Fedora Server: Expanding Throughout the Galaxy
Three years ago, Fedora embarked on a new initiative that we collectively refer to as Fedora.next . As part of this initiative, we decided to start curating deliverable artifacts around specific use-cases rather than the one-size-fits-all approach of Fedora 20 and earlier. One of those specific use-cases was to meet the needs of “server administrators”. And thus, the Fedora Server Edition was born.
One of the earliest things that we did after creating the Fedora Server Working Group (Server WG from here on) was to perform what in the corporate world might be called a “gap analysis”. What this means is that we looked at Fedora from the perspective of the server administrator “ personas ” we had created and tried to understand their pain points (particularly in contrast to how things function on competitive platforms such as Microsoft windows Server).
The most obvious gap that we identified was the relative difficulty of getting started with Fedora Server Edition at all.With Microsoft Windows Server, the first experience after logging in is to be presented with a tool called Server Manager that provides basic (graphical) information about the system as well as presenting the user with a list of things that they might want this server to do. It then walks them through a guided installation of those core features (such as domain controllerservices, remote desktop services and so on). With Fedora, a default install would get you a bash prompt with no guidance; typing “help” would only lead to the extremely expert-focused help documentation for the bash shell itself.
OK, advantage Windows here. So how do we address that? Server WG had agreed early on that we were not willing require a desktop environment for server systems. We instead set our sights on a fledgling project called Cockpit , which was gaining traction and looked to providean excellent user experience without requiring a local display it’s a web-based admin console and so can be accessed by users running the operating system of their choice.
Once Cockpit was established as the much-friendlier initial experience for Fedora Server, we started to look at the second part of the problem that we needed to solve: that of simplified deployment of key infrastructure components. To that end, we started the development of a tool that we could integrate with the Cockpit admin console and provide the actual deployment implementation. What we came up with was a python project that we called rolekit that would provide a fairly simple local D-BUS API that Cockpit would be able to call out to in order to deploythe requested services.
While our intentions were good, rolekit faced two serious problems:The creation of the roles were complicated and manual, requiring careful curation and attention to make sure that they continued to work from release to release of Fedora. The Cockpit Project became very popular and its limited resources became dedicated to serving the needs of their other consumers, leaving us unable to get the integration of rolekit completed.
The second of these issues remains and will likely need to be addressed, but that will be a topic for another day. The remainder of this blog entry will discuss our plans for how to improvethe creation and maintenance of roles.Ansible Galaxy Ansible Galaxy describes itself as “[Y]our hub for finding, reusing and sharing the best Ansible content”. What this means is that the Ansible project runs a public software service enabling the sharing of Github repositories containing useful Ansible roles and playbooks for deploying software services.
The Galaxy hub containsliterally thousands of pre-built server roles for Fedora, Red Hat Enterprise linux and other systems with more being added every day. With such a large community made available to us, the Server WG has decidedtoexplore the use of Ansible Galaxy as the back-end for our server role implementation, replacing rolekit’s custom (and redundant) implementation.
As part of this effort, I attended the Ansible Contributor Conference and AnsibleFest this week in Brooklyn, New York. I spent a great deal of time talking with Chris Houseknecht about ways in which we could enhance Ansible Galaxy to function for our needs.Required Galaxy Enhancements
There are a few shortcomings to Galaxy that we will need to address before we can implement a complete solution. The first of these is assurance: there is currently no way for a consumer of a role to indicate its suitability. Specifically, we will want there to be a way for Fedora to elevate a set of roles (and specific versions of those roles) to a “recommended” state. In order to do this, Galaxy will be adding support for third-party signing of role versions. Fedora will become a “signing authority” for Ansible Galaxy, indicating that certain roles and their versions should be consumed by users of Fedora.
We will also add filtering to the Galaxy API to enable clients to limit their searches to only those roles that have been signed by a particular signing authority. This will be useful for limiting the list that we expose to users in Cockpit.
The other remaining issue with Ansible is that there is currently no way to execute an Ansible script through an API; at present it must be done via execution of the Ansible CLI tool.Fedora will be collaborating with Ansible on this (see below).Required Fedora Enhancements
In Fedora, we will need to provide a useful UI for this new functionality. This will most likely need to happen in the Cockpit project, and we will have to find resources to handle this.
Specifically, we will need:UI to handle searching the Galaxy API using the role signatures and other tag filtering. UI for an “answer file” for satisfying required variables in the roles. UI for interrogating a system for what roles have been applied to it.
In addition to Cockpit UI work, we will need to provide infrastructure within the Fedora Project to provide our signatures. This will mean at minimum having secure, audited storage of our private signing key and a tool or service that performs the signing. In the short term, we can allow a set of trusted users to do this signing manually, but in the longer term we will need to focus on setting up a CI environment to enable automated testing and signing of role updates.
Lastly, as mentioned above, we will need to work on an API that Cockpit can invoke to fire off the generated Ansible playbook. This will be provided by Fedora (likely under the rolekit banner) but may be eventually absorbed into the upstream Ansible project once it matures.
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