TeleWorker - simple job worker service

• Description
• Build
• Usage

Description

TeleWorker is a job worker service solution, which includes a library for managing jobs, a server using the library and a simple CLI for the communication with the server.

❗IMPORTANT❗
It is required to start the server as sudo in order to let it manage cgroup functionality.
Otherwise tasks creation will fail with "permission denied" errors written to the task error stream.

Build

make build

Testing

Simply run

make test

Usage

Everything can be managed via the command line, no advance preparation is required.

Start a job

Starts a job, returns uuid. command flag is required. You can provide argument list separated by space at the end.

$ teleworker start -command=echo 123
$ db759134-e42e-4b39-8c88-c2359219b9ed

Optional flags are available for limiting the job resources:

• mem - memory limit in megabytes
• cpu - cpu share in percents (1-100)
• io - I/O access proportion in percents (1-100)

$ teleworker start -mem=10 -cpu=5 -command=cat "/proc/cpuinfo"
$ db759134-e42e-4b39-8c88-c2359219b9ed

For more complicated scenarios it is also possible to pipe commands. For example, you can send bash as a command and provide the list of your arguments in the end. Be aware that if your argument looks like a flag you need to provide a terminator symbol before providing arguments. See the example:

$ teleworker start -command=bash -- "-c" "cat /proc/cpuinfo | egrep '^model name' | uniq"
$ db759134-e42e-4b39-8c88-c2359219b9ed

Stop some job

Stops the job execution. The default behavior is to kill the task (SIGKILL), so you must be aware that even if the command has some clean up set on interruption request - it will be ignored.

$ teleworker stop <uuid>

Get the status of some job

Returns the status of the task, exit status (if the task is finished or terminated) and limits information (if any were wet upon the task creation).

$ teleworker status <uuid>
$ Status: ALIVE. Memory limit: 100mb.

Stream the output of some job

Gets all the logs that the task produced since the moment it was started and keeps getting new messages until either the task is finished/terminated or the execution interrupted:

$ teleworker stream <uuid>
$ ...

Optional flag err if provided will trigger the start of streaming of stderr instead of stdout.

$ teleworker stream -err <uuid>
$ ...