tsuru-bluegreen

A blue-green deployment plugin for tsuru client

Dependencies

Python 2.7

Installation

tsuru plugin-install bluegreen https://raw.githubusercontent.com/emerleite/tsuru-bluegreen/1.4.4/src/bluegreen.py

Deployment methods

By default, the plugin deploys using git push. But if you define a deploy_dir key, inside the Application section of the configuration file, it uses tsuru app-deploy command instead.

Configuration

Tsuru bluegreen uses convention over configuration. It assumes your application backend is named using blue and green sufixes, as explained bellow:

Create a tsuru-bluegreen.ini in your application root with the following configuration:

[Application]
name: <your_app>
deploy_dir: <./build> <./build2>

[NewRelic]
api_key: <newrelic_api_key>
app_id: <newrelic_app_id>

[Grafana]
endpoint: <logstash_endpoint>
index: <logstash_index>

[WebHook]
endpoint: http://example.com
payload_extras: key1=value1&key2=value2

[Hooks]
before_pre: <command to run before 'pre' action>
after_pre: <command to run after a successful 'pre' action>
before_swap: <command to run before 'swap' action>
after_swap: <command to run after a successful 'swap' action>

[UnitsRemoval]
retry_times: 20 <how many times to retry removing a unit>
retry_sleep: 10 <how much time to wait between tries>

Note: if a NewRelic key's value is left blank, the plugin will try to get it from an environment variable (NEW_RELIC_API_KEY or NEW_RELIC_APP_ID).

'Application' section

Based on the name configuration value, you must have to have two tsuru applications and git remotes named: your_app**-blue** and your_app**-green**.

The deploy_dir configuration value is used with the --app-deploy flag. The default value is ..

'NewRelic' section

Notify New Relic about your deployment after swap. See NewRelic docs.

'Grafana' section

Notify Grafana about your deployment after swap. See Grafana docs.

'WebHook' section

POST to a WebHook after deployment swap. The payload is the defined payload_extras plus tag=<tag_value>.

'Hooks' section

Hooks are optional. They are ran before or after the corresponding actions, and everything sent to stdout and stderr is ignored. If a before hook fails (return value isn't zero), the action (pre/swap) is cancelled. If you want to run the pre/swap action independently of the before hook execution, you need to make sure it always returns 0.

Hooks must run inside a shell. If you want to run a curl command, for instance, you should do it inside a shell script:

$ cat script.sh
#! /bin/sh
curl http://example.com

$ cat tsuru-bluegreen.ini
[Application]
name: test

[Hooks]
before_pre: ./script.sh

$ tsuru bluegreen pre -t some-tag

In this case, if curl command fails, the pre action will be cancelled.

'UnitsRemoval' section

There's an issue when performing the swap of an app with multiple units. After the first unit is removed, errors are encountered when trying to remove the remaining processes.

According to tsuru contributors, this behavior is most likely do to the project's internal lock scheme.

This section defines how many times the plugin is going to retry removing a unit and how much time will it wait between tries. For example, to tell bluegreen to retry removing a unit twenty (20) times and to wait ten (10) seconds between each try, write this to you .ini fiel:

[UnitsRemoval]
retry_times: 20
retry_sleep: 10

Note: experimentation showed that small values for retry_sleep and large values for retry_times yields better usability.

Example

$ tsuru app-list

+---------------+-------------------------+---------------------------------------------------+--------+
| Application   | Units State Summary     | Address                                           | Ready? |
+---------------+-------------------------+---------------------------------------------------+--------+
| sample-blue   | 4 of 4 units in-service | sample.example.com, sample-blue.cloud.example.com | Yes    |
| sample-green  | 0 of 0 units in-service | sample-green.cloud.globoi.com                     | Yes    |
+---------------+-------------------------+---------------------------------------------------+--------+

$ git remote

sample-blue
sample-green

Usage

tsuru bluegreen --help

usage: tsuru bluegreen action [options]

Tsuru blue-green deployment (pre and live).

positional arguments:
  action                pre or swap

optional arguments:
  -h, --help            show this help message and exit
  -t [TAG], --tag [TAG] Tag to be deployed (default: master)

Tests

$ make testdeps
$ make test

Or, if you wish to use Docker;

$ make docker-test