Pennant is a powerful dark-launch utility designed for maximum flexibility and performance.
Building and running pennant:
% brew install consul
% consul agent -dev -advertise 127.0.0.1
% git clone pennant.git
% go build && ./pennant server
{
"name": "red_button",
"description": "Makes the button on the home page red",
"default": false,
"policies": [
{
"comment": "Everybody whose username starts with 'foo'",
"rules": "user_username =~ '^foo'"
},
{
"comment": "and some volunteers",
"rules": "user_id in (10, 11, 13)"
},
{
"comment": "Also 10% of rando users",
"rules": "pct(user_username) <= 10"
}
]
}
pennant test -f tests/data/flag1.json -d tests/data/data1.json
$ pennant update -f tests/data/flag1.json
- or -
$ pennant update '{"name":"red_button","description":....}'
- or -
$ cat tests/data/flag1.json | pennant update -
Name Description DefaultValue
---------- ------------------------------------- ------------
red_button Makes the button on the home page red false
Rule Comment
------------------------ ------------------------------------------
user_username =~ '^foo' Everybody whose username starts with 'foo'
user_id in (10, 11, 13) and some volunteers
pct(user_username) <= 10 Also 10% of rando users
% pennant list
Name
----------
red_button
$ pennant show red_button
Name Description DefaultValue
---------- ------------------------------------- ------------
red_button Makes the button on the home page red false
Rule Comment
------------------------ ------------------------------------------
user_username =~ '^foo' Everybody whose username starts with 'foo'
user_id in (10, 11, 13) and some volunteers
pct(user_username) <= 10 Also 10% of rando users
$ pennant value red_button '{"user_id": 10}'
- or -
$ pennant value red_button -f document.json
- or -
$ cat document.json | pennant value red_button -
Flag Status
---------- -------
red_button enabled
$ pennant delete red_button
red_button deleted
| Method | Path | Description |
|---|---|---|
| GET | /flags | List flags |
| GET | /flags/{name} | Get a flag's definition |
| DELETE | /flags/{name} | Delete a flag |
| POST | /flags | Create or update a flag |
| GET | /flagValue/{name} | Fetch en/disabled state of a flag, given a document |
V1 milestones:
- ✓ Pluggable storage backends, ships with consul and in-memory support
- ✓ GRPC and REST query interfaces
- ✓ REST flag management interfaces
- ✓ Watches for consul value changes
- ✓ Bundled percentage calculator
- ✓ Supports arbitrary expressions for en/disabling flags
- ✓ Client and server in single binary
- Ships metrics to StatsD
- FlagGroup - evaluate multiple flags in a single query
V2:
- More drivers - redis, etcd, filesystem
- Authentication
- Prometheus compatible stats
- Query results caching, perf improvements
- GRPC flag management interface