Docker: Check image exists first before trying to launch it

Otherwise we will trigger a bunch of expensive calls that are not necessary.

Change-Id: I9763b251e828f9f3683f120ee473ce6ad7ca84eb
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

src/plugins/docker/dockerapi.cpp

@@ -75,6 +75,23 @@ bool DockerApi::isContainerRunning(const QString &containerId)
     return false;
 }
 
+bool DockerApi::imageExists(const QString &imageId)
+{
+    Process process;
+    FilePath dockerExe = dockerClient();
+    if (dockerExe.isEmpty() || !dockerExe.isExecutableFile())
+        return false;
+
+    process.setCommand(
+        CommandLine(dockerExe, QStringList{"image", "inspect", imageId, "--format", "{{.Id}}"}));
+    process.runBlocking();
+
+    if (process.exitCode() == 0)
+        return true;
+
+    return false;
+}
+
 void DockerApi::checkCanConnect(bool async)
 {
     if (async) {

src/plugins/docker/dockerapi.h

@@ -44,6 +44,7 @@ public:
     QFuture<Utils::Result<QList<Network>>> networks();
 
     bool isContainerRunning(const QString &containerId);
+    bool imageExists(const QString &imageId);
 
 signals:
     void dockerDaemonAvailableChanged();

src/plugins/docker/dockerdevice.cpp

@@ -247,6 +247,9 @@ public:
         if (DeviceFileAccess *fileAccess = m_fileAccess.readLocked()->get())
             return fileAccess;
 
+        if (!DockerApi::instance()->imageExists(q->repoAndTag()))
+            return nullptr;
+
         SynchronizedValue<std::unique_ptr<DeviceFileAccess>>::unique_lock fileAccess
             = m_fileAccess.writeLocked();
         if (*fileAccess)
@@ -1003,6 +1006,8 @@ Result<QString> DockerDevicePrivate::updateContainerAccess()
         return make_unexpected(Tr::tr("Device is shut down"));
     if (DockerApi::isDockerDaemonAvailable(false).value_or(false) == false)
         return make_unexpected(Tr::tr("Docker system is not reachable"));
+    if (!DockerApi::instance()->imageExists(q->repoAndTag()))
+        return make_unexpected(Tr::tr("Docker image \"%1\" not found.").arg(q->repoAndTag()));
 
     auto lockedThread = m_deviceThread.writeLocked();
     if (*lockedThread)