runner

Runner

runner is a structured command executer for Unix systems that monitor file changes to trigger process restarts.

Create a file name Procfile in the root of the project you want to run, and add the following content:

workdir: $GOPATH/src/github.com/example/go-app
formation: web web-a web-b db optional-service=0
observe: *.go *.js
ignore: /vendor
build-server: make server
web: restart=fail waitfor=localhost:8888 ./server serve
web-a: restart=onbuild waitfor=localhost:8888 ./server serve alpha
web-b: restart=onbuild waitfor=localhost:8888 ./server serve bravo
db: restart=failure waitfor=web ./server db
optional-service: ./optional-service

Special process type names:

• workdir: the working directory. Environment variables are expanded. It follows the same rules for exec.Command.Dir.

• baseport: when set to a number, it will be used as the starting point for the $PORT environment variable. Each process type will have its own exclusive $PORT variable value.

• observe: a space separated list of file patterns to scan for. It uses filepath.Match internally. File patterns preceded with exclamation mark (!) will not trigger builds.

• ignore: a space separated list of ignored directories relative to workdir, typically vendor directories.

• formation: allows to control how many instances of a process type are started, format: procTypeA:# procTypeB:# ... procTypeN:#. If procType is absent, it is not started. Empty formations start one of each process.

• build*: process type name prefixed by "build" are always executed first and in order of declaration. On failure, they halt the initialization.

• waitfor (in process type): target hostname and port that the runner will probe before starting the process type.

• restart (in process type): "onbuild" will restart the process type at every build; "fail" will restart the process type on failure; "loop" restart the process when it naturally terminates; "temporary" runs the process only once.

• signal (in process types): "SIGTERM", "term", or "15" terminates the process; "SIGKILL", "kill", or "9" kills the process. The default is "SIGKILL".

• timeout (in process types): duration (in Go format) to wait after sending the signal to the process.

CLI parameters

NAME:
   runner - simple Procfile runner

USAGE:
   runner [global options] command [command options] [arguments...]

VERSION:
   v2 (4207c79dde9478596d3af8e055f00201cc7ddfec)

COMMANDS:
   logs     Follows logs from running processes
   help, h  Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --port value                                         base IP port used to set $PORT for each process type. Should be multiple of 1000. (default: 0)
   --service-discovery value                            service discovery address (default: "localhost:64000")
   --formation procTypeA:# procTypeB:# ... procTypeN:#  formation allows to control how many instances of a process type are started, format: procTypeA:# procTypeB:# ... procTypeN:#. If `procType` is absent, it is not started. Empty formations start one of each process.
   --env file                                           environment file to be loaded for all processes, if the file is absent, then this parameter is ignored. (default: ".env")
   --skip procTypeA procTypeB procTypeN                 does not run some of the process types, format: procTypeA procTypeB procTypeN
   --only procTypeA procTypeB procTypeN                 only runs some of the process types, format: procTypeA procTypeB procTypeN
   --optional procTypeA procTypeB procTypeN             forcefully runs some of the process types, format: procTypeA procTypeB procTypeN
   --help, -h                                           show help
   --version, -v                                        print the version

-env file loads the environment file common to all process types. It must be in the format below:

VARIABLENAME=VALUE
VARIABLENAME=VALUE

Note: one environment variable per line.

--formation procTypeA:# procTypeB:# ... procTypeN:# allows to control how many instances of a process type are started, format: procTypeA:# procTypeB:# ... procTypeN:#. If procType is absent, it is not started. Empty formations start one of each process.

-port PORT is the base IP port number used for each process type. It passes the port number as an environment variable named $PORT to the process, and it can be used as means to facilitate the application start up.

Environment variables available to processes

Each process will have three environment variables available.

PS is the name which the runner has christened the process.

PORT is the IP port which the runner has indicated to that instance of a service to bind itself to.

DISCOVERY is the HTTP service that returns a JSON describing each process type port. This assumes the process has honored the PORT variable and bound itself to the configured one.

Service discovery by environment variable

Additionally to the basic three variables above, the runner will add another one for each instance of a process type, like what follows:

# format: NAME_#_PORT
formation: web:3 worker:2
web: server back
worker: some-worker

# Extra vars injected for both web.* and worker.*
# WEB_0_PORT=localhost:5000
# WEB_1_PORT=localhost:5001
# WEB_2_PORT=localhost:5002
# WORKER_0_PORT=localhost:5100
# WORKER_1_PORT=localhost:5101

These variable names are compliant with the POSIX standards on shells section of IEEE Std 1003.1-2008 / IEEE POSIX P1003.2/ISO 9945.2 Shell and Tools. Non-compliant chars are replaced with an underscore (_) and name uniqueness is enforced.

Installation

go get cirello.io/runner/v2

https://pkg.go.dev/cirello.io/runner/v2