --reload, so checking out first
+    # would run the new code on the old images for as long as the pull takes —
+    # or for good, if the pinned images don't exist. Pulling against the
+    # target's own compose file means a failed pull changes nothing. It is
+    # written next to the real one so its relative paths (.env, env_file,
+    # build contexts) resolve exactly the same way.
+    local tfile="$INSTALL_DIR/.drb-update-compose.yml" pulled=0
+    git show "$new:docker-compose.yml" > "$tfile" || { rm -f "$tfile"; return 1; }
+    local -a tc=(-f "$tfile" --project-directory "$INSTALL_DIR")
+    (
+      if [ "$pin" = 1 ]; then
+        while IFS= read -r l; do export "$l"; done < <(drb_image_tags "$INSTALL_DIR" "$new")
+      fi
+      docker compose "${tc[@]}" pull || exit 1
+      if [ "$pin" = 1 ]; then drb_images_present "${tc[@]}" || exit 1; fi
+    ) && pulled=1
+    rm -f "$tfile"
+    [ "$pulled" = 1 ] || { err "images for ${new:0:12} are not available — nothing changed (CI may still be building them; the 'Release images' workflow publishes any that are missing)"; return 1; }
+  fi
+
   if [ "$old" != "$new" ]; then
     git -c advice.detachedHead=false checkout --force --detach "$new" || return 1
     log "checked out $REF: ${old:0:12} -> ${new:0:12}"
@@ -153,19 +196,28 @@ do_update() {
     bash scripts/install-updater.sh --refresh || log "unit refresh failed (continuing with the old units)"
   fi
 
-  local env_registry
+  if [ "$pin" = 1 ]; then
-  env_registry="$(grep -E '^IMAGE_REGISTRY=' .env | head -1 | cut -d= -f2- | tr -d '"' || true)"
+    drb_pin_image_tags "$INSTALL_DIR/.env" "$INSTALL_DIR" "$new" || { err "could not write image pins to .env"; return 1; }
-  [ "${env_registry:-git.vpn.cusano.net}" = "$REGISTRY" ] \
+  fi
-    || { err ".env IMAGE_REGISTRY '$env_registry' != configured '$REGISTRY' — refusing"; return 1; }
 
   if [ "$BUILD" = 1 ]; then
-    docker compose build || return 1
+    docker compose build || return 1   # tags the local builds with the same pins
-  else
-    docker compose pull || return 1
   fi
   # --force-recreate: app code is bind-mounted from the checkout (install.sh
   # D3), so a code-only change also needs every container restarted.
   docker compose up -d --no-build --force-recreate --remove-orphans || return 1
+
+  # Drop pinned images this node no longer runs. `image prune` only removes
+  # dangling images, and every previous src- tag is still tagged. `image rm`
+  # without -f refuses anything a container still uses.
+  if [ "$pin" = 1 ]; then
+    local keep ref
+    keep="$(drb_image_tags "$INSTALL_DIR" "$new" | cut -d= -f2)"
+    docker images --format '{{.Repository}}:{{.Tag}}' | grep -E ':src-[0-9a-f]{40}$' \
+      | while IFS= read -r ref; do
+          grep -qxF "${ref##*:}" <<< "$keep" || docker image rm "$ref" >/dev/null 2>&1 || true
+        done || true
+  fi
   docker image prune -f >/dev/null 2>&1 || true
 }
 

scripts/image-tags.sh

@@ -0,0 +1,65 @@
+# shellcheck shell=bash
+#
+# Pin each node image to the exact source it was built from (node-26#19).
+# Sourced by install.sh and scripts/drb-update.sh; not run directly.
+#
+# The tag is the git TREE hash of the image's build context, `src-<tree>`.
+# CI computes the same value (`git rev-parse HEAD:<dir>` in the build
+# workflows), so a node asks for the image built from the very directory it
+# has checked out. That is exact even though each image is only rebuilt when
+# its own directory changes: an unchanged directory keeps the same tree hash,
+# and so the same image, across commits. :latest / :stable still exist for
+# local dev; a provisioned node never uses them.
+#
+# docker-compose.yml reads these as ${DRB_TAG_*:-latest}. The values live in
+# .env so every manual `docker compose ...` on the node sees the same pins.
+
+# VAR:build-context-dir, one per compose service with an image.
+DRB_IMAGE_SOURCES="DRB_TAG_ICECAST:icecast DRB_TAG_OP25:op25-container \
+DRB_TAG_SECONDARY_SDR:secondary-sdr-container DRB_TAG_EDGE_NODE:drb-edge-node"
+
+# drb_image_tags REPO_DIR COMMIT -> "VAR=src-<tree>" lines. A directory that
+# does not exist at COMMIT is skipped (its compose file won't reference it).
+drb_image_tags() {
+  local _p _var _dir _tree
+  for _p in $DRB_IMAGE_SOURCES; do
+    _var="${_p%%:*}"; _dir="${_p#*:}"
+    _tree="$(git -C "$1" rev-parse --verify -q "$2:$_dir" 2>/dev/null)" || continue
+    printf '%s=src-%s\n' "$_var" "$_tree"
+  done
+}
+
+# drb_env_set ENV_FILE KEY VALUE — replace KEY's line in place, or append it.
+# Rewrites through the same inode so .env keeps its 0600 mode and owner.
+drb_env_set() {
+  local _tmp; _tmp="$(mktemp)"
+  awk -v k="$2" -v v="$3" '
+    index($0, k "=") == 1 { if (!done) print k "=" v; done = 1; next }
+    { print }
+    END { if (!done) print k "=" v }' "$1" > "$_tmp" && cat "$_tmp" > "$1"
+  local _rc=$?; rm -f "$_tmp"; return $_rc
+}
+
+# drb_pin_image_tags ENV_FILE REPO_DIR COMMIT — write the pins into .env and
+# export them, so compose sees them whether or not it re-reads .env.
+drb_pin_image_tags() {
+  local _line
+  while IFS= read -r _line; do
+    drb_env_set "$1" "${_line%%=*}" "${_line#*=}" || return 1
+    export "$_line"
+  done < <(drb_image_tags "$2" "$3")
+}
+
+# drb_images_present COMPOSE_ARGS... — 0 if every image the compose project
+# names is in the local image store. `compose pull` only WARNS when a service
+# that also has a build: section fails to pull, so its exit code alone does
+# not prove the pinned images exist.
+drb_images_present() {
+  local _imgs _img _missing=0
+  _imgs="$(docker compose "$@" config --images)" || return 1
+  while IFS= read -r _img; do
+    [ -n "$_img" ] || continue
+    docker image inspect "$_img" >/dev/null 2>&1 || { printf 'missing image: %s\n' "$_img" >&2; _missing=1; }
+  done <<< "$_imgs"
+  return $_missing
+}