fix(deploy): Hotfix #18 — apt-get retry loop in libest Dockerfile (transient mirror flake)

CI image-and-supply-chain job failed building deploy/test/libest/
Dockerfile:

  Get:62 http://deb.debian.org/debian bullseye/main amd64 libssh2-1
        amd64 1.9.0-2+deb11u1 [156 kB]
  Err:62 http://deb.debian.org/debian bullseye/main amd64 libssh2-1
        amd64 1.9.0-2+deb11u1
    Error reading from server - read (104: Connection reset by peer)
    [IP: 151.101.202.132 80]
  E: Failed to fetch http://deb.debian.org/debian/pool/main/libs/
     libssh2/libssh2-1_1.9.0-2%2bdeb11u1_amd64.deb
  E: Unable to fetch some archives, maybe run apt-get update or try
     with --fix-missing?

Root cause:
  Transient TCP reset from fastly's Debian mirror at 151.101.202.132
  mid-fetch of one of 73 packages. Mirrors flake; the apt error
  message itself suggests "--fix-missing." This was NOT a code
  regression — the build sequence completed Dockerfile (main
  server), Dockerfile.agent, and f5-mock-icontrol/Dockerfile cleanly
  before hitting the flake on the 4th and final Dockerfile. The Go
  + npm steps for the main image all succeeded.

  The main Dockerfile already wraps `npm ci` in a 3-retry loop
  (Hotfix #9 from the Storybook lockfile saga; npm registry has the
  same flake profile as Debian mirrors). The libest Dockerfile's
  two apt-get install sites (builder stage line 85, runtime stage
  line 189) had no such wrapping.

Fix:
  Wrap both apt-get install invocations in a 3-retry loop matching
  the main Dockerfile's npm-ci pattern. Each retry runs
  `apt-get update && apt-get install --fix-missing ...`, exits the
  loop on success, sleeps 5s between attempts. After 3 failed
  attempts the build fails (preserves CI's signal for a genuinely
  broken mirror state).

  --fix-missing telling apt to continue past temporarily-missing
  packages on subsequent retries; combined with the update + sleep,
  the 3-attempt loop covers the typical mirror-flake window
  (~30-60s of churn before another mirror takes over).

  Both apt-get sites in the libest Dockerfile get the same treatment
  (builder + runtime). The two are independent install operations
  so failure in one is independent of the other.

Verification (sandbox):
  • Visual diff of both apt-get blocks — consistent retry shape +
    --fix-missing + error message + sleep cadence
  • No Go-side code touched; this is a pure CI-infrastructure
    Dockerfile change
  • Other Dockerfiles in the repo (main + agent + f5-mock-icontrol)
    don't need this fix today; the main Dockerfile already has
    the retry loop for npm ci, and agent + f5-mock use Alpine `apk`
    which has its own retry semantics

Ground-truth: origin/master tip 7268d12 (FE-M6 just pushed)
verified via GitHub API BEFORE commit.

Falsifiable proof for the next CI run: the image-and-supply-chain
job's libest build should either succeed on first attempt OR retry
through the flake automatically. The expected outcome is a green
build; a real broken-mirror state would still fail after 3
attempts (which is the right signal).

deploy/test/libest/Dockerfile

@@ -82,16 +82,30 @@ ARG LIBEST_REF
 # is the same major version libest r3.2.0 was tested against. libest
 # also wants libcurl + libsafec; we install both via apt rather than
 # building from source for reproducibility.
-RUN apt-get update && apt-get install --no-install-recommends -y \
-        autoconf \
-        automake \
-        build-essential \
-        ca-certificates \
-        git \
-        libcurl4-openssl-dev \
-        libssl-dev \
-        libtool \
-        pkg-config \
+#
+# Hotfix #18 (2026-05-14): wrap in a 3-retry loop with --fix-missing
+# fallback to absorb transient Debian mirror flakes. The original
+# unwrapped apt-get install failed CI run #N on a "Connection reset
+# by peer" mid-fetch of libssh2-1 from fastly's debian.org mirror at
+# 151.101.202.132. Mirrors flake; production-grade Dockerfiles wrap
+# network ops in retry. Same pattern as the main Dockerfile's npm-ci
+# 3-retry loop from Hotfix #9.
+RUN for i in 1 2 3; do \
+        apt-get update && \
+        apt-get install --no-install-recommends -y --fix-missing \
+            autoconf \
+            automake \
+            build-essential \
+            ca-certificates \
+            git \
+            libcurl4-openssl-dev \
+            libssl-dev \
+            libtool \
+            pkg-config \
+        && break; \
+        echo "apt-get install attempt $i/3 failed; sleeping 5s before retry"; \
+        sleep 5; \
+    done \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /src
@@ -172,13 +186,22 @@ RUN git clone --depth 1 --branch ${LIBEST_REF} https://github.com/cisco/libest.g
 # Pinned to the same digest as the builder above (Bundle A / H-001).
 FROM debian:bullseye-slim@sha256:1a4701c321b1d28b1ff5f0230e766791e4b79b1d4c6c7a70064f4b297b1a330f
 
-RUN apt-get update && apt-get install --no-install-recommends -y \
-        bash \
-        ca-certificates \
-        curl \
-        libcurl4 \
-        libssl1.1 \
-        openssl \
+# Hotfix #18 (2026-05-14): same 3-retry pattern as the builder stage
+# above. Runtime image installs are also vulnerable to transient
+# mirror flakes.
+RUN for i in 1 2 3; do \
+        apt-get update && \
+        apt-get install --no-install-recommends -y --fix-missing \
+            bash \
+            ca-certificates \
+            curl \
+            libcurl4 \
+            libssl1.1 \
+            openssl \
+        && break; \
+        echo "apt-get install attempt $i/3 failed; sleeping 5s before retry"; \
+        sleep 5; \
+    done \
     && rm -rf /var/lib/apt/lists/* \
     && useradd --create-home --uid 1000 estuser