atosclass/slalite repository overview

⁠SLALite

This project is licensed under the Apache License 2.0

⁠Rotterdam & CLASS Project

This version of the SLALite is being used in the CLASS project: https://class-project.eu/⁠

Rotterdam relies on the SLALite asset⁠ to manage the SLA Agreements generated and used in the CLASS project⁠ by other components and applicaitons. This (temp) version of the SLALite includes an adapter for Prometheus⁠ which should be merged with the original project / repository.

This version of the SLALite can be downloaded from the following URL as a docker image: https://cloud.docker.com/u/atosclass/repository/docker/atosclass/slalite⁠

⁠Environment variables

To connect this SLALite with Prometheus and Rotterdam, define the following environment variables (e.g.):

• MetricsPrometheus "go_memstats_frees_total, metric_name_2, ..."
• UrlPrometheus "http://prometheus.X.X.X.X.nip.io⁠"
• UrlRotterdam "http://rotterdam-caas.X.X.X.X.nip.io⁠"

⁠Description

The SLALite is a lightweight implementation of an SLA system, inspired by the WS-Agreement standard. Its features are:

• REST interface to manage creation and update of agreements
• Agreements evaluation on background; any breach in the agreement terms generates an SLA violation.
• Configurable monitoring: a monitoring has to be provided externally.
• Configurable repository: a memory repository (for developing purposes) and a mongodb repository are provided, but more can be added.

An agreement is represented by a simple JSON structure (see examples in resources/samples):

{
    "id": "2018-000234",
    "name": "an-agreement-name",
    "details":{
        "id": "2018-000234",
        "type": "agreement",
        "name": "an-agreement-name",
        "provider": { "id": "a-provider", "name": "A provider" },
        "client": { "id": "a-client", "name": "A client" },
        "creation": "2018-01-16T17:09:45Z",
        "expiration": "2019-01-17T17:09:45Z",
        "guarantees": [
            {
                "name": "TestGuarantee",
                "constraint": "[execution_time] < 100"
            }
        ]
    }
}

⁠Quick usage guide

⁠Installation

Build the Docker image:

make docker

Run the container:

docker run -ti -p 8090:8090 atosclass/slalite:<version>

Stop execution pressing CTRL-C

To run the service under HTTPs, you must change supply a different configuration file and the certificate files. You will find these files in docker/https for debugging purposes. DO NOT USE THE CERT.PEM and KEY.PEM in production!!

docker run -ti -p 8090:8090 -v $PWD/docker/https:/etc/slalite slalite

⁠Configuration

The SLALite can be configured with a configuration file and with environment variables. The configuration file is read by default from /etc/slalite and the current working directory. The -f parameter can be used to set the config file location.

$ ./SLALite -h
Usage of SLALite:
  -b string
        Filename (w/o extension) of config file (default "slalite")
  -d string
        Directories where to search config files (default "/etc/slalite:.")
  -f string
        Path of configuration file. Overrides -b and -d

⁠File settings

General settings

• singlefile (default: false). Sets if all file settings are read from a single file or from several files. For example, when singlefile=false, the MongoDB settings are read from the file mongodb.yml.
• repository (default: memory). Sets the repository type to use. Set this value to mongodb to use a MongoDB database.
• externalIDs (default: false). Set this to true if the repository auto assign the IDs of the saved entities.
• checkPeriod (default: 60). Sets the period in seconds of assessments executions.
• CAPath. Sets the value of a file path containing certificates of trusted CAs; to be used to connect as client to SSL servers whose certificate is not trusted by default (e.g. self-signed certificates)

REST interface settings

• port (default: 8090). Port of REST interface.
• enableSsl (default: false). Enables the use of SSL on the REST interface. The two following variables should be set.
• sslCertPath (default: cert.pem). Sets the certificate path.
• sslKeyPath (default: key.pem). Sets the private key path to access the certificate.

MongoDB settings (default file: /etc/slalite/mongodb.yml)

• connection (default: localhost). Sets the MongoDB host.
• database (default: slalite). Sets the MongoDB database name to use.
• clear_on_boot (default: false). Sets if the database is cleared on startup (useful for tests).

⁠Env vars

Every file setting can be overriden with the use of environment variables. The name of the var is the uppercase setting name prefixed with SLA_. For example, to override the check period, set the env var SLA_CHECKPERIOD.

⁠Usage

SLALite offers a usual REST API, with an endpoint on /agreements

Add an agreement:

curl -k -X POST -d @resources/samples/agreement.json https://localhost:8090/agreements

Get agreements:

curl -k https://localhost:8090/agreements
curl -k https://localhost:8090/agreements/a02

Add a template:

curl -k -X POST -d @resources/samples/template.json https://localhost:8090/templates

Get templates:

curl -k https://localhost:8090/templates
curl -k https://localhost:8090/templates/t01

Create agreement from template:

curl -k -X POST -d @resources/samples/create-agreement.json https://localhost:8090/create-agreement

{"template_id":"t01","agreement_id":"9be511e8-347f-4a40-b784-e80789e4c65b","parameters":{"M":1,"N":100,"agreementname":"An agreement name","client":{"id":"client01","name":"A name of a client"},"provider":{"id":"provider01","name":"A name of a provider"}}}

⁠LICENSE

SLALite is licensed under Apache License, version 2⁠.