config

Documentation

Overview

Package config is the YAML parser of the task file for Dunner.

For more information on how to write a task file for Dunner, please refer to the following link of an article on Dunner repository's Wiki: https://github.com/leopardslab/dunner/dunner/wiki/User-Guide#how-to-write-a-dunner-file

Usage

You can use the library by creating a dunner task file. For example,

# .dunner.yaml
prepare:
  - image: node
	commands:
	  - ["node", "--version"]
  - image: node
	commands:
	  - ["npm", "install"]
  - image: mvn
	commands:
	  - ["mvn", "package"]

Use `GetConfigs` method to parse the dunner task file, and `ParseEnv` method to parse environment variables file, or the host environment variables. The environment variables are used by invoking in the task file using backticks(`$var`).

Index

• func DecodeMount(mounts []string, step *docker.Step) error
• func ParseEnv(configs *Configs) error
• func ParseMountDir(ctx context.Context, fl validator.FieldLevel) bool
• func ValidateFollowTaskPresent(ctx context.Context, fl validator.FieldLevel) bool
• func ValidateMountDir(ctx context.Context, fl validator.FieldLevel) bool
• type Configs
  • func GetConfigs(filename string) (*Configs, error)
  • func (configs *Configs) Validate() []error
• type Task

Functions

func DecodeMount

func DecodeMount(mounts []string, step *docker.Step) error

DecodeMount parses mount format for directories to be mounted as bind volumes. The format to configure a mount is

<source>:<destination>:<mode>

By _mode_, the file permission level is defined in two ways, viz., _read-only_ mode(`r`) and _read-write_ mode(`wr` or `w`)

func ParseEnv

func ParseEnv(configs *Configs) error

ParseEnv parses the `.env` file as well as the host environment variables. If the same variable is defined in both the `.env` file and in the host environment, priority is given to the .env file.

Note: You can change the filename of environment file (default: `.env`) using `--env-file/-e` flag in the CLI.

func ParseMountDir

func ParseMountDir(ctx context.Context, fl validator.FieldLevel) bool

ParseMountDir verifies that source directory exists and parses the environment variables used in the config

func ValidateFollowTaskPresent

func ValidateFollowTaskPresent(ctx context.Context, fl validator.FieldLevel) bool

ValidateFollowTaskPresent verifies that referenceed task exists

func ValidateMountDir

func ValidateMountDir(ctx context.Context, fl validator.FieldLevel) bool

ValidateMountDir verifies that mount values are in proper format

<source>:<destination>:<mode>

Format should match, <mode> is optional which is `readOnly` by default and `src` directory exists in host machine

Types

type Configs

type Configs struct {
	Tasks map[string][]Task `validate:"required,min=1,dive,keys,required,endkeys,required,min=1,required"`
}

Configs describes the parsed information from the dunner file. It is a map of task name as keys and the list of tasks associated with it.

func GetConfigs

func GetConfigs(filename string) (*Configs, error)

GetConfigs reads and parses tasks from the dunner task file. The task file is unmarshalled to an object of struct `Config` The default filename that is being read by Dunner during the time of execution is `dunner.yaml`, but it can be changed using `--task-file` flag in the CLI.

func (*Configs) Validate

func (configs *Configs) Validate() []error

Validate validates config and returns errors.

type Task

type Task struct {
	// Name given as string to identify the task
	Name string `yaml:"name"`

	// Image is the repo name on which Docker containers are built
	Image string `yaml:"image" validate:"required"`

	// SubDir is the primary directory on which task is to be run
	SubDir string `yaml:"dir"`

	// The command which runs on the container and exits
	Command []string `yaml:"command" validate:"omitempty,dive,required"`

	// The list of commands that are to be run in sequence
	Commands [][]string `yaml:"commands" validate:"omitempty,dive,omitempty,dive,required"`

	// The list of environment variables to be exported inside the container
	Envs []string `yaml:"envs"`

	// The directories to be mounted on the container as bind volumes
	Mounts []string `yaml:"mounts" validate:"omitempty,dive,min=1,mountdir,parsedir"`

	// The next task that must be executed if this does go successfully
	Follow string `yaml:"follow" validate:"omitempty,follow_exist"`

	// The list of arguments that are to be passed
	Args []string `yaml:"args"`
}

Task describes a single task to be run in a docker container