Re-add .NET deployer TA plus CI fixes (#5957)

* Revert "Revert "Adds the .NET deployer TA (#5949)" (#5956)"

This reverts commit e99f1da.

* Ensure that main CI is clean with new code

* Allow manual runs of build-and-test

* Fix include casing

* Lint fixes

Author: pjanotti

.github/workflows/build-and-test.yml

@@ -19,6 +19,7 @@ on:
       - 'go.sum'
       - '!**.md'
       - '!packaging/**'
+  workflow_dispatch: # Allows manual execution of the workflow
 
 concurrency:
   group: build-and-test-${{ github.event.pull_request.number || github.ref }}

packaging/dotnet-instr-deployer-add-on/.gitignore

@@ -0,0 +1,7 @@
+# Ignore built or downloaded assets
+assets/windows_x86_64/bin/*.exe
+assets/windows_x86_64/bin/*.psm1
+assets/windows_x86_64/bin/*.zip
+
+# Ignore the directory with the compressed package to be distributed
+out/

packaging/dotnet-instr-deployer-add-on/Makefile

@@ -0,0 +1,41 @@
+include ../../Makefile.Common
+
+MOD_INPUT_NAME = splunk_otel_dotnet_deployer
+
+.PHONY: all
+all: download-dotnet-assets build pack
+
+.PHONY: download-dotnet-assets
+download-dotnet-assets:
+	@echo "Downloading .NET assets..."
+	@for asset in Splunk.OTel.DotNet.psm1 splunk-opentelemetry-dotnet-windows.zip; do \
+		if [ ! -f ./assets/windows_x86_64/bin/$${asset} ]; then \
+			echo " > Downloading $${asset}..."; \
+			curl -s -L https://github.com/signalfx/splunk-otel-dotnet/releases/latest/download/$${asset} -o ./assets/windows_x86_64/bin/$${asset}; \
+		else \
+			echo " > $${asset} already exists, skipping download."; \
+		fi \
+	done
+
+.PHONY: build
+build: ./assets/windows_x86_64/bin/$(MOD_INPUT_NAME).exe
+./assets/windows_x86_64/bin/$(MOD_INPUT_NAME).exe: $(shell find ./ -name '*.go')
+	@echo "Building executable ..."
+	@go build -o ./assets/windows_x86_64/bin/ ./cmd/$(MOD_INPUT_NAME)/...
+
+.PHONY: pack
+pack:
+	@echo "Packing add-on ..."
+	@if [ ! -d ./out/distribution/ ]; then mkdir -p ./out/distribution/; fi
+	@tar -C ./assets/  --transform='s,^,$(MOD_INPUT_NAME)/,' -hcz -f ./out/distribution/$(MOD_INPUT_NAME).tgz .
+
+.PHONY: clean
+clean:
+	@echo "Cleaning..."
+	@if [ -f ./assets/windows_x86_64/bin/$(MOD_INPUT_NAME).exe ]; then rm -rf ./assets/windows_x86_64/bin/$(MOD_INPUT_NAME).exe; fi
+	@if [ -f ../out/distribution/ ]; then rm -rf ./out/distribution/; fi
+
+.PHONY: gotest
+gotest:
+	@echo "Running golang tests..."
+	@go test $${GOTEST_OPTS:- -v -race} ./...

packaging/dotnet-instr-deployer-add-on/README.md

@@ -0,0 +1,72 @@
+# Splunk OpenTelemetry .NET Deployer
+
+The Splunk OpenTelemetry .NET Deployer is a technical add-on to be used with
+Splunk Enterprise to facilitate the deployment of the
+[Splunk Distribution of OpenTelemetry .NET](https://docs.splunk.com/observability/en/gdi/get-data-in/application/otel-dotnet/get-started.html).
+It automates the setup process, ensuring that your .NET
+applications are properly configured to send telemetry data to Splunk
+Observability Cloud.
+
+It assumes that the Splunk OpenTelemetry Collector is already deployed and
+configured to receive telemetry data from your .NET applications.
+
+## Installation
+
+It follows the standard installation process for Splunk apps and add-ons.
+Notice that the technical add-on is not a standalone application, it is meant
+to be run under `splunkd` control.
+
+__Note:__ the technical add-on is only available for Windows x86_64 and requires
+`splunkd` to be running under a user with administrative privileges.
+
+## Configuration
+
+See the [inputs.conf.spec](./assets/README/inputs.conf.spec) file for the available
+configuration options.
+
+## Development
+
+This project was developed on Windows, using `MINGW64` tools and the `bash`
+provided by Git for Windows. Check the [Makefile](./Makefile) for the available
+targets - the default target generates the technical add-on under
+`./out/distribution`.
+
+### Sources
+
+#### `./assets/`
+
+Mimics the structure of the technical add-on, notice the
+[`.gitignore`](./.gitignore) file to
+identify which assets are built and which are not.
+
+It can be copied directly to a Splunk Enterprise instance to install the
+technical add-on. __Note:__ the name of the directory must be the same as the
+name of the technical add-on.
+
+#### `./cmd/splunk_otel_dotnet_deployer/`
+
+Contains the source code for the deployer. It is a simple Go application that
+reads the input XML from the `stdin` and calls a wrapper PowerShell script to
+control the installation process.
+
+#### `./internal/`
+
+Contains the internal packages used by the deployer that in principle could
+be used by other technical add-ons. Currently only contains a type to read the
+input XML.
+
+### Manual run of the deployer
+
+To manually run the deployer locally, use the following command:
+
+```PowerShell
+> cd .\assets\windows_x86_64\bin
+
+> Get-Content ..\..\..\internal\modularinput\testdata\install.inputs.xml | .\splunk_otel_dotnet_deployer.exe
+```
+
+The application will generate output on the console. If you also want the log
+file you need to define the `SPLUNK_HOME` environment variable, pointing to an
+existing directory. The log file will be created under
+`$SPLUNK_HOME/var/log/splunk/splunk_otel_dotnet_deployer.log`. You need to
+create the directory structure, including 'var/log/splunk' if it does not exist.

packaging/dotnet-instr-deployer-add-on/assets/README/inputs.conf.spec

@@ -0,0 +1,5 @@
+[splunk_otel_dotnet_deployer://<name>]
+uninstall = <boolean>
+* By default it always attempt to install the Splunk Distribution of 
+  OpenTelemetry .NET, set to "true" to uninstall.
+* Default = false

packaging/dotnet-instr-deployer-add-on/assets/default/app.conf

@@ -0,0 +1,16 @@
+[install]
+state = enabled
+is_configured = false
+build = 1
+
+[ui]
+is_visible = false
+label = Splunk OpenTelemetry .NET Deployer
+
+[launcher]
+author = Splunk, Inc.
+description = A Splunk Technical Add-on that deploys the Splunk Distribution of OpenTelemetry .NET.
+version = 1.0.0
+
+[package]
+id = splunk_otel_dotnet_deployer

packaging/dotnet-instr-deployer-add-on/assets/default/inputs.conf

@@ -0,0 +1,2 @@
+[splunk_otel_dotnet_deployer://splunk_otel_dotnet_deployer]
+uninstall = false

packaging/dotnet-instr-deployer-add-on/assets/static/appIcon.png

@@ -0,0 +1,54 @@
+<#
+.SYNOPSIS
+This script drives the installation of the Splunk Distribution of OpenTelemetry .NET.
+
+.DESCRIPTION
+This script is intended to be called by the splunk_otel_dotnet_deployer.exe as
+the later is launched by splunkd with proper environment variables and configuration.
+
+.PARAMETER uninstall
+If present, the script will uninstall the Splunk Distribution of OpenTelemetry .NET.
+
+#>
+
+param (
+    [switch]$uninstall
+)
+
+$ErrorActionPreference = "Stop"
+$ProgressPreference = "SilentlyContinue"
+
+$scriptPath = $MyInvocation.MyCommand.Path
+$scriptDir = Split-Path $scriptPath
+
+$modulePath = Join-Path $scriptDir "Splunk.OTel.DotNet.psm1"
+Import-Module $modulePath
+
+$otelSDKInstallVersion = Get-OpenTelemetryInstallVersion
+
+if ($uninstall) {
+    if ($otelSDKInstallVersion) {
+        # TODO: Is it necessary to uninstall for IIS specifically?
+        Write-Host "Uninstalling Splunk Distribution of OpenTelemetry .NET ..."
+        Uninstall-OpenTelemetryCore
+        Write-Host "Splunk Distribution of OpenTelemetry .NET uninstalled successfully"
+    } else {
+        Write-Host "Nothing to do since Splunk Distribution of OpenTelemetry .NET is not installed"
+    }
+# Install the SDK if it is not already installed
+} elseif ($otelSDKInstallVersion) {
+    Write-Host "Nothing to do since Splunk Distribution of OpenTelemetry .NET is already installed. OpenTelelemetry .NET SDK version: $otelSDKInstallVersion"
+} else {
+    Write-Host "Installing Splunk Distribution of OpenTelemetry .NET ..."
+    $zipPath = Join-Path $scriptDir "splunk-opentelemetry-dotnet-windows.zip"
+    Install-OpenTelemetryCore -LocalPath $zipPath
+
+    $w3svc = Get-Service -name "W3SVC" -ErrorAction SilentlyContinue
+    $was = Get-Service -name "WAS" -ErrorAction SilentlyContinue
+    if ($w3svc -And $was) {
+        Write-Host "Registering OpenTelemetry for IIS ..."
+        Register-OpenTelemetryForIIS
+    }
+
+    Write-Host "Splunk Distribution of OpenTelemetry .NET installed successfully"
+}

packaging/dotnet-instr-deployer-add-on/assets/static/appIcon_2x.png

@@ -0,0 +1,28 @@
+// Copyright Splunk, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !windows
+// +build !windows
+
+package main
+
+import (
+	"os"
+
+	"github.com/splunk/splunk_otel_dotnet_deployer/internal/modularinput"
+)
+
+func runDeployer(_ *modularinput.Input, _, _, _ *os.File) error {
+	panic("OS not supported")
+}

packaging/dotnet-instr-deployer-add-on/assets/windows_x86_64/bin/installer-wrapper.ps1

@@ -0,0 +1,97 @@
+// Copyright Splunk, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build windows
+// +build windows
+
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+
+	"github.com/splunk/splunk_otel_dotnet_deployer/internal/modularinput"
+)
+
+const (
+	wrapperScript = "installer-wrapper.ps1"
+)
+
+func runDeployer(input *modularinput.Input, stdin, stdout, stderr *os.File) error {
+	// Launch the wrapper script using PowerShell capturing the output
+	// and error streams and sending them to the stdout and stderr streams
+	// of the deployer.
+
+	// The wrapper script is expected to be in the same directory as the deployer.
+	// Get the path to the deployer executable.
+	deployerPath, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("failed to get the path to the deployer executable: %w", err)
+	}
+
+	scriptDir := filepath.Dir(deployerPath)
+	scriptPath := filepath.Join(scriptDir, wrapperScript)
+	if _, err := os.Stat(scriptPath); err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("wrapper script not found at %s", scriptPath)
+		}
+		return fmt.Errorf("failed to check if wrapper script exists: %w", err)
+	}
+
+	// Launch the wrapper script using PowerShell.
+	args := []string{
+		"-ExecutionPolicy", "ByPass",
+		"-File", scriptPath,
+	}
+	args = append(args, scriptArgs(input)...)
+	log.Printf("Running: powershell.exe args: %v\n", args)
+	cmd := exec.Command("powershell.exe", args...)
+
+	var stdBuf, errBuf strings.Builder
+	cmd.Stdin = stdin
+	cmd.Stdout = &stdBuf
+	cmd.Stderr = &errBuf
+
+	err = cmd.Run()
+
+	log.Printf("Wrapper stdout:\n%s\n", stdBuf.String())
+	log.Printf("Wrapper stderr:\n%s\n", errBuf.String())
+
+	return err
+}
+
+func scriptArgs(input *modularinput.Input) []string {
+	var args []string
+	var configStanza modularinput.Stanza
+	for _, stanza := range input.Configuration.Stanza {
+		if stanza.Name == modularinputName+"://"+modularinputName {
+			configStanza = stanza
+			break
+		}
+	}
+
+	for _, param := range configStanza.Param {
+		switch param.Name {
+		case "uninstall":
+			if param.Value == "true" {
+				args = append(args, "-uninstall")
+			}
+		}
+	}
+	return args
+}