canvasctl

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canvasctl: Controlling Canvas LMS from the command line

General Usage:

See canvasctl help or canvasctl help <command> for a list of valid commands and flags. Currently, there are commands to control aspects of the following features:

• accounts to list the accounts associated with the current user
• courses to list courses or show details about a given course
• files to upload files and show information about files in a given course
• modules to create and list modules in a course

Generally, all commands that operate on a specific course will need one of two optional parameters: -i or -n. The first requires a numeric ID identifying the course (can be obtained using canvasctl courses list), whereas the second accepts the human-readable name of the course:

$ canvasctl courses list
name=My awesome course (id=1234)
...
$ canvasctl courses show -i 1234
Course:
--------
- Name: My awesome course 
- Id: 1234
- Code: MAC
- Started: 2020-02-02 02:02:02 +0100 CET
$ canvasctl courses show -n "My awesome course"
(same output)

Note that names containing white-spaces (i.e almost all of them) will usually require shell escapes or quoting.

Note

It is entirely possible that the syntax of the command line will change slightly at this stage. Please do not rely on the syntax being stable.

The same is true for the format of the output.

Authentication

To use the tool, you need to make sure that it can authenticate towards canvas. For this, we use a canvas.conf file. This file is in TOML syntax. An example looks like this:

[Default]
URL = "https://your.canvas.url.com/"

[Sites]
[Sites.Site1]
URL = "https://your.canvas.url.com/"
Token = "enc1:salt(ElxAUE69wyMzoVR/wJxPz0iCOv1cT2eu6+/OgI5ymKs=):nonce(1mvIhV68U1bxyJxZqHDeZiTP8/wNj9Fh):qy1zwa7pJngPREGJ1/NPxU9S06sdfnOFubiiH0ujrdB+BPlpNbl8m5tcQZuOnGEQIA=="

We will get to the token shortly. The file must be in one of these locations, which are searched in order:

• $XDG_CONFIG_HOME/canvasctl (the default for XDG_CONFIG_HOME is $HOME/.config, so this is usually equivalent to the following item)
• $HOME/.config/canvasctl
• $HOME/.cavasctl While these are Unix locations, they should work on Windows with Cygwin (not tested, though).

Please note that the URLs in the above example must match. The default URL simply allows you to invoke canvasctl without having to specify the --url flag all the time. The [Sites] section is where the important authentication info is stored. It holds a URL and an token that canvasctl can use to authenticate against Canvas. These tokens are stored in an encrypted way (see below).

To get a token, go to your account's settings pane and look for "Access Tokens". You will be able to generate on. Give it an expriation date (seriously, please do), and a name that will allow you to identify it (e.g. the name of the computer) you wish to use it on.

Note: The token will only be displayed briefly, be sure to import it into canvasctl and verify that it works (as described below) before dismissing the dialog. Do not store it elsewhere, as that defeats the purpose of encrypting it. It's easy to generate a new one, so why take risks?

Now you can import the token:

$ canvasctl encrypt-token https://your.canvas.url.com/
[+] Please provide the token:
Please provide a password:
Please repeat your password:
Place this in your canvas.conf file:
Token = "enc1:salt(ElxAUE69wyMzoVR/wJxPz0iCOv1cT2eu6+/OgI5ymKs=):nonce(1mvIhV68U1bxyJxZqHDeZiTP8/wNj9Fh):qy1zwa7pJngPREGJ1/NPxU9S06sdfnOFubiiH0ujrdB+BPlpNbl8m5tcQZuOnGEQIA=="

Verify that everything works:

canvasctl courses show -i 1234
Please your decryption password:
Course:
--------
- Name: Bla bla bla
- Id: 1234
- Code: BLA
- Started: 2020-03-03 03:03:03 +0100 CET

Now you can dismiss that "new token" dialog.

Note
This is not the ideal way (in terms of user-friendlyness) of doing this. I plan on writing a keyring integration and/or using some kind of daemon to hold descrypted tokens for some configurable time in memory (think ssh-agent). I simply did not have the time yet.

Crypto
In case you were wondering:

• Argon2id for key generation with 32 byte salt (random), mem=64M, time=2
• XChaCha20 with random nonce (24 bytes, random)
• Poly1305 with authentication pass over the URL

Making the argon2id parameters depend on your machine is a useful improvement for the future.

Files

Files can be uploaded to a course using a command like this:

$ canvasctl files -i 1234 push ./file1 ./file2 ./file3
- ./file1   [OK]
- ./file2   [OK]
- ./file3   [OK]

It is possible to automatically add files to a given module:

$ canvasctl files -i 1234 push -m 'Random Variables' ./file1 ./file2 ./file3

NOTE: The module will be created, if it does not yet exist.

By default, Canvas publishes files uploaded in this way (the little green checkmark next to the file in the Canvas web UI). This means that students will be able to see the files right away. If this is not desired, --publish=false can be passed as an option:

$ canvasctl files -i 1234 push --publish=false ./file1

Finally, it is possible to set the destination path (i.e. the virtual folder inside the Canvas course, in which the file will be placed) using --path. This defaults to --path /, which is the root folder inside the course.

Quizzes

A neat feature is the ability to create quizzes from TOML files. This means that quizzes (including their answers) can be auto-generated using other means (e.g. sage math or similar) and then automatically loaded into canvas. An example of such a TOML file can be found here.

The quiz or questions descriptions may contain HTML, which is then rendered by canvas. An example can look like this

Title =  "My Quiz"
Text = "<p>This is a quiz.</p>"
Kind = "practice_quiz"
ScoringPolicy = "keep_highest"
TimeLimit = 90
AllowedAttempts = 2
ShowCorrectAnswers = true

[[Groups]]
Name= "Group 1"
PickCount = 1
Points = 1.0

[[Groups.McQuestions]]
Title = "Question 1"
Text = "<p>This is the first question. It has a pic, like so: {%mime=(image/png),filename=(./test.png),type-specific=(x=(168),y=(172))%}</p>"
Correct = "this one is correct"
Wrong = ["these", "are", "all", "false"]

Note: The TOML file currently needs to be supplied via STDIN, like so:

$ canvasctl quizzes -i 1234 create < ./examples/test.toml
# Or like this:
$ tool_that_generates_toml_quiz_on_stdout | canvasctl quizzes -i 1234 create
Creating quiz from STDIN
[+] Creating quiz: My Quiz
[+] Creating group: Group 1
 -> Creating MC question: Question 1
 -> Creating MC question: Question 2
 -> Creating multi-answer question: Question 3
[+] Creating group: Group 2
 -> Creating numeric question: Q1

Embedded file upload

It is possible to embed magic strings inside the description, as as shown in the example above:

[[Groups.McQuestions]]
Title = "Question 1"
Text = "<p>This is the first question. It has a pic, like so: {%mime=(image/png),filename=(./test.png),type-specific=(x=(168),y=(172))%}</p>"
Correct = "this one is correct"
Wrong = ["these", "are", "all", "false"]

The magic string {%mime=(image/png),filename=(./test.png),type-specific=(x=(168),y=(172))%} tells canvasctl to look for a file test.png relative to the current working directory. It also informs canvasctl that this is a png file, which enables further features. In this case, it enables us to specify the dimensions the picture should have when displayed to students via HTML. The result will be that canvasctl uploads this picture, retrieves the file id, and then replaces the magic above by an HTML tag like the following before uploading.

<img src="/courses/123/files/456/preview" alt="test.png" width="168" height="172" />`

The upshot is that the question displays test.png with the given dimensions at the location of the magic string inside the HTML description.

Other mime-types are supported. However, currently they all result in a simple upload with the magic string being replaced by an HTML link. This is useful for additional files that need to be accessed as part of the question.

Finally, the target folder on canvas can also be specified: {%mime=(image/png),filename=(./test.png),folder=(/lecture12),type-specific=(x=(168),y=(172))%} which results in the file appearing in folder lecture12 within the target course on canvas. The folder is created, if it does not exist.

Known deficiencies

• Not all question types are supported. More will be added eventually. Currently supported:

  • Numeric questions (answers can be given as range, as value + epsilon (float64), or as integer + precision)
  • Multiple choice questions (precisely one answer is correct)
  • Multiple answer questions (n out of m answers are correct)
  • Multiple blank questions
  • True/False questions
  • Exact answer questions
  • File upload questions
  • Essay questions

• Currently questions must be in a question-group, because this will allow canvas to select questions at random from those groups.

  If a single fixed question is needed, a group containing just one question is currently the only way to achieve that goal.

Documentation

Overview

canvasctl: Use Canvas LMS from command line

Copyright (C) 2020 Marcus Gelderie

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.