Add context() function and refactor osinfo

Author: SteveL-MSFT

build.ps1

@@ -343,6 +343,7 @@ if (!$SkipBuild) {
         "dsc",
         "dscecho",
         "extensions/bicep",
+        "lib/osinfo_lib",
         "osinfo",
         "powershell-adapter",
         'resources/PSScript',

dsc/Cargo.lock

@@ -483,4 +483,24 @@ Describe 'tests for function expressions' {
     $LASTEXITCODE | Should -Be 0 -Because (Get-Content $TestDrive/error.log -Raw)
     ($out.results[0].result.actualState.output | Out-String) | Should -BeExactly ($expected | Out-String)
   }
+
+  It 'context function works' {
+    $config_yaml = @"
+            `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+            resources:
+            - name: Echo
+              type: Microsoft.DSC.Debug/Echo
+              properties:
+                output: "[context()]"
+"@
+    $out = dsc -l trace config get -i $config_yaml 2>$TestDrive/error.log | ConvertFrom-Json
+    $LASTEXITCODE | Should -Be 0 -Because (Get-Content $TestDrive/error.log -Raw)
+    $context = $out.results[0].result.actualState.output
+    $os = osinfo | ConvertFrom-Json
+    $context.os.family | Should -BeExactly $os.family
+    $context.os.version | Should -BeExactly $os.version
+    $context.os.bitness | Should -BeExactly $os.bitness
+    $context.os.architecture | Should -BeExactly $os.architecture
+    $context.security | Should -BeExactly $out.metadata.'Microsoft.DSC'.securityContext
+  }
 }

dsc/tests/dsc_functions.tests.ps1

@@ -23,6 +23,7 @@ jsonschema = { version = "0.33", default-features = false }
 linked-hash-map = "0.5"
 murmurhash64 = "0.3"
 num-traits = "0.2"
+osinfo_lib = { path = "../lib/osinfo_lib" }
 path-absolutize = { version = "3.1" }
 regex = "1.11"
 rt-format = "0.3"

dsc_lib/Cargo.lock

@@ -0,0 +1,43 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+use crate::DscError;
+use crate::configure::{context::Context as ConfigContext, config_doc::SecurityContextKind};
+use crate::functions::{FunctionArgKind, Function, FunctionCategory, FunctionMetadata};
+use osinfo_lib::OsInfo;
+use rust_i18n::t;
+use serde::Serialize;
+use serde_json::Value;
+use tracing::debug;
+
+#[derive(Debug, Serialize)]
+pub struct ContextInfo {
+    os: OsInfo,
+    security: SecurityContextKind,
+}
+
+pub struct Context {}
+
+impl Function for Context {
+    fn get_metadata(&self) -> FunctionMetadata {
+        FunctionMetadata {
+            name: "context".to_string(),
+            description: t!("functions.context.description").to_string(),
+            category: FunctionCategory::System,
+            min_args: 0,
+            max_args: 0,
+            accepted_arg_ordered_types: vec![],
+            remaining_arg_accepted_types: None,
+            return_types: vec![FunctionArgKind::Object],
+        }
+    }
+
+    fn invoke(&self, _args: &[Value], config_context: &ConfigContext) -> Result<Value, DscError> {
+        debug!("{}", t!("functions.add.invoked"));
+        let context = ContextInfo {
+            os: OsInfo::new(false),
+            security: config_context.security_context.clone(),
+        };
+        Ok(serde_json::to_value(context).unwrap())
+    }
+}

dsc_lib/Cargo.toml

@@ -20,6 +20,7 @@ pub mod bool;
 pub mod coalesce;
 pub mod concat;
 pub mod contains;
+pub mod context;
 pub mod copy_index;
 pub mod create_array;
 pub mod create_object;
@@ -134,6 +135,7 @@ impl FunctionDispatcher {
             Box::new(coalesce::Coalesce{}),
             Box::new(concat::Concat{}),
             Box::new(contains::Contains{}),
+            Box::new(context::Context{}),
             Box::new(copy_index::CopyIndex{}),
             Box::new(create_array::CreateArray{}),
             Box::new(create_object::CreateObject{}),