is_server_up and wait_for_server_to_boot up functions

bin/lib/common.sh

@@ -0,0 +1,75 @@
+# common useful functions
+
+w3m_safe() {
+  url="$1"
+
+  output=$(/opt/homebrew/bin/w3m "$url" -M -cols 400 -graph -dump 2>&1)
+
+  if echo "$output" | grep -q "Can't load"; then
+    return 2
+  else
+    echo "$output"
+    return 0
+  fi
+}
+
+
+# Returns:
+#   0 = server reachable & command ran
+#   1 = network/host-not-up-yet
+#   2 = SSH auth failure (likely passphrase/key issue) -> caller should abort
+is_server_up() {
+    host=$1
+
+    # Capture only stderr (order of redirs matters: 2>&1 >/dev/null)
+    err=$(/usr/bin/ssh \
+        -o BatchMode=yes \
+        -o PreferredAuthentications=publickey \
+        -o ConnectTimeout=10 \
+        -o ServerAliveInterval=20 \
+        -o ServerAliveCountMax=3 \
+        -o ConnectionAttempts=1 \
+        -o StrictHostKeyChecking=no \
+        -o UserKnownHostsFile=/dev/null \
+        -o LogLevel=ERROR \
+        -n -q "$host" 'uname -n || hostname' 2>&1 >/dev/null)
+    st=$?
+
+    [ $st -eq 0 ] && return 0
+
+    # Normalize to lowercase for robust matching
+    err_lc=$(printf '%s' "$err" | tr '[:upper:]' '[:lower:]')
+
+    case $err_lc in
+        *"permission denied"*|\
+        *"no supported authentication methods available"*|\
+        *"too many authentication failures"*|\
+        *"agent admitted failure"*|\
+        *"publickey authentication failed"*)
+            printf 'FATAL: SSH authentication failed for "%s": %s\n' "$host" "$err" >&2
+            return 2
+            ;;
+    esac
+
+    # Anything else (timeout, connection refused, kex read/reset, etc.)
+    return 1
+}
+
+wait_for_server_to_boot_up() {
+    server=$1
+    while :; do
+        if is_server_up "$server"; then
+            printf '"%s" is up and running.\n' "$server"
+            return 0
+        fi
+        rc=$?
+        if [ $rc -eq 2 ]; then
+            printf 'Aborting: SSH authentication failed for "%s" (likely passphrase needed or wrong key).\n' "$server" >&2
+            exit 2
+        fi
+        printf 'Server "%s" is not up\n' "$server"
+        sleep 10
+    done
+}
+
+# vim: set ts=4 sw=4 tw=0 noet ft=bash: