revolver

A simple reloader tool written in Go.

Build

go build ./cmd/revolver

Test

go test ./...

Usage

When starting revolver it looks for a file called revolver.yml in the current directory. This is a simple yaml file with the configuration parameters for running revolver. The revolver.yml file can be checked into version control repositories.

A full featured sample revolver.yml file looks like the following:

dir: "."
excludeDir: [".git", "other"]
interval: 1s
action:
  - name: "build"
    pattern: ["**/*.go", "**/*.yml"]
    exclude: ["exclude", "**/exclude*"]
    build: ["build cmd 1", "build cmd 2"]
    run: "run cmd"
  - name: "test"
    pattern: ["**/*_test.go", "**/.*"]
    build: ["build cmd 1", "build cmd 2"]

The configuration file aims to be quite flexible.

If a string array type contains only one element, it can be written as a simple string value:

dir: "."
excludeDir: ".git"
interval: 1s
action:
  - name: "build"
    pattern: "**/*.go"
    exclude: "exclude"
    build: "build cmd 1"
    run: "run cmd"
  - name: "test"
    pattern: "**/*_test.go"
    build: "build cmd 1"

You can omit most of the parameters, the only requirement is to have at least one action with a build or run command:

action:
  - build: ["go install"]

If only one action is needed, the action list can be omited and the values can be written in the top level of the config file:

dir: "src"
excludeDir: ".git"
interval: 1s
pattern: "**/*.go"
exclude: "exclude"
build: "build cmd 1"
run: "run cmd"

A minimal sample revolver.yml file looks like the following:

build: "go install"

Config options:

Name	Type	Default value
dir	string	. (current dir)
excludeDir	[]string	[]
interval	duration	500ms
action	[]Action	[]

Action options:

Name	Type	Default value
name	string
pattern	[]string	[**/*]
exclude	[]string	[]
build	[]string	[]
run	string

Revolver can also be used without a config file. If a build(-b) or run(-r) command line flag is present, it will ignore the config file and configure the application with the specified flags instead. It is possible to add multiple excludeDir(-ed), patter (-p), exclude(-e) and build(-b) flags (ex: revolver -b "echo 1" -b "echo 2"').

The following flags can be used:

Usage of revolver:
  -b value
        Build commands
  -c string
        Path to config file (default "revolver.yml")
  -d string
        Directory to watch
  -e value
        File watch exclude patterns
  -ed value
        Excluded directories
  -i duration
        Poll interval
  -p value
        File watch patterns
  -r string
        Run command

File patterns

File patterns are supported for the pattern, exclude and excludeDir options. The pattern options defaults to every file in every directory (**/*), the exclude and excludeDir options are empty by default.

The following special terms are supported in the patterns:

Special Terms	Meaning
*	matches any sequence of non-path-separators
**	matches any sequence of characters, including path separators
?	matches any single non-path-separator character
[class]	matches any single non-path-separator character against a class of characters
{alt1,...}	matches a sequence of characters if one of the comma-separated alternatives matches

Any character with a special meaning can be escaped with a backslash (\).

Character classes support the following:

Class	Meaning
[abc]	matches any single character within the set
[a-z]	matches any single character in the range
[^class]	matches any single character which does not match the class

Actions

You can specify multiple actions with different file watch patterns that execute different commands.

Build commands

Build commands are commands that are executed when a file changes. Build commands are executed in order and if any of them errors out, the execution chain stops.

Run commands

Run commands are long running processes that are started when all the build commands are successfully executed. They are killed and restarted every time a file changes.

License

Authored by Kristóf Szabó and released under the MIT license.