Tugboat Documentation > Reference > Tugboat Configuration

Tugboat Configuration

The following attributes control how a Service is built:

Key	Type	Description
image	String	The Docker image to use for this Service
checkout	Boolean	Whether to clone the git repository to this Service
checkout_path	String	Where to clone the git repository
depends	List	List of other Services that this Service depends on
commands	List	List of commands to run for various build stages

The following attributes configure how Service URLs are generated

Key	Type	Description
aliases	List	A list of aliases to generate URLs for
alias_type	String	What kind of aliases to generate
subpath	Boolean	Whether subpath URLs should be generated for this Service

The following attributes configure how the Tugboat proxy routes HTTP requests to the Service:

Key	Type	Description
expose	Integer	Which port the Service should expose to the Tugboat proxy
default	Boolean	Whether this is the default Service for a Preview.
http	Boolean	Whether the Service should be available via HTTP
https	Boolean	Whether the Service should be available via HTTPS
domain	String	A custom domain for Tugboat to generate URLs with
subpath_map	Boolean	Whether to map the generated subpath to “/”

The following attributes control which Service URLs are processed after a Preview is built, rebuilt, or refreshed.

Key	Type	Description
lighthouse	List	Lighthouse configurations to use for all URLs processed for the Service
screenshot	List	Screenshot configurations to use for all URLs processed for the Service
visualdiff	List	Visual Diff configurations to use for all URLs processed for the Service
urls	List	Which URLs should be processed for the Service

The following attributes have been deprecated

Key	Type	Description
visualdiffs	List	List of visualdiffs to generate for the Service

`alias_type`

Type: String
Default: default
Required: No

What type of URL aliases to generate for the Service. Valid options are default or domain. Alias URLs are generated in addition to the normal Service URLs.

default

When alias_type is set to default, the alias URLs are constructed by substituting the preview name in the Service URL with the values of aliases. The values of aliases are sanitized based on the value of subpath.

If subpath is false, alias values are sanitized to create a valid host name, and is truncated to 30 characters, to make the host name a maximum of 63 characters. If subpath is true, the alias values are URL encoded.

If aliases is set to ['foo', 'bar'], alias URLs look like the following

domain

When alias_type is set to domain, the alias URLs are constructing by substituting the domain part of the Service URL with the values of aliases. The alias values are sanitized to create a valid domain name. If aliases is set to ['foo.com', 'bar.com'], alias URLs look like the following

In order for these domains to resolve, a DNS entry must be added to the alias domains as a CNAME to previews.tugboat.qa. A wildcard entry is required if subpath is set to false.

`aliases`

Type: List
Default: no default
Required: No

A list of aliases to generate URLs for. If set, additional alias URLs will be generated for the service. These URLs can be used to route to different endpoints inside of the Service, such as for a Drupal Multisite. How the alias URLs are constructed depend on the value of alias_type

`checkout`

Type: Boolean
Default: false (true when default: true is set)
Required: No

Whether or not this Service should have a copy of the git repository cloned into it.

`checkout_path`

Type: String
Default: /var/lib/tugboat
Required: No

Specifies the path where the git repository should be cloned if checkout: true is set. If this path already exists, the clone will fail.

`commands`

Type: List
Default: no default
Required: No

A set of commands to run during various points in a Preview’s lifecycle. These commands are divided into the following stages. Each stage consists of a list of commands. Each command is run in its own context, so things like changing directories does not “stick” between commands. If that behavior is required, an external script should be called.

Stage	Description
init	Commands that set up the basic Preview infrastructure, such as required packages or tools
update	Commands that import data or other assets into a service, such as a database or image files
build	Commands that build or generate the site, such as compiling Sass or running database updates from code
ready	Commands that indicate that a service is “ready”, such as checking for a listening TCP port
online	Commands to run once, after a Preview has built, is online, and is ready to accept incoming requests
start	Commands that should be run every time a Preview starts
clone	Commands that should be run on the cloned (new) Preview that has been created from an existing Preview

The init, update, and build stages are related as follows:

When a Preview is created, the commands in init are run, followed by the commands in update, and finally the commands in build.
When a Preview is refreshed, the commands in update are run, followed by the commands in build.
When a Preview is created from a Base Preview, only the commands in build are run.

The online, start, and clone commands all run after the build snapshot, so these commands are executed after the build is complete (although cloneed commands are committed as a second build snapshot). For more info on the build snapshot, see: The Build Snapshot.

`default`

Type: Boolean
Default: false (true if only one service is defined)
Required: Yes, if more than one service is defined.

Whether this is the default Service for a Preview. The default Service is where incoming HTTP requests to the preview URL are routed. Setting this to true also implies expose: 80 and checkout: true unless those attributes are explicitly set otherwise.

`depends`

Type: List
Default: no default
Required: No

Defines the order in which commands are executed between the defined Services. If one Service has a dependency on another, it will wait for that Service’s commands to run before running its own commands. If not set, there is no guaranteed order in which Services will execute their commands relative to other Services.

`domain`

Type: String
Default: no default
Required: No

A custom domain to use when generating URLs for the Service. If example.com is used, for example, URLs for the service will resemble http://pr123-token.example.com or http://preview.example.com/pr123-token/, depending on the other configuration values. Note that using a custom domain will result in browsers issuing SSL/TLS certificate warnings when combined with https: true.

`expose`

Type: Integer
Default: no default (80 when default: true is set)
Required: No

If this Service should be publicly accessible via HTTP/HTTPS, this is the port that the Tugboat Proxy will forward incoming requests to.

`http`

Type: Boolean
Default: false
Required: No

By default, Tugboat only generates HTTPS URLs and forces a redirect to HTTPS. Setting this value to true changes this behavior to allow access to this Service’s URL directly via HTTP on port 80.

`https`

Type: Boolean
Default: true
Required: No

When true, this Service’s URL is public accessible via HTTPS on port 443. In order to disable HTTPS for a Service URL, https must be set to false, and http must be set to true. If both https and http are set to true, you’ll get both http and https links.

`image`

Type: String
Default: no default
Required: Yes

The Docker image to use for this Service. Tugboat maintains a set of images on Dockerhub. These images all extend the official docker images, and are configured to work well with Tugboat. See also: Specify a Service image.

`subpath`

Type: Boolean
Default: false
Required: No

When true, the URL generated for this Service will be a subpath of the root Preview domain instead of a subdomain. Using a subpath URL is not common, but can solve problems with testing advertisements or using OAuth

subpath	URL Example
`true`	https://preview.tugboat.qa/pr123-4vdrhxvyddvr5tne7zcr4y72vzowqohj/
`false`	https://pr123-4vdrhxvyddvr5tne7zcr4y72vzowqohj.tugboat.qa

`subpath_map`

Type: Boolean
Default: true
Required: No

When true, and subpath: true is set, URLs are rewritten by the Tugboat Proxy to replace the Preview-specific path with / before being forwarded to the Service. When false, URLs are passed through as-is.

`lighthouse`

Type: List
Default: no default
Required: No

Lighthouse configurations that affect all of the URLs defined for this Service. Values configured here override the Tugboat default values, but can also be overridden per-URL.

Option	Type	Default	Description
`enabled`	Boolean	`true`	Whether to render Lighthouse Reports for the URLs defined for this Service
`config`	Object		A custom Lighthouse configuration object to use while rendering Lighthouse Reports for the URLs defined for this Service
`screen`	List	`desktop`	Which screens should be used when rendering Lighthouse Reports. Valid options are `desktop` and/or `mobile`

Tugboat uses the default Lighthouse configuration, but disables a few of the server performance metrics. These metrics tend to be inaccurate due to the shared nature of the Tugboat infrastructure, and can negatively impact the overall Lighthouse score.

Documentation for creating a custom Lighthouse configuration can be found at https://github.com/GoogleChrome/lighthouse/blob/HEAD/docs/configuration.md

`screenshot`

Type: List
Default: no default
Required: No

Screenshot configurations that affect all of the URLs defined for this Service. Values configured here override the Tugboat default values, and can also be overridden per-URL.

Option	Type	Default	Description
`enabled`	Boolean	`true`	Whether to render Screenshots for the URLs defined for this Service
`fullPage`	Boolean	`true`	Whether to use the default `fullPage` method. Disabling this uses an alternative that is more friendly to elements that have `vh` CSS Styles, but can sometimes be less accurate
`timeout`	Number	`30`	How long to wait for a page to be ready when taking a screenshot, in seconds. Minimum: `1`, Maximum: `300`
`waitUntil`	String	`load`	Which browser event to wait for before creating a screenshot of the page

`waitUntil`

The waitUntil option can be one of, or a list of, the following events. If a list of events is given, the screenshot is created after all of the specified events have fired

Event	Description
load	Fires when the `load` event is fired
domcontentloaded	Fires when the `DOMContentLoaded` event is fired
networkidle0	Fires when there are no more than 0 network connections for at least 500ms
networkidle2	Fires when there are no more than 2 network connections for at least 500ms

`visualdiff`

Type: List
Default: no default
Required: No

Visual Diff configurations that affect all of the URLs defined for this Service. Values configured here override the Tugboat default values, and can also be overridden per-URL.

Visual Diffs can only be automatically generated for Previews built from a Base Preview. These options apply to screenshots taken of the Base Preview used to compare to screenshots taken of this Preview.

Option	Type	Default	Description
`enabled`	Boolean	`true`	Whether to render Visual Diffs for the URLs defined for this Service. Visual Diffs depend on Screenshots being enabled. If Screenshots are disabled, this setting has no effect.
`fullPage`	Boolean	`true`	Whether to use the default `fullPage` method. Disabling this uses an alternative that is more friendly to elements that have `vh` CSS Styles, but can sometimes be less accurate
`timeout`	Number	`30`	How long to wait for a page to be ready when taking a screenshot, in seconds. Minimum: `1`, Maximum: `300`
`waitUntil`	String	`load`	Which browser event to wait for before creating a screenshot of the page
`threshold`	Number or Object	`0`	What percent similar a Visual Diff must be to the base preview in order to “pass”. Visual Diffs that are less similar than this will generate an error. Minimum: `0`, Maximum: `100`

visualdiff:
  enabled: true
  fullPage: true
  timeout: 30
  waitUntil: load
  threshold: 0

`waitUntil`

The visualdiff waitUntil option can be one of, or a list of, the following events. If a list of events is given, the screenshot is created after all of the specified events have fired

Event	Description
load	Fires when the `load` event is fired
domcontentloaded	Fires when the `DOMContentLoaded` event is fired
networkidle0	Fires when there are no more than 0 network connections for at least 500ms
networkidle2	Fires when there are no more than 2 network connections for at least 500ms

waitUntil:
  - load
  - networkidle0

`threshold`

The visualdiff threshold option can be either an integer or an object. If it is an object, granular thresholds can be defined for each of the following screen types

desktop
tablet
mobile

If any of the screen types are not present, the threshold for that screen is set to 0.

threshold:
  desktop: 99
  tablet: 95
  mobile: 90

If threshold is set to an integer, each of the above values are set to that value.

threshold: 99

`urls`

Type: List
Default: no default
Required: No

Which URLs should be processed when a Preview has finished building. You can define URLs on any service that has an exposed port. The URLs can be specified using one of the following formats:

Simple URL List

A simple list of strings can be provided. Each of the URLs will be processed according to the default Tugboat configurations, or by Service-level lighthouse, screenshot, or visualdiff configurations

urls:
  - /
  - /blog
  - /about

Advanced URL List

Each URL can be given configuration options that override the Tugboat defaults, or any Service-level configurations.

Option	Type	Default	Description
url	String	none	The relative URL to process. This option is required.
aliases	List	`:default`	Use this list of Service aliases when processing this URL. Each alias listed will be processed as an individual URL
lighthouse	List		Lighthouse configurations for this URL that override the Tugboat default, and specified Service-level lighthouse configurations
screenshot	List		Screenshot configurations for this URL that override the Tugboat default, and specified Service-level lighthouse configurations
visualdiff	List		Visual Diff configurations for this URL that override the Tugboat default, and specified Service-level lighthouse configurations

The special :default alias tells Tugboat to use the default Service URL with no alias.

lighthouse, screenshot, and visualdiff configuration options are the same as the Service-level options

Advanced URLs can be mixed with Simple URLs.

urls:
  - /
  - /blog
  - url: /about
    aliases:
      - :default
      - foo
      - bar
    lighthouse:
      enabled: false
    screenshot:
      timeout: 45
    visualdiff:
      fullPage: false

Alias Groups

URLs can be grouped by alias, which is particularly useful if the aliases have different URL structures. Alias groups can contain any combination of Simple or Advanced URL definitions as described above. The special :default alias means to use the default Service URL with no alias.

urls:
  :default:
    - /
    - /about
  foo:
    - url: /about
      lighthouse:
        enabled: false
  bar:
    - /
    - /blog

`visualdiffs`

This configuration is deprecated. Please use urls instead.

Type: List
Default: no default
Required: No

A set of visual diffs that should be generated for the Service. These visual diffs are generated automatically when a Preview is created with a base preview. They are then updated when the Preview is refreshed or rebuilt.

The visual diffs are specified by providing a list of relative URLs to the Service. Each item in this list can be either a string, such as /blog, or a map overriding the following screenshot options:

Option	Default	Description
url	none	The relative URL to create the visual diff for. This option is required
aliases	`:default`	Only create visual diffs for these Service aliases. The special `:default` alias can be used to also generate a visual diff without an alias
timeout	`30`	How long to wait for a page to be ready when taking a screenshot, in seconds. Minimum: `1`, Maximum: `300`
waitUntil	`load`	Which event to wait for before creating a screenshot of a page.
fullPage	`true`	Disable this to use an alternate screenshot method that is more friendly to elements that have `vh` CSS styles

The waitUntil option can be one of, or a list of, the following events. If a list of events is given, the screenshot is created after all of the specified events have fired

Event	Description
load	Fires when the `load` event is fired
domcontentloaded	Fires when the `DOMContentLoaded` event is fired
networkidle0	Fires when there are no more than 0 network connections for at least 500ms
networkidle2	Fires when there are no more than 2 network connections for at least 500ms

The visual diff URLs can optionally be grouped by Service alias, which is convenient when aliases have different URL structures. Group URLs by nesting them in a map with the name of the alias they belong to. The special :default alias can be used to create a group of URLs that should not use an alias.