shuttle

README

A CLI for handling shared build and deploy tools between many projects no matter what technologies the project is using.
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Table of contents

• What is shuttle?
• Status
• How?
• Features
• Documentation
• Installing
• Functions
• Release History

What is shuttle?

shuttle is a CLI for handling shared build and deploy tools between many projects no matter what technologies the project is using.

Status

DISCLAIMER: shuttle is in beta, so stuff may change. However we are using shuttle heavily at Lunar Way and we use it to deploy to production, so it is pretty battle proven.

How?

Projects that use shuttle are always referencing a shuttle plan. A plan describes what can be done with shuttle. Fx:

# plan.yaml file
scripts:
  build:
    description: Build the docker image
    args:
      - name: tag
        required: true
    actions:
      - shell: docker -f $plan/Dockerfile build -t $(shuttle get docker.image):$tag
  test:
    description: Run test for the project
    actions:
      - shell: go test

The plan.yaml is located at the root of the plan directory which is located elsewhere of the actual project using it. The plan directory can be locally stored or in a git repository. The directory structure could be something like:

workspace
│
└───moon-base          # project
│   │   shuttle.yaml   # project specific shuttle.yaml file
│   │   main.go
│
└───station-plan       # plan to be shared by projects
    │   plan.yaml
    │   Dockerfile

To use a plan a project must specify the shuttle.yaml file:

plan: ../the-plan
vars:
  docker:
    image: earth-united/moon-base

With this in place a docker image can be built:

$ cd workspace/moon-base
$ shuttle run build tag=v1

You can also put your plan.yaml in a different git repository, and then reference it from your shuttle.yaml:

# shuttle.yaml
plan: git://git@github.com:lunarway/station-plan.git

Features

• Fetch shuttle plans from git repositories
• Create any script you like in the plan
• Overwrite scripts in local projects when they defer from the plan
• Write templates in plans and overwrite them in projects when they defer
• ...

Documentation

Plan documentation can be inspected using the shuttle documentation command.

When writing shuttle plans you can hint as to where to find documentation for the plan. Users of the plan will open the specified URL when requesting documentation.

# plan.yaml
documentation: https://docs.my-corp.com

If no specific documentation field is set in the plan it will be inferred from the plan reference. In below example shuttle will open https://github.com/lunarway/shuttle-example-go-plan.git

# shuttle.yaml
plan: git://git@github.com:lunarway/shuttle-example-go-plan.git

Git Plan

Specify the protocol to use for pulling the remote repository using either https:// for HTTPS, or git:// for SSH:

• https://github.com/lunarway/shuttle-example-go-plan.git
• git://git@github.com:lunarway/shuttle-example-go-plan.git

Choose a specific branch to use:

• https://github.com/lunarway/shuttle-example-go-plan.git#change-build
• git://git@github.com:lunarway/shuttle-example-go-plan.git#change-build

The #change-build points the plan to a specific branch, which by default would be master.

It can also be used to point to a tag or a git SHA, like this:

• https://github.com/lunarway/shuttle-example-go-plan.git#v1.2.3
• git://git@github.com:lunarway/shuttle-example-go-plan.git#46ce3cc

Caching

By default shuttle will pull the upstream plan on every pull. To prevent this you can use

export SHUTTLE_CACHE_DURATION_MIN=60 # Cache a plan for 60 minutes

This feature caches pr. repo, as such the cache isn't shared between working repositories.

Overloading the plan

It is possible to overload the plan specified in shuttle.yaml file by using the --plan argument or the SHUTTLE_PLAN_OVERLOAD environment variable. Following arguments are supported

• A path to a local plan like --plan ../local-checkout-of-plan. Absolute paths is also supported
• Another git plan like --plan git://github.com/some-org/some-plan
• A git tag to append to the plan like --plan #some-branch, --plan #some-tag or a SHA --plan #2b52c21

Installing

Mac OS

curl -LO https://github.com/lunarway/shuttle/releases/download/$(curl -Lso /dev/null -w %{url_effective} https://github.com/lunarway/shuttle/releases/latest | grep -o '[^/]*$')/shuttle-darwin-amd64
chmod +x shuttle-darwin-amd64
sudo mv shuttle-darwin-amd64 /usr/local/bin/shuttle

Linux

curl -LO https://github.com/lunarway/shuttle/releases/download/$(curl -Lso /dev/null -w %{url_effective} https://github.com/lunarway/shuttle/releases/latest | grep -o '[^/]*$')/shuttle-linux-amd64
chmod +x shuttle-linux-amd64
sudo mv shuttle-linux-amd64 /usr/local/bin/shuttle

GitHub Actions

Shuttle can be installed on your GitHub Runner by adding this line to your workflow:

- use: lunarway/shuttle

After this point you can use shuttle in the scripts in your workflow job.

Functions

shuttle get <variable>

Used to get a variable defined in shuttle.yaml

$ shuttle get some.variable
> some variable content

$ shuttle get does.not.exist
> # nothing

shuttle plan

Inspect the plan in use for a project. Use the template flag to customize the output to your needs.

$ shuttle plan
https://github.com/lunarway/shuttle-example-go-plan.git

shuttle has <variable>

It is possible to easily check if a variable or script is defined

shuttle has some.variable
shuttle has --script integration

Output is either statuscode=0 if variable is found or statuscode=1 if variables isn't found. The output can also be a stdout boolean like

$ shuttle has my.docker.image --stdout
> false

Template functions

The template command along with commands taking a --template flag has multiple templating functions available. The masterminds/sprig v3.2.2 functions are available along with those described below.

Examples are based on the below shuttle.yaml file.

Function	Description	Example	Output
array <path> <value>	Get array from path. If value is a map, the values of the map is returned in deterministic order.	array "args" .	helloworld
fileExists <file-path>	Returns whether a file exists.	fileExists ".gitignore"	true
fromYaml <value>	Unmarshal YAML string to a map[string]interface{}. In case of YAML parsing errors the Error key in the result contains the error message. See notes below on usage.	fromYaml "api: v1"	map[api:v1]
get <path> <value>	Get a value from a field path. . is read as nested nested objects	get "docker.image" .	earth-united/moon-base
getFileContent <file-path>	Get raw contents of a file.	getFileContent ".gitignore"	dist/ vendor/ ...
getFiles <directory-path>	Returns a slice of files in the provided directory as os.FileInfo structs.	{{ range $i, $f := (getFiles "./") }}{{ .Name }} {{ end }}	.git .gitignore ...
int <path> <value>	Get int value without formatting. Note that this is a direct int cast ie. value 1.2 will generate an error.	int "replicas" .	1
is <value-a> <value-b>	Equality indication by Go's == comparison.	is "foo" "bar"	false
isnt <value-a> <value-b>	Inequality indication by Go's != comparison.	isnt "foo" "bar"	true
objectArray <path> <value>	Get object key-value pairs from path. Each key-value is returned in a { Key Value} object.	{{ range objectArray "docker" . }}{{ .Key }} -> {{ .Value }}{{ end }}	image -> earth-united/moon-base
rightPad <string> <padding>	Add space padding to the right of a string.	{{ rightPad "padded" 10 }}string	padded string
strConst <value>	Convert string to upper snake casing converting . to _.	strConst "a.value"	A_VALUE
string <path> <value>	Format any value as a string.	string "replicas" .	"1"
toYaml <value>	Marshal value to YAML. In case of non-parsable string an empty string is returned. See notes below on usage.	toYaml (get "args" .)	- hello - world
trim <string>	Trim leading and trailing whitespaces. Uses strings.TrimSpace.	trim " a string "	a string
upperFirst <string>	Upper case first character in string.	upperFirst "a string"	A string

plan: ../the-plan
vars:
  docker:
    image: earth-united/moon-base
  replicas: 1
  args:
    - hello
    - world

Notes on YAML parsers: The toYaml and fromYaml template functions are intented to be used inside file templates (not template flags). Because of this they ignore errors and some YAML documents canont be parsed.

Release History

See the releases for more information on changes between releases.