playlabs 0.5.2.dev13

The obscene ansible paas distribution

Playlabs combines simple ansible patterns with packaged roles to create a docker orchestrated paas to prototype products for development to production.

Playlabs does not deal with HA, for HA you will need to do the ansible plugins yourself, or use kubernetes … but Playlabs will do everything else, even configure your own sentry or kubernetes servers !

DISCLAMER: maybe it even works for you, but that’s far from garanteed so far.

Install playlabs

Install with:

pip3 install --user -e git+https://yourlabs.io/oss/playlabs#egg=playlabs

Run the ansible-playbook wrapper command without argument to see the quick getting started commands:

~/.local/bin/playlabs

Quick start

You have a new host and you need your user to be installed with your public key, passwordless sudo, and secure SSH. The first command to run on a new host is playlabs init, ie.:

playlabs init root@1.2.3.4

# all options are ansible options are proxied
playlabs init @somehost --ask-become-pass

# example with a typical openstack vm
playlabs init ubuntu@somehost --ask-become-pass

Now your user can install roles:

playlabs install ssh,docker,firewall,nginx @somehost

And deploy a project, examples:

playlabs @somehost deploy image=betagouv/mrs:master
playlabs @somehost deploy
    image=betagouv/mrs:master
    plugins=postgres,django,uwsgi
    backup_password=foo
    prefix=ybs
    instance=hack
    env.SECRET_KEY=itsnotasecret
playlabs @somehost deploy
    prefix=testenv
    instance=$CI_BRANCH
    image=$CI_REGISTRY_IMAGE:$CI_COMMIT_SHA

If you have that work, creating an inventory is the way to move on, wether you want to version configuration, add a deploy user for your CI, configure a secret backup password, add ssh-keys …:

playlabs scaffold ./your-inventory

Read on this README for gory details if you are already an Ansible user and only need to know about the patterns we’re using playlabs for.

A more extensive and user-friendly documentation is in the docs sub-directory of playlabs and online @ https://playlabs.rtfd.io thanks to RTFD :)

0. Init

Initializing means going from a naked system to a system with your own user, ssh key, dotfiles, sudo access, secure sshd, and all necessary dependencies to execute ansible, such as python3. It will also install your friend account if you have an ansible inventory repository where you store your friend list in yml.

You might need to pass extra options to ansible in some cases, for example if your install provides a passworded sudo, add --ask-sudo-pass or put the password in the CLI, since initializing will remove

playlabs init @somehost
playlabs init user:pass@somehost
playlabs init user@somehost --ask-sudo-pass
playlabs init root@somehost

1. Roles

If you want to deploy your project, then you need to install the paas which consists of three roles: docker, firewall, and nginx. The nginx role sets up two containers, nginx-proxy that watches the docker socket and introspects docker container environment variables, such as VIRTUAL_HOST, to reconfigure itself, it even supports uWSGI. The other container is nginx-letsencrypt, that shares a cert volume with the nginx-proxy container, and watches the docker socket for containers and introspect variables such as LETSENCRYPT_EMAIL, to configure the certificates.

Remember the architecture:

• nginx-proxy container recieves requests,

• nginx-letsencrypt container generates certificates,

• other docker containers have environment variables necessary for the above

The CLI itself is pretty straightforward:

playlabs install docker,firewall,nginx @somehost # the paas for the project role
playbabs install sendmail,netdata,mailcatcher,gitlab @staging
playbabs install sendmail,netdata,sentry user@production

The difference between traditionnal roles and playlabs roles, is that in playlabs they strive to have stuff running inside docker to leverage the architecture of the nginx proxy.

Playlabs can configure sendmail of course, but also has roles providing full-featured docker based mailservers or mailcatcher instances for your dev, training or staging environments for example.

This approach comes from migrating away from “building in production” to “building immutable tested chroots”, away from “pet” to “cattle”.

But if you’re already an ansible hacker you’re better off with ansible to do a lot more than than what docker-compose has to offer, such as managing users and roles, on your SDN as in your apps.

In fact, you will see role that consist of a single docker ansible module call, but the thing is that you can spawn it in one command and have it integrated with the rest of your server, and even rely on ansible to provision fine-grained RBAC in your own apps.

2. Project: deployments

The project role is made to be generic and cover infrastructure needs to develop a project, from development to production. Spawn an environment, here with an example image this repo is tested against:

playlabs @yourhost deploy betagouv/mrs:master '{"env":{"SECRET_KEY" :"itsnotasecret"}}'

It will use the IP address by default if ansible finds it, set the dns with the dns option dns=yourdns.com, or set it in project_staging_dns yaml variable of your-inventory/group_vars/all/project.yml.

This is because the default prefix is project and the default instance is staging. Let’s learn a new way of specifiying variables, add to your variables:

yourproject_production_image: yourimage:production
yourproject_production_env:
  SECRET_KEY: itsnotsecret
  # the above value could be encrypted with ansible-vault s_encrypt

Then you can deploy as such:

playlabs @yourhost deploy prefix=yourproject instance=production

If you configure yourhost in your inventory, in group “yourproject-production”, then you don’t have to specify the host anymore:

playlabs @yourhost project prefix=$CI_PROJECT instance=$CI_BRANCH

3. Project: plugins

PostgreSQL or Django or uWSGI support are provided through project plugins, which you may activate as such:

• specify -p postgres,uwsgi,django

• configure yourprefix_yourinstance_plugins=[postgres, uwsgi, django]

• add to Dockerfile ENV PLAYLABS_PLUGINS postgres,uwsgi,django

The order of plugins matters, having postgres first ensures postgres is started before the project image.

Plugins are directories located at the root of playlabs repo, but at some point we can imagine loading them from the image itself.

Plugins contain the following:

• vars.yml: variables that are auto-loaded

• deploy.pre.yml: tasks to execute before deploy of the project image

• deploy.post.yml: tasks to execute after deploy of the project image

• backup.pre.sh: included in backup.sh template before the backup

• backup.post.sh: included in backup.sh template before the backup

• restore.pre.sh: included in restore.sh template before the restore

• restore.post.sh: included in restore.sh template before the restore

5. Inventory (git versioning of cfg)

Most roles require an inventory to be really fun. Initiate an empty repository where you will store your data that the roles should use:

playlabs scaffold your-inventory

In inventory.yml you can define your machines as well as the roles they should be included by default in when playing a role without a specific target:

all:
  hosts:
    yourhost.com:
    otherhost:
      fqdn: yourdomain.tld
      ansible_ssh_port: 22
      ansible_ssh_host: 123.12.12.23

children:
  netdata:
    hosts:
      yourhost

In the above you have created a netdata group with a host yourhost. Executing the netdata role without explicit @ target will automacitally install netdata on yourhost thanks to that.

Given how free ansible limit syntax lets us, we can use rich notations such as this one to add two hosts to two roles at once:

children:
  netdata-mailcatcher:
    hosts: [yourhost.com, otherhost]

You can add as much metadata as you want in group_vars, for now let’s add some users to your-inventory/group_vars/all/users.yml:

---
users:
- name: jl
  first_name: John  # used by django role for example
  email: [e-mail]
  roles:
    ssh: sudo
    k8s: cluster-admin
    sentry: superuser

Be carefull that roles for a user are a 2d matrix: each key or value may correspond to an ansible role name, the other is the level of user within that role, that’s why roles is a key value pair.

Every time you init a machine from a directory that is an inventory, it will install all users.

Options

Ansible

Some of the variables you can like

-e key=value                    # set variable "key" to "value"
-e '{"key":"value"}'            # same in json
-i path/to/inventory_script.ext # load any numbers of inventory variables
-i 1.2.4.4,                     # add a host by ip to this play
--limit 1.2.4.4,                # limit play execution to these hosts
--user your-other-user          # specify a particular username
--noroot                        # don't try becoming root automatically

Global variables

Variables that are used by convention accross roles:

letsencrypt_uri=https...
letsencrypt_email=your@...

Role variables

Base variable are defined in playlabs/roles/rolename/vars/main.yml and start with the rolename_, they can be overridden in your inventory’s group_vars/all/rolename.yml.

The base variable will default to the same variable without the rolename_ prefix:

# Set project_image project role variable from the command line
image=your/image:tag

Role structure

Default roles live in playlabs/roles and share the standard directory structure with ansible roles, that you can scaffold with the ansible-galaxy tool.

Playlabs use roles as alternatives as docker-compose when possible, rather than polluting the host with many services.

Project variables

The project role base variables calculate to be overridable by prefix/instance:

# project_{image,*} base value references project_staging_{image,*} from inventory
instance=staging

# project_{image,*} base value references mrs_production_{image,*} from inventory
instance=production prefix=mrs

Project plugins variable

The project role has a special plugins variable that can be overridden in the usual way, but it will also try to find it by introspecting the docker image for the PLAYLABS_PLUGINS env var ie:

ENV PLAYLABS_PLUGINS postgres,django,uwsgi,sentry

Plugin variables

Plugin variables are loaded by the project role for each plugin that it loads if any.

Base plugin variables start with project_pluginname_ and the special project_pluginname_env variable should be a dict, they will be all merged to add environment variables to the project container, project_env will be a merge of all them plugin envs.

Plugin env vars should preferably use overridable variables.

Plugin structure

Default plugins live in playlabs/plugins and have the following files:

• backup.pre.sh take files out of containers and add them to the $backup variable

• backup.post.sh clean up files you have taken out after the backup has been done

• restore.pre.sh clear the place where you want to extract data from the restic backup repository

• restore.post.sh load new data and clean after the project was restarted in the snapshot version,

• deploy.pre.yml ansible tasks to execute before project deployment, ie. spawn postgres

• deploy.post.yml ansible tasks to execute after project deployment, ie. create users from inventory

• vars.yml plugin variables declaration

Operations

By default, it happens in /home/yourprefix-yourinstance. Contents depend on the activated plugins.

In the /home/ directory of the role or project there are scripts:

• docker-run.sh standalone command to start the project container, feel free to have on that one

• backup.sh cause a secure backup, upload with lftp if inventory defines dsn

• restore.sh recovers the secure backup repository with lftp if inventory desfines dsn. Without argument` list snapshots. With a snapshot argument` proceed to a restore of that snapshot including project image version and plugin data

• prune.sh removes un-needed old backup snapshots

• log logs that playlabs rotates for you, just fill in log files, it will do a copy truncate though, but works until you need prometheus or something

For backups to enable, you need to set backup_password, either with -e, either through yourpefix_yourinstance_backup_password.

The restic repository is encrypted, if you set the lftp_dsn or yourprefix_yourinstance_lftp_dsn then it will use lftp to mirror them. If you trash the local restic repository, and run restore.sh, then it will fetch the repository with lftp.