Upfront Clarifications Needed:
- Who will be supported by the distribution?
- Implementing partners, the "Galactic" PEPFAR instance and/or the ministries of health?
- What workflow(s) will the distribution support?
- What components are actually included in the package(s)?
- Base software components
- What version of the components are required?
- Customized configurations
- Metadata
- What are the implementation site requirements (if any)?
- Operating system
- Network connectivity
- Minimum hardware requirement
- Level of implementer expertise
- How often will the contents of the distribution need to change?
Different Types of Packaging
Binary / Standalone
A binary or standalone package usually consists of a .zip or .tar.gz file that will first need to extracted. After extraction, a binary or script is executed to run the application.
Pros
- No additional software should need to be installed.
- Does not require any specific hardware support.
- Does not require internet access for installation.
- Performance is great.
- Easiest to install.
Cons
- Specific binaries need to be created for each OS supported.
- No easy way of getting updates.
- Requires extra effort from software maintainers to put the standalone package together.
Installer Packages
Installer packages consist of platform specific packages that, when executed, install the application to a specific directory and also can run some post installation configuration. File extensions typically are .exe or .msi for Windows and .deb or .rpm for linux.
Pros
- Does not require any specific hardware support.
- Performance is great.
- Easily updated if configured to use a repository.
- Easy to install using native OS tools.
Cons
- May require extra software dependencies.
- Packages are specific to OS.
- Installation Requires internet Access.
Virtual Machine Image
Virtual machine images consist of a base operating system with the application preinstalled and preconfigured. This is then distributed as a .ova or .vmdk files.
Pros
- Does not require a specific base OS.
- Easy to install.
- Easy to upgrade after initial install. *(If updating packages in the virtual machine.)
Cons
- Requires VM software to be installed (e.g. VirtualBox)
- Requires Hardware support
- Performance is not as good as native.
Docker image
A docker images consists of virtual container containing a minimal OS and the application pre installed and preconfigured. The most common form of distribution is in a source repository, or through Docker Hub.
Pros
- Performance is very close to native.
- Easy to get new updates once installed.
Cons
- Requires docker and base os it be installed before running image.
- Requires Hardware support on non linux OS.
- Host OS and image OS must match. (e.g. Linux os will run only linux images.)
- Requires internet access to get base image
Cloud Host Image
A cloud host image is a pre made virtual machine image built to run on a specific cloud hosting provider. The most common format is Amazon's Amazon Machine Image(ami).
Pros
- Easy to setup when using Amazon EC2.
- Performance is good with the option to scale up using EC2.
- Easy to upgrade after initial install. *(If updating packages in the vm.)
Cons
- Requires internet access for installation AND operation.
- Cost of running EC2 instances.
| Packaging Solution | Requires Additional Software | Requires Hardware Support | Requires Operating System Support | Requires Internet Access | Performance(1-5) | Ease of Install(1-5) | Easy to update |
|---|---|---|---|---|---|---|---|
| Standalone Binary | No | No | Standalone is specific to OS | No | 5 | 5 | No |
| Installer Packages | Yes, dependencies | No | Packages are specific to OS | Yes | 5 | 4 | Yes |
| Virtual Machine Images | Yes, VM software | Yes, AMD-V or VT-x | No | No | 3 | 4 | Yes* |
| Docker Images | Yes, docker and OS img | Yes, if using boot2docker | Host os and docker OS must match | Yes | 4.5 | 2 | Yes |
| Cloud Host Images | N/A | N/A | N/A | Yes, even for operation. | 5 | 5* | Yes* |
Blockers for each packaging method
Standalone Binary
You should not use the standalone binary if any of these are true.
- Need easy updates in the future.
- Using a non supported OS
Installer Packages
You should not use the installer packages if any of the following are true.
- No internet access during install. This prevents installation of additional software.
- Using a non supported OS.
Virtual Machine Images
You should not use the virtual machine images if any of the following are true.
- Do not have hardware support for virtualization.
- If you do not have internet access and do not have virtualization software already installed.
- Need the maximum amount of performance from your hardware.
Docker Image
You should not use the Docker image if any of the following are true.
- You need an easy to install method.
- Using a non linux OS and do not meet the hardware virtualization requirements.
- No internet access during install and do not have docker and all images needed to run the application.
Cloud Host Image
You should not use the Cloud hosting image if any of the following are true.
- You do not have reliable internet access.
- You need your data on site.
- Cloud provider is too expensive.