Merge pull request #625 from anmenaga/issue_618

Fix built-in resource and settings discovery when dsc is invoked using a symlink

Author: SteveL-MSFT

dsc_lib/src/discovery/command_discovery.rs

@@ -24,6 +24,7 @@ use tracing::{debug, info, trace, warn, warn_span};
 use tracing_indicatif::span_ext::IndicatifSpanExt;
 
 use crate::util::get_setting;
+use crate::util::get_exe_path;
 
 pub struct CommandDiscovery {
     // use BTreeMap so that the results are sorted by the typename, the Vec is sorted by version
@@ -135,7 +136,7 @@ impl CommandDiscovery {
 
         // if exe home is not already in PATH env var then add it to env var and list of searched paths
         if !using_custom_path {
-            if let Some(exe_home) = env::current_exe()?.parent() {
+            if let Some(exe_home) = get_exe_path()?.parent() {
                 let exe_home_pb = exe_home.to_path_buf();
                 if paths.contains(&exe_home_pb) {
                     trace!("Exe home is already in path: {}", exe_home.to_string_lossy());

dsc_lib/src/util.rs

@@ -3,6 +3,7 @@
 
 use crate::dscerror::DscError;
 use serde_json::Value;
+use std::fs;
 use std::fs::File;
 use std::io::BufReader;
 use std::path::PathBuf;
@@ -79,7 +80,7 @@ pub fn get_setting(value_name: &str) -> Result<DscSettingValue, DscError> {
     let mut result: DscSettingValue = DscSettingValue::default();
     let mut settings_file_path : PathBuf;
 
-    if let Some(exe_home) = env::current_exe()?.parent() {
+    if let Some(exe_home) = get_exe_path()?.parent() {
         // First, get setting from the default settings file
         settings_file_path = exe_home.join(DEFAULT_SETTINGS_FILE_NAME);
         if let Ok(v) = load_value_from_json(&settings_file_path, DEFAULT_SETTINGS_SCHEMA_VERSION) {
@@ -141,6 +142,24 @@ fn load_value_from_json(path: &PathBuf, value_name: &str) -> Result<serde_json::
     Err(DscError::NotSupported(value_name.to_string()))
 }
 
+/// Gets path to the current dsc process.
+/// If dsc is started using a symlink, this functon returns target of the symlink.
+///
+/// # Errors
+///
+/// Will return `Err` if path to the current exe can't be retrived.
+pub fn get_exe_path() -> Result<PathBuf, DscError> {
+    if let Ok(exe) = env::current_exe() {
+        if let Ok(target_path) = fs::read_link(exe.clone()) {
+            return Ok(target_path);
+        };
+
+        return Ok(exe);
+    }
+
+    Err(DscError::NotSupported("Can't get the path to dsc executable".to_string()))
+}
+
 #[cfg(target_os = "windows")]
 fn get_settings_policy_file_path() -> String
 {