Files
fn-serverless/docs/operating/options.md
Tolga Ceylan 5dc5740a54 fn: runner status and docker load images (#1116)
* fn: runner status and docker load images

Introducing a function run for pure runner Status
calls. Previously, Status gRPC calls returned active
inflight request counts with the purpose of a simple
health checker. However this is not sufficient since
it does not show if agent or docker is healthy. With
this change, if pure runner is configured with a status
image, that image is executed through docker. The
call uses zero memory/cpu/tmpsize settings to ensure
resource tracker does not block it.

However, operators might not always have a docker
repository accessible/available for status image. Or
operators might not want the status to go over the
network. To allow such cases, and in general possibly
caching docker images, added a new environment variable
FN_DOCKER_LOAD_FILE. If this is set, fn-agent during
startup will load these images that were previously
saved with 'docker save' into docker.
2018-07-12 13:58:38 -07:00

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Markdown

# Fn Runtime Options
## Default run command for production
This will run with docker in docker.
```sh
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:
```sh
docker run -e VAR_NAME=VALUE ...
```
| Env Variables | Description | Default values |
| --------------|-------------|----------------|
| `FN_DB_URL` | The database URL to use in URL format. See [Databases](databases/README.md) for more information. | sqlite3:///app/data/fn.db |
| `FN_MQ_URL` | The message queue to use in URL format. See [Message Queues](mqs/README.md) 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_ORIGINS` | A comma separated list of URLs to enable [CORS](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS) for (or `*` for all domains). This corresponds to the allowed origins in the `Acccess-Control-Allow-Origin` header. | None |
| `FN_API_CORS_HEADERS` | A comma separated list of Headers to enable [CORS](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS) for. This corresponds to the allowed headers in the `Access-Control-Allow-Headers` header. | Origin,Content-Length,Content-Type |
| `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 |
| `FN_MAX_RESPONSE_SIZE` | Set this option to specify the http body or json response size in bytes from the containers. | 0 (off) |
| `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 |
| `FN_MAX_FS_SIZE_MB` | Set this option in MB to pass a `size` option to Docker storage driver. This limits the file system size for all containers on the system. See [Docker storage driver options per container](https://docs.docker.com/engine/reference/commandline/run/#set-storage-driver-options-per-container) documentation for details. | None |
| `FN_DOCKER_NETWORKS` | Set this option with a list of docker networks for function containers to use. If unset, default docker network is used. | None |
| `FN_DISABLE_READONLY_ROOTFS` | Set this option to enable writable root filesystem. By default root filesystem is mounted read-only. | None |
| `FN_DOCKER_LOAD_FILE` | Set this option with an absolute path to a tarball to load a set of docker images during fn server startup. The tarball can be generated using [docker save](https://docs.docker.com/engine/reference/commandline/save/). | None |
## 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](windows.md).
### Mount the Host Docker
One way is to mount the host Docker. Everything is essentially the same except you add a `-v` flag:
```sh
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](../CONTRIBUTING.md) for information on how to build and run.