[libcalamares] Begin implementing Runner

This copies a bunch of code from the System methods for running,
and then #if 0's them to get it to compile. Add some basic
directory-management.

src/libcalamares/CMakeLists.txt

@@ -77,6 +77,7 @@ set( libSources
     utils/Permissions.cpp
     utils/PluginFactory.cpp
     utils/Retranslator.cpp
+    utils/Runner.cpp
     utils/String.cpp
     utils/UMask.cpp
     utils/Variant.cpp

src/libcalamares/utils/Runner.cpp

@@ -10,8 +10,82 @@
 
 #include "Runner.h"
 
-namespace
+#include "GlobalStorage.h"
+#include "JobQueue.h"
+#include "utils/Logger.h"
+
+/** @brief Descend from directory, always relative
+ *
+ * If @p subdir begins with a "/" or "../" or "./" those are stripped
+ * until none are left, then changes @p directory into that
+ * subdirectory.
+ *
+ * Returns @c false if the @p subdir doesn't make sense.
+ */
+STATICTEST bool
+relativeChangeDirectory( QDir& directory, const QString& subdir )
 {
+    const QString rootPath = directory.absolutePath();
+    const QString concatenatedPath = rootPath + '/' + subdir;
+    const QString relPath = QDir::cleanPath( concatenatedPath );
+
+    if ( !relPath.startsWith( rootPath ) )
+    {
+        cWarning() << "Relative path" << subdir << "escapes from" << rootPath;
+        return false;
+    }
+
+    return directory.cd( relPath );
+}
+
+
+STATICTEST std::pair< bool, QDir >
+calculateWorkingDirectory( Calamares::Utils::RunLocation location, QString directory )
+{
+    Calamares::GlobalStorage* gs
+        = Calamares::JobQueue::instance() ? Calamares::JobQueue::instance()->globalStorage() : nullptr;
+
+    if ( location == Calamares::Utils::RunLocation::RunInTarget )
+    {
+        if ( !gs || !gs->contains( "rootMountPoint" ) )
+        {
+            cWarning() << "No rootMountPoint in global storage, while RunInTarget is specified";
+            return std::make_pair( false, QDir() );
+        }
+
+        QDir rootMountPoint( gs->value( "rootMountPoint" ).toString() );
+        if ( !rootMountPoint.exists() )
+        {
+            cWarning() << "rootMountPoint points to a dir which does not exist";
+            return std::make_pair( false, QDir() );
+        }
+
+        if ( !directory.isEmpty() )
+        {
+
+            if ( !relativeChangeDirectory( rootMountPoint, directory ) || !rootMountPoint.exists() )
+            {
+                cWarning() << "Working directory" << directory << "does not exist in target";
+                return std::make_pair( false, QDir() );
+            }
+        }
+        return std::make_pair( true, rootMountPoint );  // Now changed to subdir
+    }
+    else
+    {
+        QDir root;
+        if ( !directory.isEmpty() )
+        {
+            root = QDir::root();
+
+            if ( !relativeChangeDirectory( root, directory ) || !root.exists() )
+            {
+                cWarning() << "Working directory" << directory << "does not exist in host";
+                return std::make_pair( false, QDir() );
+            }
+        }
+        return std::make_pair( true, root );  // Now changed to subdir
+    }
 }
 
 namespace Calamares
@@ -21,25 +95,122 @@ namespace Utils
 
 struct Runner::Private
 {
-    QStringList m_command;
-    RunLocation m_location = RunLocation::RunInHost;
+    QProcess m_process;
 };
 
+
 Runner::Runner() {}
-Runner::Runner( const QStringList& command )
-    : d( std::make_unique< Private >() )
-{
-    d->m_command = command;
-}
 
-Runner::~Runner() {}
-
-Runner&
-Runner::setCommand( const QStringList& command )
-{
-    d->m_command = command;
-    return *this;
-}
 
 }  // namespace Utils
 }  // namespace Calamares
+
+
+Calamares::Utils::Runner::Runner( const QStringList& command )
+{
+    setCommand( command );
+}
+
+Calamares::Utils::Runner::~Runner() {}
+
+Calamares::Utils::ProcessResult
+Calamares::Utils::Runner::run()
+{
+    if ( m_command.isEmpty() )
+    {
+        cWarning() << "Cannot run an empty program list";
+        return ProcessResult::Code::FailedToStart;
+    }
+
+    auto [ ok, workingDirectory ] = calculateWorkingDirectory( m_location, m_directory );
+    if ( !ok || !workingDirectory.exists() )
+    {
+        // Warnings have already been printed
+        return ProcessResult::Code::NoWorkingDirectory;
+    }
+
+
+    QProcess process;
+    process.setProcessChannelMode( QProcess::MergedChannels );
+    process.setWorkingDirectory( workingDirectory.absolutePath() );
+    if ( m_location == RunLocation::RunInTarget )
+    {
+        process.setProgram( "chroot" );
+        process.setArguments( QStringList { workingDirectory.absolutePath() } << m_command );
+    }
+    else
+    {
+        process.setProgram( "env" );
+        process.setArguments( m_command );
+    }
+
+    return ProcessResult::Code::Crashed;
+#if 0
+    if ( !workingPath.isEmpty() )
+    {
+        if ( QDir( workingPath ).exists() )
+        {
+            process.setWorkingDirectory( QDir( workingPath ).absolutePath() );
+        }
+        else
+        {
+            cWarning() << "Invalid working directory:" << workingPath;
+            return ProcessResult::Code::NoWorkingDirectory;
+        }
+    }
+
+    cDebug() << Logger::SubEntry << "Running" << program << RedactedList( arguments );
+    process.start();
+    if ( !process.waitForStarted() )
+    {
+        cWarning() << "Process" << args.first() << "failed to start" << process.error();
+        return ProcessResult::Code::FailedToStart;
+    }
+
+    if ( !stdInput.isEmpty() )
+    {
+        process.write( stdInput.toLocal8Bit() );
+    }
+    process.closeWriteChannel();
+
+    if ( !process.waitForFinished( timeoutSec > std::chrono::seconds::zero()
+                                   ? ( static_cast< int >( std::chrono::milliseconds( timeoutSec ).count() ) )
+                                   : -1 ) )
+    {
+        cWarning() << "Process" << args.first() << "timed out after" << timeoutSec.count() << "s. Output so far:\n"
+                   << Logger::NoQuote << process.readAllStandardOutput();
+        return ProcessResult::Code::TimedOut;
+    }
+
+    QString output = QString::fromLocal8Bit( process.readAllStandardOutput() ).trimmed();
+
+    if ( process.exitStatus() == QProcess::CrashExit )
+    {
+        cWarning() << "Process" << args.first() << "crashed. Output so far:\n" << Logger::NoQuote << output;
+        return ProcessResult::Code::Crashed;
+    }
+
+    auto r = process.exitCode();
+    bool showDebug = ( !Calamares::Settings::instance() ) || ( Calamares::Settings::instance()->debugMode() );
+    if ( r == 0 )
+    {
+        if ( showDebug && !output.isEmpty() )
+        {
+            cDebug() << Logger::SubEntry << "Finished. Exit code:" << r << "output:\n" << Logger::NoQuote << output;
+        }
+    }
+    else  // if ( r != 0 )
+    {
+        if ( !output.isEmpty() )
+        {
+            cDebug() << Logger::SubEntry << "Target cmd:" << RedactedList( args ) << "Exit code:" << r << "output:\n"
+                     << Logger::NoQuote << output;
+        }
+        else
+        {
+            cDebug() << Logger::SubEntry << "Target cmd:" << RedactedList( args ) << "Exit code:" << r << "(no output)";
+        }
+    }
+    return ProcessResult( r, output );
+#endif
+}

src/libcalamares/utils/Runner.h

@@ -15,6 +15,7 @@
 
 #include <QDir>
 #include <QObject>
+#include <QProcess>
 #include <QStringList>
 
 #include <chrono>
@@ -27,25 +28,88 @@ namespace Utils
 {
 
 using RunLocation = CalamaresUtils::System::RunLocation;
+using ProcessResult = CalamaresUtils::ProcessResult;
 
-/** @brief A Runner wraps a process and handles running it and signalling */
+/** @brief A Runner wraps a process and handles running it and processing output
+ *
+ * This is basically a QProcess, but handles both running in the
+ * host system (natively) or in the target (by calling chroot).
+ * It has an output signal that handles output one line at a time
+ * (unlike QProcess that lets you do the buffering yourself).
+ * This output processing is only enabled if you do so explicitly.
+ */
 class Runner : public QObject
 {
     Q_OBJECT
 
 public:
+    /** @brief Create an empty runner
+     *
+     * This is a runner with no commands, nothing; call set*() methods
+     * to configure it.
+     */
     Runner();
+    /** @brief Create a runner with a specified command
+     *
+     * Equivalent to Calamares::Utils::Runner::Runner()
+     */
     Runner( const QStringList& command );
     virtual ~Runner() override;
 
-    Runner& setCommand( const QStringList& command );
-    Runner& setLocation( RunLocation r );
-    Runner& setWorkingDirectory( const QString& directory );
-    Runner& setWorkingDirectory( const QDir& directory );
-    Runner& setTimeout( std::chrono::seconds timeout );
-    Runner& setInput( const QString& stdin );
+    Runner& setCommand( const QStringList& command )
+    {
+        m_command = command;
+        return *this;
+    }
+    Runner& setLocation( RunLocation r )
+    {
+        m_location = r;
+        return *this;
+    }
+    Runner& setWorkingDirectory( const QDir& directory )
+    {
+        m_directory = directory.absolutePath();
+        return *this;
+    }
+    Runner& setWorkingDirectory( const QString& directory )
+    {
+        m_directory = directory;
+        return *this;
+    }
+    Runner& setTimeout( std::chrono::seconds timeout )
+    {
+        m_timeout = timeout;
+        return *this;
+    }
+    Runner& setInput( const QString& stdin )
+    {
+        m_input = stdin;
+        return *this;
+    }
+
+    Runner& enableOutputProcessing( bool enable = true )
+    {
+        m_output = enable;
+        return *this;
+    }
+
+    ProcessResult run();
+
+signals:
+    void output( QString line );
 
 private:
+    // What to run, and where.
+    QStringList m_command;
+    QString m_directory;
+    RunLocation m_location { RunLocation::RunInHost };
+
+    // Settings for when it actually runs
+    QString m_input;
+    std::chrono::milliseconds m_timeout { 0 };
+    bool m_output = false;
+
+    // Internals for when it really does run
     struct Private;
     std::unique_ptr< Private > d;
 };