[pbs-devel] [PATCH backup 4/5] pbs-client: make common helper for getting UTF-8 secrets

[Maximiliano Sandoval]

Now that there are three credentials it makes sense to have a common
helper.

Signed-off-by: Maximiliano Sandoval <m.sandoval at proxmox.com>
---
 pbs-client/src/tools/mod.rs | 61 ++++++++++++++++++-------------------
 1 file changed, 30 insertions(+), 31 deletions(-)

diff --git a/pbs-client/src/tools/mod.rs b/pbs-client/src/tools/mod.rs
index 5dd3b6b10..bd553d88b 100644
--- a/pbs-client/src/tools/mod.rs
+++ b/pbs-client/src/tools/mod.rs
@@ -157,6 +157,25 @@ fn get_secret_from_env(base_name: &str) -> Result<Option<String>, Error> {
     Ok(None)
 }
 
+/// Gets a secret or value from the environment.
+///
+/// Checks for an environment variable named `env_variable`, and if missing, it
+/// checks for a system [credential] named `credential_name`. Assumes the secret
+/// is UTF-8 encoded.
+///
+/// [credential]: https://systemd.io/CREDENTIALS/
+fn get_secret_impl(env_variable: &str, credential_name: &str) -> Result<Option<String>, Error> {
+    if let Some(password) = get_secret_from_env(env_variable)? {
+        Ok(Some(password))
+    } else if let Some(password) = get_credential(credential_name)? {
+        String::from_utf8(password)
+            .map(Option::Some)
+            .map_err(|_err| format_err!("credential {credential_name} is not utf8 encoded"))
+    } else {
+        Ok(None)
+    }
+}
+
 /// Gets the backup server's password.
 ///
 /// Looks for a password in the `PBS_PASSWORD` environment variable, if there
@@ -167,15 +186,7 @@ fn get_secret_from_env(base_name: &str) -> Result<Option<String>, Error> {
 ///
 /// [credential]: https://systemd.io/CREDENTIALS/
 pub fn get_password() -> Result<Option<String>, Error> {
-    if let Some(password) = get_secret_from_env(ENV_VAR_PBS_PASSWORD)? {
-        Ok(Some(password))
-    } else if let Some(password) = get_credential(CRED_PBS_PASSWORD)? {
-        String::from_utf8(password)
-            .map(Option::Some)
-            .map_err(|_err| format_err!("non-utf8 password credential"))
-    } else {
-        Ok(None)
-    }
+    get_secret_impl(ENV_VAR_PBS_PASSWORD, CRED_PBS_PASSWORD)
 }
 
 /// Gets an encryption password.
@@ -200,17 +211,11 @@ pub fn get_encryption_password() -> Result<Option<Vec<u8>>, Error> {
 }
 
 pub fn get_default_repository() -> Option<String> {
-    if let Ok(repository) = std::env::var(ENV_VAR_PBS_REPOSITORY) {
-        Some(repository)
-    } else if let Ok(Some(repository)) = get_credential(CRED_PBS_REPOSITORY).inspect_err(|err| {
-        proxmox_log::error!("Could not read credential {CRED_PBS_REPOSITORY}: {err}")
-    }) {
-        String::from_utf8(repository)
-            .inspect_err(|_err| proxmox_log::error!("non-utf8 repository credential"))
-            .ok()
-    } else {
-        None
-    }
+    get_secret_impl(ENV_VAR_PBS_REPOSITORY, CRED_PBS_REPOSITORY)
+        .inspect_err(|err| {
+            proxmox_log::error!("could not read default repository: {err:#}");
+        })
+        .unwrap_or_default()
 }
 
 /// Gets the repository fingerprint.
@@ -224,17 +229,11 @@ pub fn get_default_repository() -> Option<String> {
 ///
 /// [credential]: https://systemd.io/CREDENTIALS/
 pub fn get_fingerprint() -> Option<String> {
-    if let Ok(fingerprint) = std::env::var(ENV_VAR_PBS_FINGERPRINT) {
-        Some(fingerprint)
-    } else if let Ok(Some(fingerprint)) = get_credential(CRED_PBS_FINGERPRINT).inspect_err(|err| {
-        proxmox_log::error!("Could not read credential {CRED_PBS_FINGERPRINT}: {err}")
-    }) {
-        String::from_utf8(fingerprint)
-            .inspect_err(|_err| proxmox_log::error!("non-utf8 fingerprint credential"))
-            .ok()
-    } else {
-        None
-    }
+    get_secret_impl(ENV_VAR_PBS_FINGERPRINT, CRED_PBS_FINGERPRINT)
+        .inspect_err(|err| {
+            proxmox_log::error!("could not read fingerprint: {err:#}");
+        })
+        .unwrap_or_default()
 }
 
 pub fn remove_repository_from_value(param: &mut Value) -> Result<BackupRepository, Error> {
-- 
2.39.5