Deployment

Deploying the Knowledge Repo in an organization is done in two steps.

  1. A knowledge repository (or repositories) must be created. These repositories are where knowledge posts are pooled and made accessible to users.
  2. Deploy the Knowledge Repo web application on top of this repository (or repositories), which then acts as the primary gateway for users to access the stored knowledge posts.

Creating Knowledge Repositories

The Knowledge Repo project supports multiple repository backends, all offering the same programmatic API (and being subclasses of KnowledgeRepository). At this stage, two backends have been fully implemented: - GitKnowledgeRepository: A repository backed by a local git repository (optionally synced with remote git repository). - DbKnowledgeRepository: A repository backed by a database backend (most databases supported by SQLAlchemy can be used).

All backends also allow configuration using a YAML configuration file at ‘/.knowledge_repo_config.yml’ within the repository. A template for creating this file is available here, if one does not already exist or the repository configuration has grown out of sync with upstream changes.

Git Knowledge Repositories

The following command will create a new repository at <repo_path>:

$ knowledge_repo --repo <repo_path> init

The result is a git repository at <repo_path> with a .knowledge_repo_config copied from the defaults found in the repository source code. If a git repository was already found at <repo_path> it will upgrade it to be a knowledge data repository. This is useful if you are starting a repository on a remote service like GitHub, as this allows you to clone the remote repository as per normal; run this script; and then push the initialization back into the remote service using git push. Otherwise, if you plan to host this repository on a remote service like GitHub, you must push this repository to that remote service. This can be done by creating the remote repository through GitHub (or whichever service you plan to use) and then running:

$ git remote add origin <url_of_remote_repository>
$ git push -u origin master

Users can then clone this repository, and point their local knowledge_repo script at it using --repo <path_of_cloned_repository>.

Database Knowledge Repositories

Database knowledge repositories are the only backends that currently allow end-to-end publishing of knowledge posts via the web app interface. They are created on demand, where possible. Simply point the knowledge_repo script at it using something akin to --repo mysql://username:password@hostname/database:table_name. If the table does not exist it will be created if the active user has the appropriate permissions.

Note: Database Knowledge repositories also support having a .knowledge_repo_config configuration, but one is not automatically added.

Repository Configuration

As noted earlier, all knowledge repository backends support configuration via a Python file that is imported from the repository. This configuration can override the defaults in the default repository configuration found here.

This configuration file will allow you to:

  • Add postprocessors to post contributions from the repo. (see the postprocessors array of functions)
  • Add rules for which subdirectories posts can be added to. (see the path_parse() function)
  • Check and manage the format of author names at contribution time
    • Add logic to username_parse() to check post author names and raise exceptions when they don’t match
    • Add logic to username_to_name() to manage how user/author names are displayed, ex. “sally_smarts” –> “Sally Smarts”
    • Add logic to username_to_email() to manage how user/author names are matched to emails, ex. “sally_smarts” –> “sally.smarts@mycompany.com

Please refer to the default configuration file itself for further documentation.

Note

Image handling is a good example of where post-processor configuration can be very useful. Knowledge repositories’ default behavior is to add the markdown’s contents as is to your knowledge post git repository, including images. If you do not have git LFS set up, it may be in your interest to have these images hosted on some type of cloud storage, so that cloning the git repository locally is less cumbersome.

We provide an example postprocessor that adds support for pushing images to cloud storage. To use it, simply import or paste it into your .knowledge_repo_config file, and add it by name to your postprocessors configuration key.

Deploying the Web Application

Any user with access to knowledge repositories can create an instance of the Knowledge Repo Web Application that acts as a portal to them. This is achieved by running:

$ knowledge_repo --repo <repo_path> runserver

which starts a web application instance on http://127.0.0.1:7000 with the default (insecure) options. The command line also supports some high-level options, such as –port and –dburi which respectively change the local port on which the server is running, and the sqlalchemy uri where the database can be found and/or initiated.

For shared deployments, however, you will probably need to create a server configuration file. A complete server configuration template can be found here. The configuration file gives you fine-grained control over the deployment, including authentication, access policies, indexing behavior.

Once a configuration file has been created according to the documentation provided in the template, deploying the web application is as simple as:

$ knowledge_repo --repo <repo_path> deploy --config <config_file>

Supported options are –port, –dburi,`–workers`, –timeout and –config. The –config option allows you to specify a python config file from which to load the extended configuration. A template config file is provided in knowledge_repo/app/config_defaults.py. The –port and –dburi options are as before, with the –workers and –timeout options specifying the number of threads to use when serving through gunicorn, and the timeout after which the threads are presumed to have died, and will be restarted.

Database Migrations

No matter which knowledge repository backends are used, the web application itself requires a database backend in order to store its cache of the post index and user permissions. The database to be used can be specified via the CLI using the --dburi option or via the config file passed in using --config. Most datatabase backends supported by SQLAlchemy should work. Database URIs will look something like: mysql://username:password@hostname/database:table_name.

If the database does not exist, it is created (if that is possible) and initialised. When updates to the Knowledge Repo require changes to the database structure, migrations are automatically performed (unless disabled in the config to prevent accidental data loss). They can also be performed manually using:

$ knowledge_repo --repo <repo_path> db_upgrade --dburi <db>

Multiple Repositories

Multiple repositories can be stitched together into a single knowledge repository and served via a single web application instance. This is achieved using a MetaKnowledgeRepository instance, which creates a virtual filesystem into which the knowledge repositories are “mounted”.

For example, you can mount a git repostory at / and a database repository at /webposts using:

$ knowledge_repo --repo {}/path/to/git/repo --repo {webposts}<db_uri>:<table> ...

Web Editor

The web editor allows the entire post creation and publication process to be done through the web application. To enable the web editor, simply add the path(s) under which web edited posts are allowed to be created to the WEB_EDITOR_PREFIXES option in the server configuration. Note that these paths must be backed by a database repository.