Cavia

Remote resource management for Clojure projects.

Rationale

In some cases, tests of a project require large-size files. Among other things, codes for parsing and I/O should be tested by various kinds of files. But generally, SCM is not good for controlling such large test files. One of the solutions is using other tools like git-annex or Git LFS. Some Clojurians, however, may think that they want to solve it in the Clojure ecosystem.

Cavia is useful for such developers. Cavia is written in Clojure so that it can be directly used in a project and source codes. Cavia downloads test resources from remotes, checks their hash before tests, and provides convenience functions to access the resources.

Installation

Cavia is available as a Maven artifact from Clojars.

Clojure CLI/deps.edn:

cavia/cavia {:mvn/version "0.6.2"}

Leiningen/Boot:

[cavia "0.6.2"]

Basic usage

Define resources profile

First, load cavia.core and prepare resources' information with defprofile macro.

(require '[cavia.core :as cavia :refer [defprofile]])

(defprofile prof
  {:resources [;; Simple HTTP
               {:id :resource1
                :url "http://example.com/resource1"
                :sha256 "0123456789abcdef01234567890abcdef01234567890abcdef01234567890abc"}

               ;; Basic authorization
               {:id :resource2
                :url "http://example.com/resource2"
                :sha1 "123456789abcdef01234567890abcdef01234567"
                :auth {:type :basic, :user "user", :password "password"}}

               ;; FTP
               {:id :resource3
                :url "ftp://example.com/resource3"
                :sha256 "23456789abcdef01234567890abcdef01234567890abcdef01234567890abcde"
                :auth {:user "user", :password "password"}}

               ;; S3
               {:id :resource4
                :url "https://bucket-name.s3.region.amazonaws.com/resource4"
                :sha1 "3456789abcdef01234567890abcdef0123456789"
                :protocol :s3
                :auth {:access-key-id "accesskey", :secret-access-key "secretkey"}}

               ;; Compressed resource
               {:id :resource5
                :url "http://example.com/resource5.gz"
                :sha1 "456789abcdef01234567890abcdef0123456789a"
                :packed :gzip}]
   :download-to ".cavia"})

Resources are defined in :resources as a vector including some maps. Each resource map must have :id :url :md5/:sha1/:sha256 fields, which are mandatory. :id should be specified as keyword or string, which is used for resource access and downloading file name.

MD5, SHA1, and SHA256 are supported as hash algorithms for verifying files. One algorithm must be specified at least. If more than one algorithm are specified, a stronger algorithm will be used: MD5 < SHA1 < SHA256.

:auth field is optional. It can be used for password authentication. Cavia is now supporting HTTP/HTTPS/FTP/FTPS/S3 protocols and Basic/Digest/OAuth2 authentications. A resource that :packed specified will be uncompressed after downloading. Only gzip (:gzip) format is supported.

Cavia downloads resources to :download-to directory. The default location is ./.cavia. Thus maybe you should add /.cavia to your SCM ignore list.

Resource management

Cavia provides some functions for managing resources.

(cavia/get! prof)   ; downloads missing resources

(cavia/verify prof) ; checks the downloaded resources' hash

(cavia/clean! prof) ; removes the download directory

To call Cavia functions without the profile specification, use with-profile macro.

(with-profile prof
  (cavia/clean!)
  (cavia/get!))

get! and other functions output progress and logs' print to stdout. To call the above functions quietly, use without-print macro.

(without-print
  (cavia/get! prof))

Resource access

You do not need to remember the downloaded resources' paths any more. resource returns the absolute path to the resource from the specified resource id. It returns nil when the id is not defined.

(cavia/resource prof :resource1)
;;=> "/home/totakke/cavia-example/.cavia/resource1"

(cavia/resource prof :undefined)
;;=> nil

Integration with test frameworks

Cavia is a library for management of test resources. It is good to use Cavia with test frameworks like clojure.test, Midje, etc.

with clojure.test

(ns foo.core-test
  (:require [clojure.test :refer :all]
            [cavia.core :as cavia :refer [defprofile]]))

(defprofile prof
  {:resources [{:id :resource1
                :url "http://example.com/resource1"
                :sha256 "0123456789abcdef01234567890abcdef01234567890abcdef01234567890abc"}]})

(defn fixture-cavia [f]
  (cavia/get! prof)
  (f))

(use-fixtures :once fixture-cavia)

(deftest your-test
  (testing "tests with the cavia's resource"
    (is (= (slurp (cavia/resource prof :resource1)) "resource1's content")))

with Midje

(ns foo.t-core
  (:require [midje.sweet :refer :all]
            [cavia.core :as cavia :refer [defprofile with-profile]]))

(defprofile prof
  {:resources [{:id :resource1
                :url "http://example.com/resource1"
                :sha256 "0123456789abcdef01234567890abcdef01234567890abcdef01234567890abc"}]})

(with-profile prof

  (with-state-changes [(before :facts (cavia/get!))]
    (fact "tests for a large file" :slow
      (slurp (cavia/resource :resource1) => "resource1's content")))

  )

Use as a simple downloader

Cavia provides features of file downloading as independent functions.

(require '[cavia.downloader as dl])

(dl/http-download! "http://example.com/foobar.txt" "path/to/foobar.txt")

HTTP/HTTPS, FTP/FTPS, and S3 downloading functions support a resume option. If you specify :resume true, the functions resume downloading a partially downloaded file.

(dl/s3-download! "https://foo.s3.region.amazonaws.com/bar/foobar.txt"
                 "path/to/foobar.txt"
                 {:access-key-id "accesskey", :secret-access-key "secretkey"}
                 :resume true)

License

Copyright © 2014-2022 Toshiki Takeuchi

Distributed under the Eclipse Public License version 1.0.