📝 — Improve documentation (fix #21)

argos/commands.py

@@ -60,13 +60,13 @@ def server():
 def agent(server_url, auth, max_tasks, wait_time, log_level):
     """Get and run tasks to the provided server. Will wait for new tasks.
 
-    Usage: argos agent https://argos.server "auth-token-here"
+    Usage: argos agent https://argos.example.org "auth-token-here"
 
     Alternatively, you can use the following environment variables to avoid passing
     arguments to the agent on the command line:
 
       \b
-      ARGOS_AGENT_SERVER_URL=https://argos.server
+      ARGOS_AGENT_SERVER_URL=https://argos.example.org
       ARGOS_AGENT_TOKEN=auth-token-here
     """
     click.echo("Starting argos agent. Will retry forever.")
@@ -83,7 +83,7 @@ def agent(server_url, auth, max_tasks, wait_time, log_level):
 @click.option("--config", default="config.yaml", help="Path the the configuration file")
 @click.option("--reload", is_flag=True, help="Enable hot reloading")
 def start(host, port, config, reload):
-    """Starts the server."""
+    """Starts the server"""
     os.environ["ARGOS_YAML_FILE"] = config
     uvicorn.run("argos.server:app", host=host, port=port, reload=reload)
 
@@ -136,7 +136,7 @@ async def cleandb(max_results, max_lock_seconds):
 @server.command()
 @coroutine
 async def reload_config():
-    """Read tasks config and add/delete tasks in database if needed"""
+    """Read tasks configuration and add/delete tasks in database if needed"""
     # The imports are made here otherwise the agent will need server configuration files.
     from argos.server import queries
     from argos.server.main import get_application, read_config

conf/systemd-agent.service

@@ -17,5 +17,5 @@ WantedBy=multi-user.target
 
 # NB: it may be better to
 # - use a dedicated user
-# - use a EnvironmentFile=/etc/default/argos-agent in order enable configuration
+# - use a EnvironmentFile=/etc/default/argos-agent in order to enable configuration
-#   changes without doing a systemctl daemon-reload
+#   changes without doing a systemctl daemon-reload

conf/systemd-server.service

@@ -8,11 +8,16 @@ PartOf=postgresql.service
 [Service]
 User=www-data
 WorkingDirectory=/var/www/argos/
+Environment="ARGOS_SERVER_WORKERS=4"
 ExecStartPre=/var/www/argos/venv/bin/argos server migrate
 ExecStartPre=/var/www/argos/venv/bin/argos server reload-config
-ExecStart=/var/www/argos/venv/bin/argos server start
+ExecStart=/var/www/argos/venv/bin/gunicorn "argos.server.main:get_application()" -w $ARGOS_SERVER_WORKERS -k uvicorn.workers.UvicornWorker
 ExecReload=/var/www/argos/venv/bin/argos server reload
 SyslogIdentifier=argos-server
 
 [Install]
 WantedBy=multi-user.target
+
+# NB: it may be better to
+# - use a EnvironmentFile=/etc/default/argos-server in order to enable configuration
+#   changes without doing a systemctl daemon-reload

docs/cli.md

@@ -40,19 +40,21 @@ Commands:
 .. ]]] -->
 
 ```man
-Usage: argos agent [OPTIONS] SERVER AUTH
+Usage: argos agent [OPTIONS] SERVER_URL AUTH
 
   Get and run tasks to the provided server. Will wait for new tasks.
 
-  Usage: argos agent https://argos.server "auth-token-here"
+  Usage: argos agent https://argos.example.org "auth-token-here"
 
   Alternatively, you can use the following environment variables to avoid
   passing arguments to the agent on the command line:
-  ARGOS_AGENT_SERVER_URL=https://argos.server     ARGOS_AGENT_TOKEN=auth-token-
+
-  here
+      ARGOS_AGENT_SERVER_URL=https://argos.example.org
+      ARGOS_AGENT_TOKEN=auth-token-here
 
 Options:
-  --max-tasks INTEGER             Number of concurrent tasks this agent can run
+  --max-tasks INTEGER             Number of concurrent tasks this agent can
+                                  run
   --wait-time INTEGER             Waiting time between two polls on the server
                                   (seconds)
   --log-level [DEBUG|INFO|WARNING|ERROR|CRITICAL]
@@ -75,8 +77,10 @@ Options:
   --help  Show this message and exit.
 
 Commands:
-  cleandb  Clean the database (to run routinely)
+  cleandb        Clean the database (to run routinely)
-  start    Starts the server.
+  migrate        Run database migrations
+  reload-config  Read tasks config and add/delete tasks in database if...
+  start          Starts the server
 ```
 
 <!--[[[end]]]
@@ -91,7 +95,7 @@ Commands:
 ```man
 Usage: argos server start [OPTIONS]
 
-  Starts the server.
+  Starts the server
 
 Options:
   --host TEXT     Host to bind
@@ -104,6 +108,26 @@ Options:
 <!--[[[end]]]
 -->
 
+### Server migrate
+
+<!--
+.. [[[ cog
+    help(["server", "migrate", "--help"])
+.. ]]] -->
+
+```man
+Usage: argos server migrate [OPTIONS]
+
+  Run database migrations
+
+Options:
+  --help  Show this message and exit.
+```
+
+<!--[[[end]]]
+-->
+
+
 ### Server clean
 <!--
 .. [[[cog
@@ -115,15 +139,36 @@ Usage: argos server cleandb [OPTIONS]
 
   Clean the database (to run routinely)
 
-  - Removes old results from the database. - Removes locks from tasks that have
+  - Removes old results from the database.
-  been locked for too long.
+  - Removes locks from tasks that have been locked for too long.
 
 Options:
-  --max-results INTEGER       Number of results per tasks to keep
+  --max-results INTEGER       Number of results per task to keep
   --max-lock-seconds INTEGER  The number of seconds after which a lock is
-                              considered stale
+                              considered stale, must be higher than 60 (the
+                              checks have a timeout value of 60 seconds)
   --help                      Show this message and exit.
 ```
 
 <!--[[[end]]]
 -->
+
+### Server reload-config
+
+<!--
+.. [[[ cog
+    help(["server", "reload-config", "--help"])
+.. ]]] -->
+
+```man
+Usage: argos server reload-config [OPTIONS]
+
+  Read tasks configuration and add/delete tasks in database if needed
+
+Options:
+  --help  Show this message and exit.
+```
+
+<!--[[[end]]]
+-->
+

docs/deployment/systemd.md

@@ -17,9 +17,3 @@ caption: /etc/systemd/system/argos-agent.service
 caption: /etc/systemd/system/argos-server.service
 ---
 ```
-
-Please note that it might be better to use Gunicorn with a Uvicorn worker, [as specified in the Uvicorn docs](https://www.uvicorn.org/#running-with-gunicorn):
-
-```bash
-gunicorn example:app -w 4 -k uvicorn.workers.UvicornWorker -b '127.0.0.1:8000'
-```

docs/developer/migrations.md

@@ -9,3 +9,5 @@ you're done, you can create a new migration.
 ```bash
 venv/bin/alembic revision --autogenerate -m "migration reason"
 ```
+
+Edit the created file to remove comments and adapt it to make sure the migration is complete (Alembic is not powerful enough to cover all the corner cases).

docs/developer/models.md

@@ -13,11 +13,12 @@ class Task {
     - selected_at
     - completed_at
     - next_run
+    - severity
+    - last_severity_update
 }
 class Result{
     - task : Task
     - task_id
-    - task
     - agent_id
     - submitted_at
     - status
@@ -27,9 +28,11 @@ class Result{
 Result "*" o-- "1" Task : has many
 ```
 
+The `severity` attribute in `Task` is the severity of the last `Result` submitted by an agent.
+
 
 ```{literalinclude} ../../argos/server/models.py
 ---
 caption: models.py
 ---
-```
+```

docs/developer/overview.md

@@ -27,3 +27,4 @@ The server acts like a job queue. When an agent asks for work, the server will:
 When it receives the results, it will:
 - Remove the "selected by" and "selected at" fields
 - Compute the next execution date.
+- Send alerts if needed

docs/developer/projects.md

@@ -10,7 +10,8 @@
 - [SQLAlchemy](https://www.sqlalchemy.org/) is the ORM we use, to connect to our database and issue queries;
 - [Alembic](https://alembic.sqlalchemy.org) is used for DB migrations;
 - [Tenacity](https://github.com/jd/tenacity) a small utility to retry a function in case an error occured;
-- [Uvicorn](https://www.uvicorn.org/) is the tool used to run our server.
+- [Uvicorn](https://www.uvicorn.org/) is the tool used to run our server;
+- [Gunicorn](https://gunicorn.org/) is the recommended WSGI HTTP server for production.
 
 ## CSS framework
 

docs/index.md

@@ -51,6 +51,12 @@ cli
 api
 ```
 
+```{toctree}
+:caption: Deployment
+:hidden:
+deployment/systemd
+```
+
 ```{toctree}
 :caption: Configuration
 :hidden:
@@ -69,9 +75,3 @@ developer/projects
 changelog
 ```
 
-```{toctree}
-:caption: Deployment
-:hidden:
-deployment/systemd
-```
-

docs/installation/getting-started.md

@@ -3,7 +3,7 @@
 ## Requirements
 
 - Python 3.11+
-- PostgreSQL 13+
+- PostgreSQL 13+ (for production)
 
 ## Getting dependencies
 
@@ -35,6 +35,8 @@ caption: .env
 ---
 ```
 
+Please note that the only supported database engines are SQLite for development and PostgreSQL for production.
+
 Then you can start the server:
 
 ```bash

docs/installation/postgresql.md

@@ -1,12 +1,12 @@
-# Installing PostgreSQL
+# Use with PostgreSQL
 
-If you intend to use argos with Postgresql, you can install it with the following commands:
+If you intend to use argos with Postgresql, which is recommended for production, you can install it with the following commands:
 
 ```bash
 pip install -e ".[postgres]"
 ```
 
-Here are a few steps for you to install postgresql on your system:
+Here are a few steps for you to install PostgreSQL on your system:
 
 ## Debian
 

pyproject.toml

@@ -30,6 +30,7 @@ dependencies = [
   "sqlalchemy-utils>=0.41,<1",
   "tenacity>=8.2,<9",
   "uvicorn>=0.23,<1",
+  "gunicorn>=21.2,<22",
 ]
 
 [project.optional-dependencies]