correct permissions before launch for misbehaving services

compile.ts

@@ -16,7 +16,7 @@ for (const target of targets) {
     sugoiSpawn('deno', 'compile',
         '--target', target,
         '--include', 'src/snapper-template.txt',
-        '--include', 'src/snapper@.service',
+        '--include', 'src/snapback@.service',
         '--output', 'dist/snapback-'+target,
         '--permission-set','src/main.ts'
     )

deno.json

@@ -5,7 +5,8 @@
         "permissions": {
             "read": true,
             "write": true,
-            "run": ["tar","chmod"]
+            "run": ["tar","chmod"],
+            "env": true
         }
     }
 }

src/main.ts

@@ -3,11 +3,12 @@
 import { program } from "commander"
 import { parseJSON, parseTOML, stringifyJSON } from "confbox"
 import fs from "node:fs"
+import path from "node:path"
 import strftime from 'strftime'
 import { spawnSync } from "node:child_process"
 
-let config: { [key: string]: string } = {}
-let index: { [key: string]: { [key: string]: string } } = {}
+let config: { [key: string]: string|undefined } = {}
+let index: { [key: string]: { [key: string]: string|undefined }|undefined } = {}
 
 function sugoiSpawn(...command: string[]) {
     const result = spawnSync(command.shift()!, command, { stdio: 'inherit' })
@@ -35,45 +36,57 @@ program.command('*').description('snapback ignores unknown commands')
 program.command('install').description('installs snapback on your system')
     .action(function () {
         const template = fs.readFileSync(import.meta.dirname + '/snapper-template.txt')
-        const service = fs.readFileSync(import.meta.dirname + '/snapper@.service')
+        const service = fs.readFileSync(import.meta.dirname + '/snapback@.service')
         let lib_snapper = '/usr/libexec/snapper'
         if (!fs.existsSync(lib_snapper)) lib_snapper = '/usr/lib/snapper'
         if (!fs.existsSync('/etc/snapper/config-templates')) fs.mkdirSync('/etc/snapper/config-templates')
         fs.writeFileSync('/etc/snapper/config-templates/snapback', template, 'utf8')
-        fs.writeFileSync('/etc/systemd/system/snapper@.service', service, 'utf8')
+        fs.writeFileSync('/etc/systemd/system/snapback@.service', service, 'utf8')
         fs.mkdirSync(lib_snapper + '/plugins', { recursive: true })
-        fs.renameSync(import.meta.url, lib_snapper + '/plugins/99-snapback')
+        let argv0 = process.argv0
+        if (['node','deno','bun'].includes(path.basename(argv0).replace('.exe',''))) {
+            argv0 = import.meta.url
+        }
+        fs.renameSync(argv0, lib_snapper + '/plugins/99-snapback')
         sugoiSpawn('chmod', '+x', lib_snapper + '/plugins/99-snapback')
+        sugoiSpawn('systemctl','daemon-reload')
         console.log('snapback installed')
     })
 
 program.command('create-snapshot-post <subvolume> <fstype> <number>')
     .description('create a backup after a snapshot')
     .action(function (subvolume, fstype, number) {
-        if (!config[subvolume]) return
+        if (!config[subvolume]) {console.log(subvolume + ' not configured for snapback'); return}
         const destination = strftime(config[subvolume])
+        const dirname = path.dirname(destination)
+        try { fs.mkdirSync(dirname, { 'recursive': true }) } catch {}
         sugoiSpawn('tar',
             `--directory=${subvolume}/.snapshots/${number}/snapshot`,
             '--create', '--file', destination,
             '--auto-compress', '--dereference', '.'
         )
+        if(!index[subvolume]) index[subvolume]={}
         index[subvolume][number] = destination
+        console.log('created backup at '+destination)
     })
 
 program.command('delete-snapshot-post <subvolume> <fstype> <number>')
     .description('delete a backup after deleting a snapshot')
     .action(function (subvolume, fstype, number) {
+        if (!index[subvolume]) {
+            console.log('no backups indexed for ' + subvolume)
+            return
+        }
         const destination = index[subvolume][number]
+        if (!destination) {
+            console.log('no backup indexed for ' + subvolume + ':' + number)
+            return
+        }
         fs.unlinkSync(destination)
         delete index[subvolume][number]
-    })
-
-program.command('delete-config-post <subvolume> <fstype>')
-    .description('delete metadata of deleted subvolume, retaining backups')
-    .action(function (subvolume, fstype) {
-        delete index[subvolume]
+        console.log('deleted backup at '+destination)
     })
 
 program.parse()
 
-if (Object.keys(index).length) fs.writeFileSync(program.opts().indexFile,stringifyJSON(index), 'utf8')
+fs.writeFileSync(program.opts().indexFile,stringifyJSON(index), 'utf8')

src/snapback@.service

@@ -0,0 +1,6 @@
+[Service]
+Type=exec
+ExecStartPre=-btrfs subvolume create %I
+ExecStartPre=-snapper --no-dbus --config %i create-config --template snapback %I
+ExecStartPre=chown 0 %I/.snapshots
+ExecStart=snapper --no-dbus --config %i create --cleanup-algorithm number

src/snapper@.service

@@ -1,5 +0,0 @@
-[Service]
-Type=exec
-ExecStartPre=-btrfs subvolume create %I
-ExecStartPre=-snapper --config %i create-config %I --template snapback
-ExecStart=snapper --config %i create --cleanup-algorithm number