Files
fn-serverless/docs/operating/options.md
Tolga Ceylan c848fc6181 fn: hot container timer improvements (#751)
* fn: hot container timer improvements

With this change, now we are allocating the timers
when the container starts and managing them via
stop/clear as needed, which should not only be more
efficient, but also easier to follow.

For example, previously, if eject time out was
set to 10 secs, this could have delayed idle timeout
up to 10 secs as well. It is also not necessary to do
any math for elapsed time.

Now consumers avoid any requeuing when startDequeuer() is cancelled.
This was triggering additional dequeue/requeue causing
containers to wake up spuriously. Also in startDequeuer(),
we no longer remove the item from the actual queue and
leave this to acquire/eject, which side steps issues related
with item landing in the channel, not consumed, etc.
2018-02-12 14:12:03 -08:00

3.8 KiB

Fn Runtime Options

Default run command for production

This will run with docker in docker.

docker run --privileged --rm --name fns -it -v $PWD/data:/app/data -p 80:8080 fnproject/fnserver

See below for starting without docker in docker.

Configuration

When starting Fn, you can pass in the following configuration variables as environment variables. Use -e VAR_NAME=VALUE in docker run. For example:

docker run -e VAR_NAME=VALUE ...
Env Variables Description Default values
FN_DB_URL The database URL to use in URL format. See Databases for more information. sqlite3:///app/data/fn.db
FN_MQ_URL The message queue to use in URL format. See Message Queues for more information. bolt:///app/data/worker_mq.db
FN_API_URL The primary Fn API URL to that this instance will talk to. In a production environment, this would be your load balancer URL. N/A
FN_PORT Sets the port to run on 8080
FN_LOG_LEVEL Set to DEBUG to enable debugging INFO
FN_LOG_DEST Set a url to send logs to, instead of stderr. [scheme://][host][:port][/path]; default scheme to udp:// if none given, possible schemes: { udp, tcp, file }
FN_LOG_PREFIX If supplying a syslog url in FN_LOG_DEST, a prefix to add to each log line
FN_API_CORS A comma separated list of URLs to enable CORS for (or * for all domains). This corresponds to the allowed origins in the Acccess-Control-Allow-Origin header. None
FN_FREEZE_IDLE_MSECS Set this option to specify the amount of time to wait in milliseconds before pausing/freezing an idle hot container. Set to 0 to freeze idle containers without any delay. Set to negative integer to disable freeze/pause of idle hot containers. 50
FN_EJECT_IDLE_MSECS Set this option to specify the amount of time in milliseconds to periodically check to terminate an idle hot container if the system is starved for CPU and Memory resources. Set to negative integer to disable this feature. 1000
DOCKER_HOST Docker remote API URL. /var/run/docker.sock
DOCKER_API_VERSION Docker remote API version. 1.24
DOCKER_TLS_VERIFY Set this option to enable/disable Docker remote API over TLS/SSL. 0
DOCKER_CERT_PATH Set this option to specify where CA cert placeholder. ~/.docker/cert.pem

Starting without Docker in Docker

The default way to run Fn, as it is in the Quickstart guide, is to use docker-in-docker (dind). There are a couple reasons why we did it this way:

  • It's clean. Once the container exits, there is nothing left behind including all the function images.
  • You can set resource restrictions for the entire Fn instance. For instance, you can set --memory on the docker run command to set the max memory for the Fn instance AND all of the functions it's running.

There are some reasons you may not want to use dind, such as using the image cache during testing or you're running Windows.

Mount the Host Docker

One way is to mount the host Docker. Everything is essentially the same except you add a -v flag:

docker run --rm --name functions -it -v /var/run/docker.sock:/var/run/docker.sock -v $PWD/data:/app/data -p 8080:8080 fnproject/fnserver

On Linux systems where SELinux is enabled and set to "Enforcing", SELinux will stop the container from accessing the host docker and the local directory mounted as a volume, so this method cannot be used unless security restrictions are disabled.

Run outside Docker

You can of course just run the binary directly, you'll just have to change how you set the environment variables above.

See contributing doc for information on how to build and run.