borg: add ARM binary for Pi; update scripts to use it

Makefile

@@ -38,7 +38,7 @@ rebase:
 	git pull
 	git checkout -
 	git rebase master
-	./initial-setup.sh --update-paths
+	./initial-setup.sh --update
 	systemctl daemon-reload
 	git status
 

README.md

@@ -77,7 +77,7 @@ This doesn't require the repo key.  It shouldn't be entered on the untrusted
 backup host, so for operations that need it, use a trusted host and run borg
 remotely instead, e.g.:
 
-    ${BORG_DIR}/Borg.bin --remote-path borg/borg info ${BACKUP_USER}@${BACKUP_HOST}:borg/${HOSTNAME}
+    ${BORG_DIR}/bin/borg --remote-path borg/borg info ${BACKUP_USER}@${BACKUP_HOST}:borg/${HOSTNAME}
 
 The repo passphrase is in bitwarden `borg ${HOSTNAME} / repo key`.
 
@@ -115,11 +115,12 @@ Design
 Notes
 =====
 
-# Building Borg.bin binary from git
+# Building Borg binary from git
 
+    sudo apt install python3.9 scons libacl1-dev libfuse-dev libpython3.9-dev patchelf
     git clone https://github.com/borgbackup/borg.git
     cd borg
-    virtualenv --python=python3 borg-env
+    virtualenv --python=python3.9 borg-env
     source borg-env/bin/activate
     pip install -r requirements.d/development.txt
     pip install pyinstaller
@@ -127,9 +128,14 @@ Notes
     pip install -e .[llfuse]
     pyinstaller --clean --noconfirm scripts/borg.exe.spec
     pip install staticx
-    staticx -l /lib/x86_64-linux-gnu/libm.so.6 dist/borg.exe Borg.bin
 
-Then see `dist/borg.exe`.  Confirm the version with `dist/borg.exe --version`.
+    # for x86
+    staticx -l /lib/x86_64-linux-gnu/libm.so.6 dist/borg.exe borg.x86_64
+
+    # for ARM; see https://github.com/JonathonReinhart/staticx/issues/209
+    staticx -l /lib/arm-linux-gnueabihf/libm.so.6 dist/borg.exe borg.armv7l
+
+Then run `borg.x86_64`.  Confirm the version with `borg.armv7l --version`.
 
 *Note:* This uses the deprecated `llfuse` instead of the newer `pyfuse3`.
 `pyfuse3` doesn't work because, at minimum, it pulls in `trio` which

initial-setup.sh

@@ -10,9 +10,7 @@ BACKUP_REPO=${BACKUP_REPO:-borg/${HOSTNAME}}
 BORG_DIR="$(realpath "$(dirname "$0")")"
 cd "${BORG_DIR}"
 
-# This is named with uppercase so that it doesn't tab-complete for
-# "./b<tab>", which should give us "./borg.sh"
-BORG_BIN="${BORG_DIR}/Borg.bin"
+BORG_BIN="${BORG_DIR}/bin/borg.$(uname -m)"
 
 # Use stable host ID in case MAC address changes
 HOSTID="${HOSTNAME}@$(python -c 'import uuid;print(uuid.getnode())')"
@@ -27,6 +25,46 @@ trap 'error_handler ${BASH_SOURCE} ${LINENO} $?' ERR
 set -o errexit
 set -o errtrace
 
+# Create pip environment
+setup_venv()
+{
+    if ! which pipenv >/dev/null 2>&1 ; then
+        echo "pipenv not found, try: sudo apt install pipenv"
+        exit 1
+    fi
+    mkdir -p .venv
+    pipenv install
+}
+
+# Create shell script with environment variables
+create_borg_vars()
+{
+    VARS=${BORG_DIR}/vars.sh
+
+    # These variables are used elsewhere in this script
+    BORG_REPO="ssh://${BACKUP_USER}@${BACKUP_HOST}/./${BACKUP_REPO}"
+    BORG=${BORG_DIR}/borg.sh
+    SSH=$BORG_DIR/ssh
+
+    cat >"$VARS" <<EOF
+export BACKUP_USER=${BACKUP_USER}
+export BACKUP_HOST=${BACKUP_HOST}
+export BACKUP_REPO=${BACKUP_REPO}
+export HOSTNAME=${HOSTNAME}
+export BORG_REPO=${BORG_REPO}
+export BORG_HOST_ID=${HOSTID}
+export BORG_PASSCOMMAND="cat ${BORG_DIR}/passphrase"
+export BORG_DIR=${BORG_DIR}
+export SSH=${SSH}
+export BORG=${BORG}
+export BORG_BIN=${BORG_BIN}
+EOF
+    if ! "$BORG" -h >/dev/null ; then
+        error "Can't run the borg wrapper; does borg work?"
+    fi
+}
+
+# Update paths in README and backup.py
 update_paths()
 {
     sed -i \
@@ -42,13 +80,16 @@ update_paths()
         backup.py
 }
 
-if [ "$1" == "--update-paths" ] ; then
+# See if we're just supposed to update an existing install
+if [ "$1" == "--update-paths" ] || [ "$1" == "--update" ] ; then
     if [ -e "vars.sh" ]; then
-        echo "Updating paths"
+        echo "Updating paths and variables"
         update_paths
+        setup_venv
+        update_vars
         exit 0
     else
-        echo "Can't update paths, not set up yet"
+        echo "Can't update, not set up yet"
         exit 1
     fi
 fi
@@ -92,46 +133,6 @@ notice() { msg 32 "$@" ; }
 warn() { msg 31 "$@" ; }
 error() { msg 31 "Error:" "$@" ; exit 1 ; }
 
-# Create pip environment
-setup_venv()
-{
-    if ! which pipenv >/dev/null 2>&1 ; then
-        echo "pipenv not found, try: sudo apt install pipenv"
-        exit 1
-    fi
-    mkdir .venv
-    pipenv install
-}
-
-# Create shell script with environment variables
-create_borg_vars()
-{
-    VARS=${BORG_DIR}/vars.sh
-
-    # These variables are used elsewhere in this script
-    BORG_REPO="ssh://${BACKUP_USER}@${BACKUP_HOST}/./${BACKUP_REPO}"
-    BORG=${BORG_DIR}/borg.sh
-    SSH=$BORG_DIR/ssh
-
-    cat >"$VARS" <<EOF
-export BACKUP_USER=${BACKUP_USER}
-export BACKUP_HOST=${BACKUP_HOST}
-export BACKUP_REPO=${BACKUP_REPO}
-export HOSTNAME=${HOSTNAME}
-export BORG_REPO=${BORG_REPO}
-export BORG_HOST_ID=${HOSTID}
-export BORG_PASSCOMMAND="cat ${BORG_DIR}/passphrase"
-export BORG_DIR=${BORG_DIR}
-export SSH=${SSH}
-export BORG=${BORG}
-export BORG_BIN=${BORG_BIN}
-EOF
-    if ! "$BORG" -h >/dev/null ; then
-        error "Can't run the borg wrapper; does borg work?"
-    fi
-
-}
-
 print_random_key()
 {
     dd if=/dev/urandom | tr -dc 'a-zA-Z0-9' | head -c 16