SR3

sr3 Sarracenia CLI

Manual section:: 1
Date:: May 01, 2024
Version:: UNKNOWN
Manual group:: MetPX-Sarracenia

SYNOPSIS

sr3 options action [ component/config … ]

DESCRIPTION

Sr3 is a tool to manage a fleet of daemons, whose output is mostly in log files. Sr3 allows one to start, stop, and inquire the status of configured Sarracenia flows. It is the primary command line entry point to Sarracenia 3 ( https://metpx.github.io/sarracenia/ ) When sr3 is started up, it reads the entire configuration tree, and the status of all flows can be queried with, for example sr3 status. When component/config is given it is to have sr3 operate on a subset of all the configurations present.

If you already familiar in general with Sarracenia, and are looking for information about specific options or directives, best to look at sr3 Options (7)
To more easily get started, have a look at the Subscriber Guide on github
For a general guide to the interface: see the Command Line Guide

The command line has three major elements: * options * action * component/config

A flow is a group of processes running using a common component/config.

OPTIONS

Most options are stored in configuration files referred to by the component/config indicated by the listing file, but on occasion, one may wish to use command line to override values in the configuration file. Options are defined in Sr3 Options (7) Refer to that manual page for a full discussion. There is one exception:

-h (or --help)

The help option is only available on the command line. It is used to get a prompt describing the subset of options available to override config file values.

ACTIONS

The type of action to take. One of:

add: copy to the list of available configurations.

cleanup: deletes the component’s resources on the server.

convert: copy a configuration from v2 to sr3 location, updating on the way.

declare: creates the component’s resources on the server.

disable: mark a configuration as ineligible to run.

edit: modify an existing configuration.

enable: mark a configuration as eligible to run.

features: what parts of sr3 are working?

foreground: run a single instance in the foreground logging to stderr

list: list all the configurations available.

list plugins: list all the plugins available.

list examples: list all the plugins available.

remove: remove a configuration.

restart: stop and then start the configuration.

run: run as a master process (like start, but don’t return.)

sanity: looks for instances which have crashed or gotten stuck and restarts them.

show view an interpreted version of a configuration file.

start: start the configuration running

status: check if the configuration is running.

stop: stop the configuration from running

COMPONENTS

The Flow Algorithm is what is run by all sr3 processes. The flow algorithm’s behaviour is customized by options, some of which control optional modules (flowcallbacks) Each component has a different set of default option settings to cover a common use case.

cpump - copy notification messages from one pump another second one (a C implementation of shovel.)
flow - flux générique, pas de valeurs par défaut, bonne base pour la construction de flux personalisés.
poll - poll a non-sarracenia web or file server to create notification messages for processing.
post|sr3_post|sr_cpost|watch - create notification messages for files for processing.
sarra - download file from a remote server to the local one, and re-post them for others.
sender - send files from a local server to a remote one.
shovel - copy notification messages, only, not files.
watch - create notification messages for each new file that arrives in a directory, or at a set path.
winnow - copy notification messages, suppressing duplicates.

CONFIGURATIONS

When a component/configuration pair is specified on the command line, It is actually building the effective configuration from:

default.conf

admin.conf

<component>.conf (subscribe.conf, audit.conf, etc…)

<component>/<config>.conf

Settings in an individual .conf file are read in after the default.conf file, and so can override defaults. Options specified on the command line override configuration files.

While one can manage configuration files using the add, remove, list, edit, disable, and enable actions, one can also do all of the same activities manually by manipulating files in the settings directory. The configuration files for an sr3 configuration called myflow would be here:

linux: ~/.config/sarra/subscribe/myflow.conf (as per: XDG Open Directory Specication )

Windows: %AppDir%/science.gc.ca/sarra/myflow.conf , this might be: C:UserspeterAppDataLocalscience.gc.casarramyflow.conf

MAC: FIXME.

The top of the tree has ~/.config/sarra/default.conf which contains settings that are read as defaults for any component on start up. In the same directory, ~/.config/sarra/credentials.conf contains credentials (passwords) to be used by sarracenia ( CREDENTIALS for details. )

One can also set the XDG_CONFIG_HOME environment variable to override default placement, or individual configuration files can be placed in any directory and invoked with the complete path. When components are invoked, the provided file is interpreted as a file path (with a .conf suffix assumed.) If it is not found as a file path, then the component will look in the component’s config directory ( config_dir / component ) for a matching .conf file.

If it is still not found, it will look for it in the site config dir (linux: /usr/share/default/sarra/component).

Finally, if the user has set option remote_config to True and if he has configured web sites where configurations can be found (option remote_config_url), The program will try to download the named file from each site until it finds one. If successful, the file is downloaded to config_dir/Downloads and interpreted by the program from there. There is a similar process for all plugins that can be interpreted and executed within sarracenia components. Components will first look in the plugins directory in the users config tree, then in the site directory, then in the sarracenia package itself, and finally it will look remotely.

Remote Configurations

One can specify URI’s as configuration files, rather than local files. Example:

–config http://dd.weather.gc.ca/alerts/doc/cap.conf

On startup, sr3 checks if the local file cap.conf exists in the local configuration directory. If it does, then the file will be read to find a line like so:

–remote_config_url http://dd.weather.gc.ca/alerts/doc/cap.conf

In which case, it will check the remote URL and compare the modification time of the remote file against the local one. The remote file is not newer, or cannot be reached, then the component will continue with the local file.

If either the remote file is newer, or there is no local file, it will be downloaded, and the remote_config_url line will be prepended to it, so that it will continue to self-update in future.

Logs

for the logs, look in ~/.cache/sr3/logs (on linux. Other platforms, will vary.) To find them on any platform:

fractal% sr3 list
User Configurations: (from: /home/peter/.config/sr3 )
admin.conf                       credentials.conf                 default.conf
logs are in: /home/peter/.cache/sr3/log

Last line indicates the directory.

EXAMPLES

Here is a short complete example configuration file:

broker amqps://dd.weather.gc.ca/

subtopic model_gem_global.25km.grib2.#
accept .*

This above file will connect to the dd.weather.gc.ca broker, connecting as anonymous with password anonymous (defaults) to obtain notification messages about files in the http://dd.weather.gc.ca/model_gem_global/25km/grib2 directory. All files which arrive in that directory or below it will be downloaded into the current directory (or just printed to standard output if -n option was specified.)

A variety of example configuration files are available here:

https://github.com/MetPX/sarracenia/tree/main/sarra/examples