nix doctor info

Change-Id: Ibe8280da94d0c76bfeb218c9dcb072f0bdbbea4d

src/nix/doctor.cc

@@ -1,14 +1,27 @@
+#include <filesystem>
+#include <fstream>
+#include <iostream>
 #include <sstream>
 
+#include <boost/algorithm/string.hpp>
+
 #include "command.hh"
+#include "eval-settings.hh"
+#include "eval.hh"
+#include "filetransfer.hh"
 #include "logging.hh"
 #include "serve-protocol.hh"
 #include "shared.hh"
 #include "store-api.hh"
+#include "split.hh"
 #include "local-fs-store.hh"
 #include "util.hh"
 #include "worker-protocol.hh"
 
+namespace fs = std::filesystem;
+
+using namespace std::literals::string_view_literals;
+
 using namespace nix;
 
 namespace {
@@ -61,6 +74,36 @@ struct CmdDoctor : StoreCommand
     void run(ref<Store> store) override
     {
         logger->log("Running checks against store uri: " + store->getUri());
+        std::cout << "- system: " << evalSettings.getCurrentSystem() << "\n";
+
+        if (fs::exists("/etc/os-release")) {
+            std::string hostOs = this->getOsDescription();
+            std::cout << "- host os: " << hostOs << "\n";
+        }
+
+        // Now check if multi-user.
+        // FIXME: how actually do we check this?
+        bool isMultiUser = settings.buildUsersGroup != "" || store->getUri() == "daemon";
+        std::cout << "- multi-user?: " << (isMultiUser ? "yes" : "no") << "\n";
+        std::cout << "- sandbox: " << settings.sandboxMode.to_string() << "\n";
+        std::cout << "- version: ";
+        // FIXME: nix-env is what nix-info uses. Is there any reason for us to do the same?
+        try {
+            // XXX
+            printVersion("nix-env:");
+        } catch (Exit const &) {
+            // Ignore.
+        }
+
+        std::cout << "- <nixpkgs>: ";
+        evalSettings.pureEval = false;
+        fileTransferSettings.tries = 0; // FIXME
+        EvalState evalState(SearchPath{}, store);
+        auto *nixpkgsSearch = evalState.parseExprFromString("<nixpkgs>", CanonPath::fromCwd());
+        Value nixpkgsValue;
+        evalState.eval(nixpkgsSearch, nixpkgsValue);
+        //evalState.forceValue(nixpkgsValue, noPos);
+        std::cout << printValue(evalState, nixpkgsValue) << "\n";
 
         if (store.dynamic_pointer_cast<LocalFSStore>()) {
             success &= checkNixInPath();
@@ -73,6 +116,80 @@ struct CmdDoctor : StoreCommand
             throw Exit(2);
     }
 
+    std::string getOsDescription() const
+    {
+        constexpr std::string_view NAME = "NAME=";
+        constexpr std::string_view VERSION = "VERSION=";
+        constexpr std::string_view PRETTY_NAME = "PRETTY_NAME=";
+        constexpr std::string_view BUILD_ID = "BUILD_ID=";
+
+        constexpr auto dequoteStrip = [](std::string_view s) -> std::string_view {
+            return stripChars(s, "\" \n\r");
+        };
+
+        std::vector<std::string> parts;
+        parts.reserve(4);
+
+        if (auto unameCmd = which("uname")) {
+            assert(fs::path(*unameCmd).is_absolute());
+            try {
+                // -sr -> --kernel-name --kernel-release
+                auto unameOutput = runProgram(*unameCmd, false, {"-sr"});
+                parts.emplace_back(trim(unameOutput));
+            } catch (ExecError const & e) {
+                printError("could not run uname to get OS info: %s", e.what());
+            }
+        } else {
+            printError("could not get OS info: uname not found in PATH");
+        }
+
+        std::optional<std::string> name;
+        std::optional<std::string> version;
+        std::optional<std::string> prettyName;
+        std::optional<std::string> buildId;
+
+        try {
+            std::string const contents = readFile("/etc/os-release");
+
+            for (std::string_view const line : splitBy(contents, "\n")) {
+                if (line.starts_with(NAME)) {
+                    name = dequoteStrip(line.substr(NAME.size()));
+                }
+
+                if (line.starts_with(VERSION)) {
+                    version = dequoteStrip(line.substr(VERSION.size()));
+                }
+
+                if (line.starts_with(PRETTY_NAME)) {
+                    prettyName = dequoteStrip(line.substr(PRETTY_NAME.size()));
+                }
+
+                if (line.starts_with(BUILD_ID)) {
+                    buildId = dequoteStrip(line.substr(BUILD_ID.size()));
+                }
+            }
+
+            // Use pretty name, falling back to name and version.
+            if (prettyName.has_value()) {
+                parts.emplace_back(*prettyName);
+            } else if (name.has_value()) {
+                parts.emplace_back(*name);
+                if (version.has_value()) {
+                    parts.emplace_back(*version);
+                }
+            }
+
+            if (buildId.has_value()) {
+                parts.emplace_back(*buildId);
+            }
+
+        } catch (SysError const & e) {
+            printError("could not determine OS from /etc/os-release: %s", e.what());
+        }
+
+        return boost::algorithm::join(parts, ", ");
+    }
+
     bool checkNixInPath()
     {
         PathSet dirs;