From 9c5d8c32f70c0b8659396c39a212c1224f24d710 Mon Sep 17 00:00:00 2001 From: Claude Date: Fri, 14 Aug 2026 13:11:44 +0000 Subject: [PATCH] Reuse the sudo user's SSH key for root; make B2 rejection unambiguous MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Two separate fixes from a live report. 1. The DR-spare and SFTP-mirror sections both checked ONLY /root/.ssh for a key, missing the common case: the person running `sudo ./setup.sh backup` already has a key under their own home directory (used interactively, quite possibly already authorized on the target box), while root — who actually runs the scheduled systemd service — has none. Confirmed live: "the computer has the ssh key for the sudo user on the box" produced "No SSH key found for root" with no inline way to do anything about it beyond a pointer to go set one up elsewhere and re-run. Factored both call sites into one shared _backup_ensure_root_ssh_key() that checks root first, then offers to reuse the sudo user's existing keypair (copied into /root/.ssh with correct ownership/permissions, root:root 600) before falling back to generating a brand new one — reusing an existing key can work immediately if it's already authorized on the target, where a fresh key needs a new ssh-copy-id round-trip regardless. Verified all three branches (root already has a key, root has none but the user does and accepts reuse, neither exists and one gets generated) against a mocked filesystem. 2. The B2 dry-run failure message read like it could be about missing input even when every field was non-empty — confirmed there's no code path where non-blank-but-wrong values actually trigger the separate "Left blank" message (the two are on disjoint branches), but the dry-run failure text itself didn't rule that out or point at the actual likely cause. Now echoes back what was entered (bucket, endpoint, Key ID — never the secret) so it's easy to eyeball against B2's own confirmation screen, states plainly that this is a rejection of non-blank input, and names the most likely cause directly: pairing the Key ID from one Application Key with the Secret from a different one, which is easy to do after creating more than one while troubleshooting. Co-Authored-By: Claude Sonnet 5 Claude-Session: https://claude.ai/code/session_01H4k6J1qXXyYxhGEgnJaMvn --- services/backup.sh | 93 +++++++++++++++++++++++++++++++++++++--------- 1 file changed, 75 insertions(+), 18 deletions(-) diff --git a/services/backup.sh b/services/backup.sh index 8509147..543c778 100644 --- a/services/backup.sh +++ b/services/backup.sh @@ -207,6 +207,60 @@ fi register_service backup backup "Encrypted backup of all Docker services (full restore)" +# Ensures root has an SSH key usable for the systemd-run (root, unattended) +# backup/mirror steps. The DR-spare and SFTP-mirror prompts both need one — +# both used to check ONLY /root/.ssh, missing the common case where +# whoever ran `sudo ./setup.sh backup` already has a key under their OWN +# home directory (used interactively, quite possibly already authorized on +# the target box) while root — who actually runs the scheduled service — +# has none. Prefers reusing that existing keypair over minting a fresh +# one, since the existing one may already be trusted where it's needed; +# ssh-copy-id-ing a brand new key is the fallback, not the first move. +# Sets _ROOT_SSH_KEYFILE (out-param, not local) to the resulting keyfile +# path, empty if none is available/created. +_backup_ensure_root_ssh_key() { + _ROOT_SSH_KEYFILE="" + if [ -f /root/.ssh/id_ed25519 ]; then + _ROOT_SSH_KEYFILE=/root/.ssh/id_ed25519; return 0 + fi + if [ -f /root/.ssh/id_rsa ]; then + _ROOT_SSH_KEYFILE=/root/.ssh/id_rsa; return 0 + fi + + local _user_key="" + [ -f "$ACTUAL_HOME/.ssh/id_ed25519" ] && _user_key="$ACTUAL_HOME/.ssh/id_ed25519" + [ -z "$_user_key" ] && [ -f "$ACTUAL_HOME/.ssh/id_rsa" ] && _user_key="$ACTUAL_HOME/.ssh/id_rsa" + + if [ -n "$_user_key" ]; then + local _COPY_USER_KEY="" + prompt_yn " No SSH key for root, but $ACTUAL_USER has one ($_user_key) — reuse it for root too (it may already be authorized where you need it)? (y/n):" "y" _COPY_USER_KEY + if [[ "$_COPY_USER_KEY" =~ ^[Yy]$ ]]; then + mkdir -p /root/.ssh && chmod 700 /root/.ssh + local _keyname; _keyname="$(basename "$_user_key")" + cp "$_user_key" "/root/.ssh/$_keyname" + [ -f "${_user_key}.pub" ] && cp "${_user_key}.pub" "/root/.ssh/${_keyname}.pub" + chown root:root "/root/.ssh/$_keyname" "/root/.ssh/${_keyname}.pub" 2>/dev/null + chmod 600 "/root/.ssh/$_keyname" + [ -f "/root/.ssh/${_keyname}.pub" ] && chmod 644 "/root/.ssh/${_keyname}.pub" + log_success " Copied $_user_key to /root/.ssh/ for root's use." + _ROOT_SSH_KEYFILE="/root/.ssh/$_keyname" + return 0 + fi + fi + + local _GEN_KEY="" + prompt_yn " Generate a new SSH key for root (ssh-keygen)? (y/n):" "y" _GEN_KEY + if [[ "$_GEN_KEY" =~ ^[Yy]$ ]]; then + mkdir -p /root/.ssh && chmod 700 /root/.ssh + if ssh-keygen -t ed25519 -N "" -f /root/.ssh/id_ed25519 -q; then + log_success " Generated /root/.ssh/id_ed25519" + _ROOT_SSH_KEYFILE=/root/.ssh/id_ed25519 + else + log_warning " ssh-keygen failed — generate one manually." + fi + fi +} + install_backup() { require_docker || return 1 @@ -550,17 +604,7 @@ install_backup() { esac fi - local _HAVE_KEY=false - [ -f /root/.ssh/id_ed25519 ] || [ -f /root/.ssh/id_rsa ] && _HAVE_KEY=true - if [ "$_HAVE_KEY" = false ]; then - local _GEN_KEY="" - prompt_yn " No SSH key found for root — generate one now (ssh-keygen)? (y/n):" "y" _GEN_KEY - if [[ "$_GEN_KEY" =~ ^[Yy]$ ]]; then - ssh-keygen -t ed25519 -N "" -f /root/.ssh/id_ed25519 -q \ - && log_success " Generated /root/.ssh/id_ed25519" \ - || log_warning " ssh-keygen failed — generate one manually." - fi - fi + _backup_ensure_root_ssh_key local _COPY_KEY="" prompt_yn " Run ssh-copy-id to $DR_SYNC_HOST now? (asks for its login password interactively) (y/n):" "y" _COPY_KEY @@ -724,7 +768,23 @@ install_backup() { REMOTE_ARGS="--bucket=$B2_BUCKET --access-key=$B2_KEY_ID --secret-access-key=$B2_APP_KEY --endpoint=$B2_ENDPOINT" log_success "B2 credentials verified — offsite mirroring will run after each backup." else - log_warning "B2 dry-run failed — check bucket name, endpoint, and key permissions:" + # All four fields were non-empty (the blank-field check above + # already ruled that out) — this is B2 rejecting what was + # entered, not missing input. Echoing back what was actually + # used (never the secret) so it's easy to eyeball against + # B2's own confirmation screen — the most common cause here + # is pairing the Key ID from one Application Key with the + # Secret from a different one (e.g. after creating more than + # one while troubleshooting). + log_warning "B2 rejected these credentials — bucket, endpoint, or key mismatch" + log_warning "(not blank input — all four fields were entered):" + log_warning " Bucket: $B2_BUCKET" + log_warning " Endpoint: $B2_ENDPOINT" + log_warning " Application Key ID: $B2_KEY_ID" + log_warning "Common cause: the Key ID and Application Key are from two DIFFERENT" + log_warning "keys (easy to mix up if you created more than one). Re-check both" + log_warning "values come from the SAME entry on B2's App Keys page." + log_warning "Raw error from B2/Kopia:" log_warning "$_b2_err" log_warning "Not enabling offsite mirroring this run. Re-run this installer once" log_warning "fixed, or hand-edit REMOTE_TYPE/REMOTE_ARGS in backup.conf directly." @@ -799,14 +859,11 @@ install_backup() { # sync-to sftp doesn't shell out to the system ssh client, so it # needs an explicit key/known_hosts file rather than picking up # whatever plain `ssh` already trusts automatically. - local _SFTP_KEYFILE="" - [ -f /root/.ssh/id_ed25519 ] && _SFTP_KEYFILE=/root/.ssh/id_ed25519 - [ -z "$_SFTP_KEYFILE" ] && [ -f /root/.ssh/id_rsa ] && _SFTP_KEYFILE=/root/.ssh/id_rsa + _backup_ensure_root_ssh_key + local _SFTP_KEYFILE="$_ROOT_SSH_KEYFILE" if [ -z "$_SFTP_KEYFILE" ]; then - log_warning " No SSH key found for root — this mirror needs one. Set one up (the" - log_warning " DISASTER-RECOVERY SPARE section above offers to generate one) and" - log_warning " re-run this installer to add the mirror." + log_warning " No SSH key available for root — can't add this mirror." elif ! ssh -o BatchMode=yes -o ConnectTimeout=5 "$_SFTP_DEST" true 2>/dev/null; then log_warning " Couldn't SSH to $_SFTP_DEST without a password — not adding this" log_warning " mirror until that works: ssh-copy-id $_SFTP_DEST"