[pbs-devel] [PATCH proxmox-backup 2/2] add helpers to write configuration files

[Dietmar Maurer <dietmar@proxmox.com>]

---
 src/backup/mod.rs                  | 41 ++++++++++++++++++++++++++++++
 src/config/acl.rs                  | 14 +---------
 src/config/acme/plugin.rs          | 16 +-----------
 src/config/datastore.rs            | 19 +-------------
 src/config/domains.rs              | 19 +-------------
 src/config/drive.rs                | 18 +------------
 src/config/media_pool.rs           | 19 +-------------
 src/config/mod.rs                  | 10 ++------
 src/config/node.rs                 | 10 +-------
 src/config/remote.rs               | 16 +-----------
 src/config/sync.rs                 | 16 +-----------
 src/config/tape_encryption_keys.rs | 33 +++---------------------
 src/config/tape_job.rs             | 16 +-----------
 src/config/user.rs                 | 14 +---------
 src/config/verify.rs               | 17 +------------
 15 files changed, 58 insertions(+), 220 deletions(-)

diff --git a/src/backup/mod.rs b/src/backup/mod.rs
index 1db61cf5..3337f3a6 100644
--- a/src/backup/mod.rs
+++ b/src/backup/mod.rs
@@ -134,3 +134,44 @@ pub fn open_backup_lockfile<P: AsRef<std::path::Path>>(
     let file = proxmox::tools::fs::open_file_locked(&path, timeout, exclusive, options)?;
     Ok(BackupLockGuard(file))
 }
+
+/// Atomically write data to file owned by "root:backup" with permission "0640"
+///
+/// Only the superuser can write those files, but group 'backup' can read them.
+pub fn replace_backup_config<P: AsRef<std::path::Path>>(
+    path: P,
+    data: &[u8],
+) -> Result<(), Error> {
+    let backup_user = backup_user()?;
+    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
+    // set the correct owner/group/permissions while saving file
+    // owner(rw) = root, group(r)= backup
+    let options = proxmox::tools::fs::CreateOptions::new()
+        .perm(mode)
+        .owner(nix::unistd::ROOT)
+        .group(backup_user.gid);
+
+    proxmox::tools::fs::replace_file(path, data, options)?;
+
+    Ok(())
+}
+
+/// Atomically write data to file owned by "root:root" with permission "0600"
+///
+/// Only the superuser can read and write those files.
+pub fn replace_secret_config<P: AsRef<std::path::Path>>(
+    path: P,
+    data: &[u8],
+) -> Result<(), Error> {
+    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0600);
+    // set the correct owner/group/permissions while saving file
+    // owner(rw) = root, group(r)= root
+    let options = proxmox::tools::fs::CreateOptions::new()
+        .perm(mode)
+        .owner(nix::unistd::ROOT)
+        .group(nix::unistd::Gid::from_raw(0));
+
+    proxmox::tools::fs::replace_file(path, data, options)?;
+
+    Ok(())
+}
diff --git a/src/config/acl.rs b/src/config/acl.rs
index b4b3510f..b7badb79 100644
--- a/src/config/acl.rs
+++ b/src/config/acl.rs
@@ -13,7 +13,6 @@ use serde::de::{value, IntoDeserializer};
 
 use proxmox::api::{api, schema::*};
 use proxmox::constnamedbitmap;
-use proxmox::tools::{fs::replace_file, fs::CreateOptions};
 
 use crate::api2::types::{Authid, Userid};
 
@@ -912,18 +911,7 @@ pub fn save_config(acl: &AclTree) -> Result<(), Error> {
 
     acl.write_config(&mut raw)?;
 
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(ACL_CFG_FILENAME, &raw, options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(ACL_CFG_FILENAME, &raw)
 }
 
 #[cfg(test)]
diff --git a/src/config/acme/plugin.rs b/src/config/acme/plugin.rs
index fde800e2..a4322fdd 100644
--- a/src/config/acme/plugin.rs
+++ b/src/config/acme/plugin.rs
@@ -9,8 +9,6 @@ use proxmox::api::{
     section_config::{SectionConfig, SectionConfigData, SectionConfigPlugin},
 };
 
-use proxmox::tools::{fs::replace_file, fs::CreateOptions};
-
 use crate::api2::types::PROXMOX_SAFE_ID_FORMAT;
 use crate::backup::{open_backup_lockfile, BackupLockGuard};
 
@@ -168,19 +166,7 @@ pub fn config() -> Result<(PluginData, [u8; 32]), Error> {
 pub fn save_config(config: &PluginData) -> Result<(), Error> {
     super::make_acme_dir()?;
     let raw = CONFIG.write(ACME_PLUGIN_CFG_FILENAME, &config.data)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(ACME_PLUGIN_CFG_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(ACME_PLUGIN_CFG_FILENAME, raw.as_bytes())
 }
 
 pub struct PluginData {
diff --git a/src/config/datastore.rs b/src/config/datastore.rs
index 9e37073d..46d28feb 100644
--- a/src/config/datastore.rs
+++ b/src/config/datastore.rs
@@ -13,11 +13,6 @@ use proxmox::api::{
     }
 };
 
-use proxmox::tools::fs::{
-    replace_file,
-    CreateOptions,
-};
-
 use crate::api2::types::*;
 use crate::backup::{open_backup_lockfile, BackupLockGuard};
 
@@ -154,19 +149,7 @@ pub fn config() -> Result<(SectionConfigData, [u8;32]), Error> {
 
 pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(DATASTORE_CFG_FILENAME, &config)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(DATASTORE_CFG_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(DATASTORE_CFG_FILENAME, raw.as_bytes())
 }
 
 // shell completion helper
diff --git a/src/config/domains.rs b/src/config/domains.rs
index 9f513a44..0d695777 100644
--- a/src/config/domains.rs
+++ b/src/config/domains.rs
@@ -13,11 +13,6 @@ use proxmox::api::{
     }
 };
 
-use proxmox::tools::fs::{
-    replace_file,
-    CreateOptions,
-};
-
 use crate::api2::types::*;
 use crate::backup::{open_backup_lockfile, BackupLockGuard};
 
@@ -126,19 +121,7 @@ pub fn config() -> Result<(SectionConfigData, [u8;32]), Error> {
 
 pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(DOMAINS_CFG_FILENAME, &config)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(DOMAINS_CFG_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(DOMAINS_CFG_FILENAME, raw.as_bytes())
 }
 
 // shell completion helper
diff --git a/src/config/drive.rs b/src/config/drive.rs
index 9c20051f..f86582ac 100644
--- a/src/config/drive.rs
+++ b/src/config/drive.rs
@@ -25,10 +25,6 @@ use proxmox::{
             SectionConfigPlugin,
         },
     },
-    tools::fs::{
-        replace_file,
-        CreateOptions,
-    },
 };
 
 use crate::{
@@ -97,19 +93,7 @@ pub fn config() -> Result<(SectionConfigData, [u8;32]), Error> {
 /// Save the configuration file
 pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(DRIVE_CFG_FILENAME, &config)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(DRIVE_CFG_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(DRIVE_CFG_FILENAME, raw.as_bytes())
 }
 
 /// Check if the specified drive name exists in the config.
diff --git a/src/config/media_pool.rs b/src/config/media_pool.rs
index e50992d8..d9828e0f 100644
--- a/src/config/media_pool.rs
+++ b/src/config/media_pool.rs
@@ -20,10 +20,6 @@ use proxmox::{
             SectionConfigPlugin,
         }
     },
-    tools::fs::{
-        replace_file,
-        CreateOptions,
-    },
 };
 
 use crate::{
@@ -57,7 +53,6 @@ pub const MEDIA_POOL_CFG_FILENAME: &str = "/etc/proxmox-backup/media-pool.cfg";
 /// Lock file name (used to prevent concurrent access)
 pub const MEDIA_POOL_CFG_LOCKFILE: &str = "/etc/proxmox-backup/.media-pool.lck";
 
-
 /// Get exclusive lock
 pub fn lock() -> Result<BackupLockGuard, Error> {
     open_backup_lockfile(MEDIA_POOL_CFG_LOCKFILE, None, true)
@@ -77,19 +72,7 @@ pub fn config() -> Result<(SectionConfigData, [u8;32]), Error> {
 /// Save the configuration file
 pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(MEDIA_POOL_CFG_FILENAME, &config)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(MEDIA_POOL_CFG_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(MEDIA_POOL_CFG_FILENAME, raw.as_bytes())
 }
 
 // shell completion helper
diff --git a/src/config/mod.rs b/src/config/mod.rs
index 014d184f..d820ee37 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -10,7 +10,6 @@ use openssl::rsa::{Rsa};
 use openssl::x509::{X509Builder};
 use openssl::pkey::PKey;
 
-use proxmox::tools::fs::{CreateOptions, replace_file};
 use proxmox::try_block;
 
 use pbs_buildcfg::{self, configdir};
@@ -194,18 +193,13 @@ pub fn update_self_signed_cert(force: bool) -> Result<(), Error> {
 }
 
 pub(crate) fn set_proxy_certificate(cert_pem: &[u8], key_pem: &[u8]) -> Result<(), Error> {
-    let backup_user = crate::backup::backup_user()?;
-    let options = CreateOptions::new()
-        .perm(Mode::from_bits_truncate(0o0640))
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
     let key_path = PathBuf::from(configdir!("/proxy.key"));
     let cert_path = PathBuf::from(configdir!("/proxy.pem"));
 
     create_configdir()?;
-    replace_file(&key_path, &key_pem, options.clone())
+    crate::backup::replace_backup_config(&key_path, key_pem)
         .map_err(|err| format_err!("error writing certificate private key - {}", err))?;
-    replace_file(&cert_path, &cert_pem, options)
+    crate::backup::replace_backup_config(&cert_path, &cert_pem)
         .map_err(|err| format_err!("error writing certificate file - {}", err))?;
 
     Ok(())
diff --git a/src/config/node.rs b/src/config/node.rs
index dc3eeeb0..0c1c9938 100644
--- a/src/config/node.rs
+++ b/src/config/node.rs
@@ -6,7 +6,6 @@ use serde::{Deserialize, Serialize};
 
 use proxmox::api::api;
 use proxmox::api::schema::{ApiStringFormat, Updater};
-use proxmox::tools::fs::{replace_file, CreateOptions};
 
 use proxmox_http::ProxyConfig;
 
@@ -41,14 +40,7 @@ pub fn save_config(config: &NodeConfig) -> Result<(), Error> {
     config.validate()?;
 
     let raw = crate::tools::config::to_bytes(config, &NodeConfig::API_SCHEMA)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let options = CreateOptions::new()
-        .perm(Mode::from_bits_truncate(0o0640))
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(CONF_FILE, &raw, options)
+    crate::backup::replace_backup_config(CONF_FILE, &raw)
 }
 
 #[api(
diff --git a/src/config/remote.rs b/src/config/remote.rs
index 0ef70677..86fe7b6e 100644
--- a/src/config/remote.rs
+++ b/src/config/remote.rs
@@ -13,8 +13,6 @@ use proxmox::api::{
     }
 };
 
-use proxmox::tools::{fs::replace_file, fs::CreateOptions};
-
 use crate::api2::types::*;
 
 lazy_static! {
@@ -102,19 +100,7 @@ pub fn config() -> Result<(SectionConfigData, [u8;32]), Error> {
 
 pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(REMOTE_CFG_FILENAME, &config)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(REMOTE_CFG_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(REMOTE_CFG_FILENAME, raw.as_bytes())
 }
 
 // shell completion helper
diff --git a/src/config/sync.rs b/src/config/sync.rs
index 2fd3a2c1..5d5b2060 100644
--- a/src/config/sync.rs
+++ b/src/config/sync.rs
@@ -13,8 +13,6 @@ use proxmox::api::{
     }
 };
 
-use proxmox::tools::{fs::replace_file, fs::CreateOptions};
-
 use crate::api2::types::*;
 
 lazy_static! {
@@ -120,19 +118,7 @@ pub fn config() -> Result<(SectionConfigData, [u8;32]), Error> {
 
 pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(SYNC_CFG_FILENAME, &config)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(SYNC_CFG_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(SYNC_CFG_FILENAME, raw.as_bytes())
 }
 
 // shell completion helper
diff --git a/src/config/tape_encryption_keys.rs b/src/config/tape_encryption_keys.rs
index 5ee0ac1f..6d4e91b9 100644
--- a/src/config/tape_encryption_keys.rs
+++ b/src/config/tape_encryption_keys.rs
@@ -15,11 +15,7 @@ use std::collections::HashMap;
 use anyhow::{bail, Error};
 use serde::{Deserialize, Serialize};
 
-use proxmox::tools::fs::{
-    file_read_optional_string,
-    replace_file,
-    CreateOptions,
-};
+use proxmox::tools::fs::file_read_optional_string;
 
 use crate::{
     backup::{
@@ -143,18 +139,7 @@ pub fn save_keys(map: HashMap<Fingerprint, EncryptionKeyInfo>) -> Result<(), Err
     }
 
     let raw = serde_json::to_string_pretty(&list)?;
-
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0600);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= root
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(nix::unistd::Gid::from_raw(0));
-
-    replace_file(TAPE_KEYS_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_secret_config(TAPE_KEYS_FILENAME, raw.as_bytes())
 }
 
 /// Store tape encryption key configurations (password protected keys)
@@ -167,19 +152,7 @@ pub fn save_key_configs(map: HashMap<Fingerprint, KeyConfig>) -> Result<(), Erro
     }
 
     let raw = serde_json::to_string_pretty(&list)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(TAPE_KEY_CONFIG_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(TAPE_KEY_CONFIG_FILENAME, raw.as_bytes())
 }
 
 /// Insert a new key
diff --git a/src/config/tape_job.rs b/src/config/tape_job.rs
index a5901e86..f09200fc 100644
--- a/src/config/tape_job.rs
+++ b/src/config/tape_job.rs
@@ -13,8 +13,6 @@ use proxmox::api::{
     }
 };
 
-use proxmox::tools::{fs::replace_file, fs::CreateOptions};
-
 use crate::api2::types::{
     Userid,
     JOB_ID_SCHEMA,
@@ -159,19 +157,7 @@ pub fn config() -> Result<(SectionConfigData, [u8;32]), Error> {
 
 pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(TAPE_JOB_CFG_FILENAME, &config)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(TAPE_JOB_CFG_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(TAPE_JOB_CFG_FILENAME, raw.as_bytes())
 }
 
 // shell completion helper
diff --git a/src/config/user.rs b/src/config/user.rs
index bdec5fc1..8d367ade 100644
--- a/src/config/user.rs
+++ b/src/config/user.rs
@@ -15,8 +15,6 @@ use proxmox::api::{
     }
 };
 
-use proxmox::tools::{fs::replace_file, fs::CreateOptions};
-
 use crate::api2::types::*;
 use crate::tools::Memcom;
 
@@ -259,17 +257,7 @@ pub fn cached_config() -> Result<Arc<SectionConfigData>, Error> {
 
 pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(USER_CFG_FILENAME, &config)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(USER_CFG_FILENAME, raw.as_bytes(), options)?;
+    crate::backup::replace_backup_config(USER_CFG_FILENAME, raw.as_bytes())?;
 
     // increase user cache generation
     // We use this in CachedUserInfo
diff --git a/src/config/verify.rs b/src/config/verify.rs
index 549f9801..9001fffc 100644
--- a/src/config/verify.rs
+++ b/src/config/verify.rs
@@ -13,8 +13,6 @@ use proxmox::api::{
     }
 };
 
-use proxmox::tools::{fs::replace_file, fs::CreateOptions};
-
 use crate::api2::types::*;
 
 lazy_static! {
@@ -118,20 +116,7 @@ pub fn config() -> Result<(SectionConfigData, [u8;32]), Error> {
 
 pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(VERIFICATION_CFG_FILENAME, &config)?;
-
-    let backup_user = crate::backup::backup_user()?;
-    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
-    // set the correct owner/group/permissions while saving file
-    // owner(rw) = root, group(r)= backup
-
-    let options = CreateOptions::new()
-        .perm(mode)
-        .owner(nix::unistd::ROOT)
-        .group(backup_user.gid);
-
-    replace_file(VERIFICATION_CFG_FILENAME, raw.as_bytes(), options)?;
-
-    Ok(())
+    crate::backup::replace_backup_config(VERIFICATION_CFG_FILENAME, raw.as_bytes())
 }
 
 // shell completion helper
-- 
2.30.2