[pbs-devel] [PATCH proxmox-backup 3/3] add restore of index files

[Hannes Laimer <h.laimer@proxmox.com>]

Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
---
Adds possibility to restore data from an index file. Options:
 - chunks: path to the directory where the chunks are saved
 - file: the index file that should be restored(must be either .fidx or
   didx)
 - [opt] keyfile: path to a keyfile, if the data was encrypted, a keyfile is
   needed
 - [opt] skip-crc: boolean, if true, read chunks wont be verified with their
   crc-sum, increases the restore speed by a lot

 src/bin/proxmox-backup-recovery.rs | 109 ++++++++++++++++++++++++++++-
 1 file changed, 107 insertions(+), 2 deletions(-)

diff --git a/src/bin/proxmox-backup-recovery.rs b/src/bin/proxmox-backup-recovery.rs
index ae8c18d5..c2b9fdfa 100644
--- a/src/bin/proxmox-backup-recovery.rs
+++ b/src/bin/proxmox-backup-recovery.rs
@@ -1,9 +1,21 @@
+use std::fs::File;
+use std::io::{Read, Write};
+use std::path::Path;
+
 use anyhow::Error;
 use proxmox::api::schema::{Schema, StringSchema};
-use proxmox::api::cli::*;
+use proxmox::api::{api, cli::*};
+use proxmox::tools::digest_to_hex;
+use serde_json::Value;
 
 use proxmox::sys::linux::tty;
+use proxmox_backup::backup::{
+    load_and_decrypt_key, CryptConfig, DataBlob, DynamicIndexReader, FixedIndexReader, IndexFile,
+};
+use proxmox_backup::tools;
 use proxmox_backup_recovery::*;
+use std::time::Instant;
+
 mod proxmox_backup_recovery;
 
 pub fn get_encryption_key_password() -> Result<Vec<u8>, Error> {
@@ -17,11 +29,104 @@ pub const KEYFILE_SCHEMA: Schema = StringSchema::new(
 )
 .schema();
 
+#[api(
+    input: {
+        properties: {
+            file: {
+                schema: PATH_SCHEMA,
+            },
+            chunks: {
+                schema: PATH_SCHEMA,
+            },
+            "keyfile": {
+                schema: KEYFILE_SCHEMA,
+                optional: true,
+            },
+            "skip-crc": {
+                type: Boolean,
+                optional: true,
+                default: false,
+                description: "Skip the crc verification, increases the restore speed immensely",
+            }
+        }
+    }
+)]
+/// Restore a index file
+fn restore(skip_crc: bool, param: Value) -> Result<Value, Error> {
+    let start = Instant::now();
+    let file_path = Path::new(tools::required_string_param(&param, "file")?);
+    let chunks_path = Path::new(tools::required_string_param(&param, "chunks")?);
+
+    let key_file_param = param["keyfile"].as_str();
+    let mut key_file_path = None;
+
+    if let Some(path) = key_file_param {
+        key_file_path = Some(Path::new(path))
+    };
+
+    let file_name = file_path.file_name().unwrap().to_str().unwrap();
+    let mut index: Option<Box<dyn IndexFile>> = None;
+
+    if file_name.ends_with(".fidx") {
+        index = match FixedIndexReader::open(file_path) {
+            Ok(index) => Some(Box::new(index)),
+            Err(_) => None,
+        };
+    }
+
+    if file_name.ends_with(".didx") {
+        index = match DynamicIndexReader::open(file_path) {
+            Ok(index) => Some(Box::new(index)),
+            Err(_) => None,
+        };
+    }
+
+    let mut crypt_conf_opt = None;
+    let mut crypt_conf;
+
+    let output_filename = &file_name[0..file_name.len() - 5];
+    let output_path = Path::new(output_filename);
+    let mut output_file = File::create(output_path)?;
+    if let Some(index) = index {
+        for pos in 0..index.index_count() {
+            let chunk_digest = index.index_digest(pos).unwrap();
+            let digest_str = digest_to_hex(chunk_digest);
+            let digest_prefix = &digest_str[0..4];
+            let chunk_path = chunks_path.join(digest_prefix).join(digest_str);
+            let mut chunk_file = std::fs::File::open(&chunk_path)?;
+
+            let mut data = Vec::with_capacity(1024 * 1024);
+            chunk_file.read_to_end(&mut data)?;
+            let chunk_blob = DataBlob::from_raw(data)?;
+
+            if !skip_crc {
+                chunk_blob.verify_crc()?;
+            }
+
+            if key_file_path.is_some() && chunk_blob.is_encrypted() && crypt_conf_opt.is_none() {
+                let (key, _created, _fingerprint) =
+                    load_and_decrypt_key(&key_file_path.unwrap(), &get_encryption_key_password)?;
+                crypt_conf = CryptConfig::new(key)?;
+                crypt_conf_opt = Some(&crypt_conf);
+            }
+
+            output_file.write_all(
+                chunk_blob
+                    .decode(crypt_conf_opt, Some(chunk_digest))?
+                    .as_slice(),
+            )?;
+        }
+    }
+    println!("{} sec.", start.elapsed().as_secs_f32());
+    Ok(Value::Null)
+}
+
 fn main() {
     proxmox_backup::tools::setup_safe_path_env();
 
     let cmd_def = CliCommandMap::new()
-        .insert("inspect", inspect_commands());
+        .insert("inspect", inspect_commands())
+        .insert("restore", CliCommand::new(&API_METHOD_RESTORE));
 
     let rpcenv = CliEnvironment::new();
     run_cli_command(
-- 
2.20.1