fix(ci): retry the Stellar CLI download to survive CDN 503s (#119)

.github/workflows/ci.yml

@@ -40,7 +40,7 @@ jobs:
 
       - name: Install Stellar CLI
         if: steps.stellar-cli-cache.outputs.cache-hit != 'true'
-        uses: stellar/stellar-cli@v27.0.0
+        run: bash scripts/install-stellar-cli.sh 27.0.0
 
       # The install action puts ~/.local/bin on PATH itself; on a cache hit it is
       # skipped, so add the directory here too.
@@ -106,9 +106,7 @@ jobs:
 
       - name: Install Stellar CLI ${{ matrix.stellar-version }}
         if: steps.stellar-cli-cache.outputs.cache-hit != 'true'
-        uses: stellar/stellar-cli@v27.0.0
-        with:
-          version: ${{ matrix.stellar-version }}
+        run: bash scripts/install-stellar-cli.sh ${{ matrix.stellar-version }}
 
       - name: Add Stellar CLI to PATH
         run: echo "$HOME/.local/bin" >> "$GITHUB_PATH"

.github/workflows/testnet-deploy-regression.yml

@@ -41,7 +41,7 @@ jobs:
 
       - name: Install Stellar CLI
         if: steps.stellar-cli-cache.outputs.cache-hit != 'true'
-        uses: stellar/stellar-cli@v27.0.0
+        run: bash scripts/install-stellar-cli.sh 27.0.0
 
       # The install action puts ~/.local/bin on PATH itself; on a cache hit it is
       # skipped, so add the directory here too.

.github/workflows/testnet-smoke.yml

@@ -45,7 +45,7 @@ jobs:
 
       - name: Install Stellar CLI
         if: steps.stellar-cli-cache.outputs.cache-hit != 'true'
-        uses: stellar/stellar-cli@v27.0.0
+        run: bash scripts/install-stellar-cli.sh 27.0.0
 
       # The install action puts ~/.local/bin on PATH itself; on a cache hit it is
       # skipped, so add the directory here too.

scripts/install-stellar-cli.sh

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+# Install the Stellar CLI release binary with a resilient download.
+#
+# The official `stellar/stellar-cli` action only retries the CDN download a
+# handful of times over ~25s, which a multi-minute 503 outage from the GitHub
+# releases CDN can still blow past (see issue #119). When the binary is not
+# already restored from `actions/cache`, this helper performs the same
+# download with an exponential backoff that rides out much longer outages.
+#
+# Usage: install-stellar-cli.sh <version> [os-arch-triple]
+#   version           CLI version, with or without a leading "v" (e.g. 27.0.0)
+#   os-arch-triple    target triple (default: x86_64-unknown-linux-gnu)
+set -euo pipefail
+
+version_raw="${1:?Usage: install-stellar-cli.sh <version> [os-arch-triple]}"
+os_arch="${2:-x86_64-unknown-linux-gnu}"
+
+version="${version_raw#v}"
+install_dir="$HOME/.local/bin"
+mkdir -p "$install_dir"
+
+file="stellar-cli-${version}-${os_arch}.tar.gz"
+url="https://github.com/stellar/stellar-cli/releases/download/v${version}/${file}"
+
+temp_dir="$(mktemp -d)"
+trap 'rm -rf "$temp_dir"' EXIT
+
+archive_path="${temp_dir}/${file}"
+
+# Exponential backoff: 10s, 20s, 40s, 80s, 160s => ~5min of retries.
+max_attempts=6
+delay=10
+
+attempt=1
+until curl -fSL --retry 0 "$url" -o "$archive_path"; do
+  if (( attempt >= max_attempts )); then
+    echo "error: failed to download ${url} after ${max_attempts} attempts" >&2
+    exit 1
+  fi
+  echo "warning: download of ${url} failed (attempt ${attempt}); retrying in ${delay}s" >&2
+  sleep "$delay"
+  delay=$(( delay * 2 ))
+  attempt=$(( attempt + 1 ))
+done
+
+tar xzf "$archive_path" -C "$install_dir"
+chmod +x "${install_dir}/stellar"
+
+binary="${install_dir}/stellar"
+"${binary}" --version