chore: retry fetch dashboard assets (#3394)

Signed-off-by: tison <wander4096@gmail.com>

scripts/fetch-dashboard-assets.sh

@@ -1,8 +1,7 @@
 #!/usr/bin/env bash
 
 # This script is used to download built dashboard assets from the "GreptimeTeam/dashboard" repository.
-
-set -e -x
+set -ex
 
 declare -r SCRIPT_DIR=$(cd $(dirname ${0}) >/dev/null 2>&1 && pwd)
 declare -r ROOT_DIR=$(dirname ${SCRIPT_DIR})
@@ -20,13 +19,32 @@ else
   GITHUB_URL="${GITHUB_PROXY_URL%/}"
 fi
 
+function retry_fetch() {
+    local url=$1
+    local filename=$2
+
+    curl \
+      --connect-timeout 10 \
+      --retry 3 \
+      --retry-connrefused \
+      -fsSL $url --output $filename || \
+      {
+        echo "Failed to download $url"
+        echo "You may try to set http_proxy and https_proxy environment variables."
+        if [[ -z "$GITHUB_PROXY_URL" ]]; then
+          echo "You may try to set GITHUB_PROXY_URL=http://mirror.ghproxy.com/"
+        fi
+        exit 1
+     }
+}
+
 # Download the SHA256 checksum attached to the release. To verify the integrity
 # of the download, this checksum will be used to check the download tar file
 # containing the built dashboard assets.
-curl -Ls ${GITHUB_URL}/GreptimeTeam/dashboard/releases/download/$RELEASE_VERSION/sha256.txt --output sha256.txt
+retry_fetch "${GITHUB_URL}/GreptimeTeam/dashboard/releases/download/${RELEASE_VERSION}/sha256.txt" sha256.txt
 
 # Download the tar file containing the built dashboard assets.
-curl -L ${GITHUB_URL}/GreptimeTeam/dashboard/releases/download/$RELEASE_VERSION/build.tar.gz --output build.tar.gz
+retry_fetch "${GITHUB_URL}/GreptimeTeam/dashboard/releases/download/$RELEASE_VERSION/build.tar.gz" build.tar.gz
 
 # Verify the checksums match; exit if they don't.
 case "$(uname -s)" in