Maintaining a traditional CLI program for a web service can be
difficult, since any new CLI features are not available to users
unless the user updates their CLI program. That defeats some of
the advantages of using a web service to being with, where new
features are immediately available for users to use when they
are deployed.
To avoid this issue, this uses an approach I'm dubbing thin-CLI,
where the CLI program is as a thin as possible. With thin-CLI,
the CLI submits the argv to the web service, and the web service
parses the argv and takes appropriate action. This allows the
CLI to support most new features as soon as they are deployed,
without the user having to update the CLI program.
Here's a breakdown of the parts:
* bin/ubi: The CLI program that users will run. This will
eventually be written in a cross-compiliable language, but
for now it is prototyped in Ruby. This submits the argv
to the server (thin-CLI approach), and depending on the
response, prints to stdout (success) or stderr (error).
It has support for executing ssh or psql, but to limit
potential issues with a adverse server, only a single
command line argument is provided by the server. The
allowed commands are fixed by the client (currently only
ssh and psql are allowed commands). At this prototype
stage, configuration of bin/ubid is done via environment
variables. You must provide the UBI_TOKEN environment
variable, and some other UBI_* environment variables can
be set. bin/ubi will read .env.rb if it exists, so you
can put the token into there. bin/ubi currently defaults
to http://api.localhost:9292/cli as the address (puma
running in development locally).
* routes/cli.rb: Clover route file, only allowed for api
requests, which passes the argv to UbiCli.
* lib/ubi_cli.rb: Adds UbiCli, which is used as the scope
class when executing the command blocks for CLI commands.
Passes the argv to UbiRodish to do the parsing, providing
the instance of UbiCli as the context object. This class
has instance methods that issue internal requests to
Clover's API. It currently takes the JSON responses from
Clover's API, and turns them into plain-text responses,
which will be provided to the client (bin/ubi), which will
just take the response output and print to stdout/stderr.
This currently contains code not currently used, but will
be used by future commits.
* lib/ubi_rodish.rb: Rodish processor. In this initial
commit, only provides --help and --verbose options, and
no subcommands.
This has one small change to the create_vm spec method,
allowing you to pass an existing project_id keyword, to use
that project instead of creating a new project.
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