Container images may be generated from a backup system that includes a backup of one or more applications from a computing system of an entity. During a backup process, an application can be identified and its storage location in a secondary storage can be tracked or saved in a backup index. Configuration information and data or files created by user interaction with the application can be backed up and the location of the backed up data or files may be stored in the backup index along with the location of the configuration information. Using the backup index, a container image can be created that includes a selected application, its configuration information, and data, if any, created by the application. The container image can be generated from the backup stored in the secondary storage.