2.2. Download, install and configure OnTask¶
Download or clone a copy of OnTask.
Using a command interpreter, go to the OnTask folder and locate a folder inside it with name
requirements. Verify that it contains the files
development.txt. The first file contains a list of python modules that are required by OnTask. The second is a set of additional modules to run a production instance, and the third is the same list if you intend to run a development instance.
If you plan to run a production instance of OnTask execute the command:
python3 -m pip install -r requirements/production.txt
You may need administrative privileges to execute this command.
If you plan to run a development instance of OnTask, execute the command:
python3 -m pip install -r requirements/development.txt
This command downloads a set of libraries and modules and installs them as part of the python libraries in the system.
2.2.1. OnTask Configuration¶
The next steps describe the configuration of the Django environment to run OnTask. This configuration is divided into in three groups of variables:
Environment variables (env level)
These are variables defined by the operating system and available to OnTask upon execution. The values are obtained at the start of the deployment. Changing these variables usually requires re-deploying the platform (for example if you are using a container platform like docker). These variables can only store strings.
Configuration file (conf level)
The configuration file contains a set of variable definitions that are fixed for the given platform. The values are written in a file and kept within the system file readable by the application (in the
settingsfolder). This variables can store strings, booleans, basic lists and dictionaries.
Configuration script (script level)
This is a python file that is read first by Django during its start-up procedure. The variables in this script can be defined using any python expression and may have arbitrarily complex expressions and operations (even function calls).
OnTask processes the variables in these context in the following stages:
The environment variables are loaded (if present)
The configuration file is loaded. If the file contains a definition for an environment variable, this is considered only if there is no value provided by the environment. In other words, an empty set of environment variables can be written in the configuration file and their values are considered. On the opposite side, if all environment variables are defined, any additional definition in the configuration file is ignored.
The initialization script is loaded with all the variables previously defined available.
18.104.22.168. Environment variables¶
The following variables, if defined in the environment, are considered by OnTask upon start.
Amazon Web Services access key id. This value is used when the static files in the server are served from a S3 bucket.
Amazon Web Services secret attached to the given Access Key.
Name of the S3 Bucket used to serve the static content
Path within the AWS S3 Bucket where the static files are located
Suffix that follows the host name when accessing OnTask once deployed. This is to allow OnTask to be deployed as part of a larger web server when the application is accessed as, for example,
Maximum file size for uploads
Folder in the local file system containing the OnTask plugins.
Python expression pointing to the configuration script or initial module (python file) to execute on start up. Two of these modules are provided in the folder
settings. The file
development.pyprovides definitions recommended for a development environment. The file
production.pyprovides the suggested definitions for a production deployment. Both scripts load the definitions in the module
base.py. These scripts contain configuration definitions described in Configuration script.
Host name used to serve the application.
Name for the configuration file. It must be in the folder
Official ISO 639-1 language code to use in the platform. Check the available languages in the file base.py.
Folder where to store the logs produced by the tool
logsfolder at the root of the project
URL suffix to be used by OnTask to access the media files in folder
Parameters to access the platform database: database name, username, password, host name and port respectively.
Default: All empty strings.
Step in minutes to offer when scheduling action executions
Random string of characters used to generate internal hashes. It should be kept secret. If not defined the platform will raise an error upon start.
Crontab string specifying the frequency to run the
Default ‘05 5 6 * *’
URL suffix to be used by OnTask to access the static files. This definition is ignored if
AWS_ACCESS_KEY_IDis defined as it is assumed that the static content is served through AWS. Make sure this value is not terminated by a slash.
String provided by the package
pytzto identify the time zone in which the server is running. If you want to know the name of the time zone used by your platform execute the following command:
python3 -c 'import tzlocal; print(tzlocal.get_localzone().zone)'
Remember that if any of these variables is undefined in the execution environment, they still can be defined in the configuration file.
22.214.171.124. Configuration file¶
Using a plain text editor create a file with name
local.env in folder
settings (or a file with the name assigned to the environment variable
ENV_FILENAME as described in Environment variables). Include in this file either:
the assignment of a variable from those described in Environment variables that has no environment definition, or
the assignment of any of the following variables for which you want a value different than the default.
The variables suitable to be included in the configuration file are:
Comma-separated list of host names used to validate the HTTP requests received by the platform. It helps to avoid processing requests that fake their Host headers. If OnTask is going to be hosted in
www.yoursite.com, then you may want to define it as
www.yoursite.com,yoursite.com. By default the platform allows request with any Host header.
[*](any connection from any host)
URL encoding the connection to the database. String of the format
Flag to control if the execution is in DEBUG mode.
Boolean stating if the JSON transfers should be executed when sending persnalized text.
List of URLs to access the cache service for OnTask. If there are several of these services, they can be specified as a comma-separated list such as
'rediscache://master:6379,slave1:6379,slave2:6379/1'(see Django Environ)
Boolean to control the appearance of a footer image in the home page. If true, the file
footer_image.gifis shown from the media folder.
Boolean to control if the server should use SSL for communication. There are several security features that are enabled with using SSL.
Here is an example of a minimalistic configuration file (note there is no space between variable names and the equal signs):
ALLOWED_HOSTS=HOSTNAME1,HOSTNAME2 BASE_URL='' # syntax: DATABASE_URL=postgres://username:email@example.com:5432/database DATABASE_URL=postgres://[PSQLUSERNAME]:[PSQLPWD]@127.0.0.1:5432/ontask DEBUG=False DOMAIN_NAME=[YOUR DOMAIN NAME] EXECUTE_ACTION_JSON_TRANSFER=True REDIS_URL=[YOUR REDIS URL] TIME_ZONE=[YOUR LOCAL PYTHON TIME ZONE] USE_SSL=True SECRET_KEY=[SEE BELOW]
HOSTNAME2with a comma-separated list of hostnames of the platform hosting the tool.
If OnTask is going to be served from a location different from the root of your server (for example
myhost.com/ontask, then modify the value of the variable
BASE_URLwith the suffix that should follow the domain name (in the example,
Modify the line starting with
DATABASE_URL=and change the field
[PSQLUSERNAME]with the name of the Postgresql user created in the previous step (the one that could access the ontask database and run queries). If you decided to use a different name for the database, adjust the last part of the line accordingly (replace ontask by the name of your database).
Modify the line starting with
DOMAIN_NAME=and change the field
[YOUR DOMAIN NAME] with the domain name of the machine hosting OnTask.
Replace the string
[YOUR REDIS URL]with the URL where Redis can be accessed. This is typically something similar to
[YOUR LOCAL PYTHON TIME ZONE]with the description of your time zone (see the definition of the variable
TIME_ZONEin Environment variables.
Open a command interpreter and execute the following python command:
python3 -c 'import random; import string; print("".join([random.SystemRandom().choice(string.digits + string.ascii_letters + string.punctuation) for i in range(100)]))'
Copy the long string produced as output and add it at the end of the last line of the file
local.env. It should look something like (with different content after the equal sign):
126.96.36.199. Configuration script¶
The are some additional configuration variables that directly defined in the modules
production.py in the folder
settings. Modify the python code to perform additional configuration considering:
base.pyis always executed first
The choice between
production.pyis decided based on the environment variable
DJANGO_SETTINGS_MODULEand the default value is
188.8.131.52. Log directory¶
Create a new folder with name
logs in the OnTask top folder, next to the
requirements folder, or in the location defined in the variable
LOG_FOLDER. This folder is different from the folder with the same name in the
2.2.2. OnTask Installation¶
Once you have OnTask installed and configured and the tools Redis and Postgresql running, the next steps create the documentation, initial database configuration, additional site files, and deploy. To generate the documentation go to the folder
docs_src, make sure it contains the sub-folders with names
_templates and execute the command:
make clean html copy_to_docs
The documentation is created by the application
sphinx-doc and stored in the directory
_build which is then copied to the
../docs folder. Once the documentation has been created, the next steps configure the database. If at some point during the following steps you want to reset the content of the database, run the commands
createdb explained in Install and Configure PostgreSQL. The following commands have to be execute from the project folder.
Execute the following command to create the database internal structure:
python3 manage.py migrate
A few messages should appear on the screen related to the initialization of the database.
Execute the following command to upload to the platform some initial data structures:
python3 manage.py initialize_db
The command should run without any error or exception. If you need to create additional users before deploying the platform, read the section Creating users in Bulk.
Execute the command to create a superuser account in OnTask:
python3 manage.py createsuperuser
Remember the data that you enter in this step so that you use it when you enter OnTask with your browser.
Execute the following command to collect and install the static content:
python3 manage.py collectstatic
The static files are collected from the folder in the main project older with the name stored in the variable
STATIC_URL_SUFFIXand placed, together with the static content from the folder
ontask/staticin the folder
<base_dir>/site/static. This last folder is the only one that contains all the required files to be served statically by the application. Following the suggestions given in the Django project, the content in this folder should be served directly by the web server and not through the WSGI interface. The typical approach for this is to synchronize the content of this folder with the location from where the server takes the files. Make sure you do not make any changes to the folders
<base_dir>/ontask/staticas they only contain a subset of the files.
If you are running a production instance, execute the following command to check the status of the platform:
python3 manage.py check --deploy
The command should print just one warning about the configuration variable X_FRAME_OPTIONS. If you are running a development instance, you will get various additional warning that are derived most of them from running the instance without HTTPS.
Execute the following command to start the OnTask server:
python3 manage.py runserver
If there are no errors, the message on the screen should say that your server is running in the url 127.0.0.1:8000. However, if you open your browser in that URL, an error will be shown. This error is normal and it is because the production version requires the pages to be served through SSL with a valid certificate in a conventional server.
If OnTask is going to be accessed through a web server like Apache or Nginx, stop the application and configure the web server accordingly.
If you want to use the server in development mode through the URL
127.0.0.1:8000you have to perform two more steps. First, edit the file
manage.pyand change these three lines to look like:
Second, execute the following command from the project folder:
python3 -m pip install -r requirements/development.txt
Now, the command:
python3 manage.py runserver
will start the server in the URL 127.0.0.1:8000 and you should be able to access it normally with the browser.
The development version of OnTask is not suited to be used in production because it disables several security features. Make sure you only deploy a production version.
2.2.3. Configure the Distributed Task Queue¶
There are various tasks that need to be executed by OnTask outside the web server. The solution adopted is to use Celery, Supervisor (a process control system) and Redis. Redis has been configured in a previous step. This section explains how to set up the distributed task queue and make sure it is continuously executing in parallel with the web server.
Install the application
python3 -m pip install supervisor
This application makes sure the task queue program Celery is continuously running in the background and in communication with the server.
Check that the binaries
celeryare installed in your system.
Go to the folder
supervisorin the top of the project and edit the file
The file configures
supervisordto run in the background and prepare two sets of processes for OnTask. You have two options to use this file:
Use environment variables.
The file uses internally the value of two environment variables:
PROJECT_PATH: Full path to the root of the project (the top folder containing the file
CELERY_BIN: Full path to the executable
celeryin your system (typically
Set these variables in your environment to the correct values and make sure they are properly exported and visible when running other commands. For example, in
bash, this operation would be achieve by two commands similar to:
$ export PROJECT_PATH=/full/path/to/OnTask/root/folder $ export CELERY_BIN=/full/path/to/celery/executable
Change the file
replace any appearance of the string
%(ENV_PROJECT_PATH)sby the full path to the project folder.
replace any appearance of the string
%(ENV_CELERY_BIN)sby the full path to the
Start the process control system with the command:
$ supervisord -c supervisor.conf
The command starts the process control application
supervisordwhich executes a set of process in the background.
Check that the process control system is working with the command (executed from the
$ supervisorctl -c supervisor.conf status
The output of this command should show a message similar to:
ontask-beat-celery RUNNING pid 28579, uptime 1 day, 0:07:36 ontask-celery RUNNING pid 28578, uptime 1 day, 0:07:36
If the status of the two processes is
STARTINGwait a few seconds and execute the command again. The names
ontask-celeryare the names of the two processes that OnTask uses for asynchronous task execution.
You may use this command to check if
supervisordis still running. The application is configured to write its messages to the file
celery.login the logs folder at the top of the project.
If you are upgrading OnTask from a previous version (less than 2.8), you need to edit the
crontabentry and remove the command to execute the script