Jib - Containerize your Gradle Java project

Jib is a Gradle plugin for building Docker and OCI images for your Java applications.

For the Maven plugin, see the jib-maven-plugin project.

For information about the project, see the Jib project README.

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Quickstart

Setup

Make sure you are using Gradle version 5.1 or later.

In your Gradle Java project, add the plugin to your build.gradle:

plugins {
  id 'com.google.cloud.tools.jib' version '3.4.4'
}

See the Gradle Plugin Portal for more details.

You can containerize your application easily with one command:

gradle jib --image=<MY IMAGE>

This builds and pushes a container image for your application to a container registry. If you encounter authentication issues, see Authentication Methods.

To build to a Docker daemon, use:

gradle jibDockerBuild

If you would like to set up Jib as part of your Gradle build, follow the guide below.

Configuration

Configure the plugin by setting the image to push to:

Using Google Container Registry (GCR)...

Make sure you have the docker-credential-gcr command line tool. Jib automatically uses docker-credential-gcr for obtaining credentials. See Authentication Methods for other ways of authenticating.

For example, to build the image gcr.io/my-gcp-project/my-app, the configuration would be:

jib.to.image = 'gcr.io/my-gcp-project/my-app'

Using Amazon Elastic Container Registry (ECR)...

Make sure you have the docker-credential-ecr-login command line tool. Jib automatically uses docker-credential-ecr-login for obtaining credentials. See Authentication Methods for other ways of authenticating.

For example, to build the image aws_account_id.dkr.ecr.region.amazonaws.com/my-app, the configuration would be:

jib.to.image = 'aws_account_id.dkr.ecr.region.amazonaws.com/my-app'

Using Docker Hub Registry...

Make sure you have a docker-credential-helper set up. For example, on macOS, the credential helper would be docker-credential-osxkeychain. See Authentication Methods for other ways of authenticating.

For example, to build the image my-docker-id/my-app, the configuration would be:

jib.to.image = 'my-docker-id/my-app'

Using JFrog Container Registry (JCR) or JFrog Artifactory...

Make sure you have a docker-credential-helper set up. For example, on macOS, the credential helper would be docker-credential-osxkeychain. See Authentication Methods for other ways of authenticating.

For example, to build the image my-company-docker-local.jfrog.io/my-app, the configuration would be:

jib.to.image = 'my-company-docker-local.jfrog.io/my-app'

Using Azure Container Registry (ACR)...

Make sure you have a ACR Docker Credential Helper installed and set up. For example, on Windows, the credential helper would be docker-credential-acr-windows. See Authentication Methods for other ways of authenticating.

For example, to build the image my_acr_name.azurecr.io/my-app, the configuration would be:

jib.to.image = 'my_acr_name.azurecr.io/my-app'

Build Your Image

Build your container image with:

gradle jib

Subsequent builds are much faster than the initial build.

Having trouble? Let us know by submitting an issue, contacting us on Gitter, or posting to the Jib users forum.

Build to Docker daemon

Jib can also build your image directly to a Docker daemon. This uses the docker command line tool and requires that you have docker available on your PATH.

gradle jibDockerBuild

If you are using minikube's remote Docker daemon, make sure you set up the correct environment variables to point to the remote daemon:

eval $(minikube docker-env)
gradle jibDockerBuild

Alternatively, you can set environment variables in the Jib configuration. See dockerClient for more configuration options.

Build an image tarball

You can build and save your image to disk as a tarball with:

gradle jibBuildTar

This builds and saves your image to build/jib-image.tar, which you can load into docker with:

docker load --input build/jib-image.tar

Run `jib` with each build

You can also have jib run with each build by attaching it to the build task:

tasks.build.dependsOn tasks.jib

Then, gradle build will build and containerize your application.

Additional Build Artifacts

As part of an image build, Jib also writes out the image digest and the image ID. By default, these are written out to build/jib-image.digest and build/jib-image.id respectively, but the locations can be configured using the jib.outputPaths.digest and jib.outputPaths.imageId configuration properties. See Extended Usage for more details.

Multi Module Projects

Special handling of project dependencies is recommended when building complex multi module projects. See Multi Module Example for detailed information.

Extended Usage

The plugin provides the jib extension for configuration with the following options for customizing the image build:

Field	Type	Default	Description
`to`	`to`	Required	Configures the target image to build your application to.
`from`	`from`	See `from`	Configures the base image to build your application on top of.
`container`	`container`	See `container`	Configures the container that is run from your built image.
`extraDirectories`	`extraDirectories`	See `extraDirectories`	Configures the directories used to add arbitrary files to the image.
`outputPaths`	`outputPaths`	See `outputPaths`	Configures the locations of additional build artifacts generated by Jib.
`dockerClient`	`dockerClient`	See `dockerClient`	Configures Docker for building to/from the Docker daemon.
`skaffold`	`skaffold`	See `skaffold`	Configures the internal skaffold tasks. This configuration should only be used when integrating with `skaffold`.
`containerizingMode`	`String`	`exploded`	If set to `packaged`, puts the JAR artifact built by the Gradle Java plugin into the final image. If set to `exploded` (default), containerizes individual `.class` files and resources files.
`allowInsecureRegistries`	`boolean`	`false`	If set to true, Jib ignores HTTPS certificate errors and may fall back to HTTP as a last resort. Leaving this parameter set to `false` is strongly recommended, since HTTP communication is unencrypted and visible to others on the network, and insecure HTTPS is no better than plain HTTP. If accessing a registry with a self-signed certificate, adding the certificate to your Java runtime's trusted keys may be an alternative to enabling this option.
`configurationName`	`String`	`runtimeClasspath`	Specify the name of the Gradle Configuration to use.

from is a closure with the following properties:

Property	Type	Default	Description
`image`	`String`	`eclipse-temurin:{8,11,17,21}-jre` (or `jetty` for WAR)	The image reference for the base image. The source type can be specified using a special type prefix.
`auth`	`auth`	None	Specifies credentials directly (alternative to `credHelper`).
`credHelper`	`String`	None	Specifies a credential helper that can authenticate pulling the base image. This parameter can either be configured as an absolute path to the credential helper executable or as a credential helper suffix (following `docker-credential-`).
`platforms`	`platforms`	See `platforms`	Configures platforms of base images to select from a manifest list.

to is a closure with the following properties:

Property	Type	Default	Description
`image`	`String`	Required	The image reference for the target image. This can also be specified via the `--image` command line option. If the tag is not present here `:latest` is implied.
`auth`	`auth`	None	Specifies credentials directly (alternative to `credHelper`).
`credHelper`	`String`	None	Specifies a credential helper that can authenticate pushing the target image. This parameter can either be configured as an absolute path to the credential helper executable or as a credential helper suffix (following `docker-credential-`).
`tags`	`List<String>`	None	Additional tags to push to.

auth is a closure with the following properties (see Using Specific Credentials):

Property	Type
`username`	`String`
`password`	`String`

platforms can configure multiple platform closures. Each individual platform has the following properties:

Property	Type	Default	Description
`architecture`	`String`	`amd64`	The architecture of a base image to select from a manifest list.
`os`	`String`	`linux`	The OS of a base image to select from a manifest list.

See How do I specify a platform in the manifest list (or OCI index) of a base image? for examples.

container is a closure with the following properties:

Property	Type	Default	Description
`appRoot`	`String`	`/app`	The root directory on the container where the app's contents are placed. Particularly useful for WAR-packaging projects to work with different Servlet engine base images by designating where to put exploded WAR contents; see WAR usage as an example.
`args`	`List<String>`	None	Additional program arguments appended to the command to start the container (similar to Docker's CMD instruction in relation with ENTRYPOINT). In the default case where you do not set a custom `entrypoint`, this parameter is effectively the arguments to the main method of your Java application.
`creationTime`	`String`	`EPOCH`	Sets the container creation time. (Note that this property does not affect the file modification times, which are configured using `jib.container.filesModificationTime`.) The value can be `EPOCH` to set the timestamps to Epoch (default behavior), `USE_CURRENT_TIMESTAMP` to forgo reproducibility and use the real creation time, or an ISO 8601 date-time parsable with `DateTimeFormatter.ISO_DATE_TIME` such as `2019-07-15T10:15:30+09:00` or `2011-12-03T22:42:05Z`. The value can also be initialized lazily with a provider.
`entrypoint`	`List<String>`	None	The command to start the container with (similar to Docker's ENTRYPOINT instruction). If set, then `jvmFlags`, `mainClass`, `extraClasspath`, and `expandClasspathDependencies` are ignored. You may also set `jib.container.entrypoint = 'INHERIT'` to indicate that the `entrypoint` and `args` should be inherited from the base image.* The value can also be initialized lazily with a provider.
`environment`	`Map<String, String>`	None	Key-value pairs for setting environment variables on the container (similar to Docker's ENV instruction).
`extraClasspath`	`List<String>`	None	Additional paths in the container to prepend to the computed Java classpath.
`expandClasspathDependencies`	`boolean`	`false`	Java 8 or Jib < 3.1: When set to true, does not use a wildcard (for example, `/app/lib/`) for dependency JARs in the default Java runtime classpath but instead enumerates the JARs. Has the effect of preserving the classpath loading order as defined by the Gradle project. Java >= 9 and* Jib >= 3.1: The option has no effect. Jib always enumerates the dependency JARs. This is achieved by creating and using an argument file for the `--class-path` JVM argument.
`filesModificationTime`	`String`	`EPOCH_PLUS_SECOND`	Sets the modification time (last modified time) of files in the image put by Jib. (Note that this does not set the image creation time, which can be set using `jib.container.creationTime`.) The value should either be `EPOCH_PLUS_SECOND` to set the timestamps to Epoch + 1 second (default behavior), or an ISO 8601 date-time parsable with `DateTimeFormatter.ISO_DATE_TIME` such as `2019-07-15T10:15:30+09:00` or `2011-12-03T22:42:05Z`. The value can also be initialized lazily with a provider.
`format`	`String`	`Docker`	Use `OCI` to build an OCI container image.
`jvmFlags`	`List<String>`	None	Additional flags to pass into the JVM when running your application. The value can also be initialized lazily with a provider.
`labels`	`Map<String, String>`	None	Key-value pairs for applying image metadata (similar to Docker's LABEL instruction).
`mainClass`	`String`	Inferred**	The main class to launch your application from. The value can also be initialized lazily with a provider.
`ports`	`List<String>`	None	Ports that the container exposes at runtime (similar to Docker's EXPOSE instruction).
`user`	`String`	None	The user and group to run the container as. The value can be a username or UID along with an optional groupname or GID. The following are all valid: `user`, `uid`, `user:group`, `uid:gid`, `uid:group`, `user:gid`.
`volumes`	`List<String>`	None	Specifies a list of mount points on the container.
`workingDirectory`	`String`	None	The working directory in the container.

extraDirectories is a closure with the following properties (see Adding Arbitrary Files to the Image):

Property	Type	Default	Description
`paths`	`paths` closure, or `Object`	`(project-dir)/src/main/jib`	May be configured as a closure configuring `path` elements, or as source directory values recognized by `Project.files()`, such as `String`, `File`, `Path`, `List<String\|File\|Path>`, etc.
`permissions`	`Map<String, String>`	None	Maps file paths (glob patterns) on container to Unix permissions. (Effective only for files added from extra directories.) If not configured, permissions default to "755" for directories and "644" for files. See Adding Arbitrary Files to the Image for an example.

paths can configure multiple path closures (see Adding Arbitrary Files to the Image). Each individual path has the following properties:

Property	Type	Default	Description
`from`	`Object`	`(project-dir)/src/main/jib`	Accepts source directories that are recognized by `Project.files()`, such as `String`, `File`, `Path`, `List<String\|File\|Path>`, etc.
`into`	`String`	`/`	The absolute unix path on the container to copy the extra directory contents into.
`includes`	`List<String>`	None	Glob patterns for including files. See Adding Arbitrary Files to the Image for an example.
`excludes`	`List<String>`	None	Glob patterns for excluding files. See Adding Arbitrary Files to the Image for an example.

outputPaths is a closure with the following properties:

Property	Type	Default	Description
`tar`	`File`	`(project-dir)/build/jib-image.tar`	The path of the tarball generated by `jibBuildTar`. Relative paths are resolved relative to the project root.
`digest`	`File`	`(project-dir)/build/jib-image.digest`	The path of the image digest written out during the build. Relative paths are resolved relative to the project root.
`imageId`	`File`	`(project-dir)/build/jib-image.id`	The path of the image ID written out during the build. Relative paths are resolved relative to the project root.

dockerClient is an object used to configure Docker when building to/from the Docker daemon. It has the following properties:

Property	Type	Default	Description
`executable`	`File`	`docker`	Sets the path to the Docker executable that is called to load the image into the Docker daemon. Please note: Users are responsible for ensuring that the Docker path passed in is valid and has the right permissions to be executed.
`environment`	`Map<String, String>`	None	Sets environment variables used by the Docker executable.

System Properties

Each of these parameters is configurable via commandline using system properties. Jib's system properties follow the same naming convention as the configuration parameters, with each level separated by dots (i.e. -Djib.parameterName[.nestedParameter.[...]]=value). Some examples are below:

gradle jib \
    -Djib.to.image=myregistry/myimage:latest \
    -Djib.to.auth.username=$USERNAME \
    -Djib.to.auth.password=$PASSWORD

gradle jibDockerBuild \
    -Djib.dockerClient.executable=/path/to/docker \
    -Djib.container.environment=key1="value1",key2="value2" \
    -Djib.container.args=arg1,arg2,arg3

The following table contains additional system properties that are not available as build configuration parameters:

Property	Type	Default	Description
`jib.httpTimeout`	`int`	`20000`	HTTP connection/read timeout for registry interactions, in milliseconds. Use a value of `0` for an infinite timeout.
`jib.useOnlyProjectCache`	`boolean`	`false`	If set to true, Jib does not share a cache between different Gradle projects.
`jib.baseImageCache`	`File`	Platform-dependent***	Sets the directory to use for caching base image layers. This cache can (and should) be shared between multiple images.
`jib.applicationCache`	`File`	`[project dir]/build/jib-cache`	Sets the directory to use for caching application layers. This cache can be shared between multiple images.
`jib.console`	`String`	None	If set to `plain`, Jib will print plaintext log messages rather than display a progress bar during the build.

* If you configure args while entrypoint is set to 'INHERIT', the configured args value will take precedence over the CMD propagated from the base image.

** Uses the main class defined in the jar task or tries to find a valid main class.

*** The default base image cache is in the following locations on each platform:

Linux: [cache root]/google-cloud-tools-java/jib/, where [cache root] is $XDG_CACHE_HOME ($HOME/.cache/ if not set)
Mac: [cache root]/Google/Jib/, where [cache root] is $XDG_CACHE_HOME ($HOME/Library/Caches/ if not set)
Windows: [cache root]\Google\Jib\Cache, where [cache root] is %XDG_CACHE_HOME% (%LOCALAPPDATA% if not set)

Global Jib Configuration

Some options can be set in the global Jib configuration file. The file is at the following locations on each platform:

Linux: [config root]/google-cloud-tools-java/jib/config.json, where [config root] is $XDG_CONFIG_HOME ($HOME/.config/ if not set)
Mac: [config root]/Google/Jib/config.json, where [config root] is $XDG_CONFIG_HOME ($HOME/Library/Preferences/Config/ if not set)
Windows: [config root]\Google\Jib\Config\config.json, where [config root] is %XDG_CONFIG_HOME% (%LOCALAPPDATA% if not set)

Properties

disableUpdateCheck: when set to true, disables the periodic up-to-date version check.
registryMirrors: a list of mirror settings for each base image registry. In the following example, if the base image configured in Jib is for a Docker Hub image, then mirror.gcr.io, localhost:5000, and the Docker Hub (registry-1.docker.io) are tried in order until Jib can successfully pull a base image.

{
  "disableUpdateCheck": false,
  "registryMirrors": [
    {
      "registry": "registry-1.docker.io",
      "mirrors": ["mirror.gcr.io", "localhost:5000"]
    },
    {
      "registry": "quay.io",
      "mirrors": ["private-mirror.test.com"]
    }
  ]
}

Note about mirror.gcr.io: it is not a Docker Hub mirror but a cache. It caches frequently-accessed public Docker Hub images, and it's often possible that your base image does not exist in mirror.gcr.io. In that case, Jib will have to fall back to use Docker Hub.

Example

In this configuration, the image:

Is built from a base of openjdk:alpine (pulled from Docker Hub)
Is pushed to localhost:5000/my-image:built-with-jib, localhost:5000/my-image:tag2, and localhost:5000/my-image:latest
Runs by calling java -Dmy.property=example.value -Xms512m -Xdebug -cp app/libs/*:app/resources:app/classes mypackage.MyApp some args
Exposes port 1000 for tcp (default), and ports 2000, 2001, 2002, and 2003 for udp
Has two labels (key1:value1 and key2:value2)
Is built as OCI format

jib {
  from {
    image = 'openjdk:alpine'
  }
  to {
    image = 'localhost:5000/my-image/built-with-jib'
    credHelper = 'osxkeychain'
    tags = ['tag2', 'latest']
  }
  container {
    jvmFlags = ['-Dmy.property=example.value', '-Xms512m', '-Xdebug']
    mainClass = 'mypackage.MyApp'
    args = ['some', 'args']
    ports = ['1000', '2000-2003/udp']
    labels = [key1:'value1', key2:'value2']
    format = 'OCI'
  }
}

Setting the Base Image

There are three different types of base images that Jib accepts: an image from a container registry, an image stored in the Docker daemon, or an image tarball on the local filesystem. You can specify which you would like to use by prepending the jib.from.image configuration with a special prefix, listed below:

Prefix	Example	Type
None	`openjdk:11-jre`	Pulls the base image from a registry.
`registry://`	`registry://eclipse-temurin:11-jre`	Pulls the base image from a registry.
`docker://`	`docker://busybox`	Retrieves the base image from the Docker daemon.
`tar://`	`tar:///path/to/file.tar`	Uses an image tarball stored at the specified path as the base image. Also accepts relative paths (e.g. `tar://build/jib-image.tar`).

Adding Arbitrary Files to the Image

You can add arbitrary, non-classpath files to the image without extra configuration by placing them in a src/main/jib directory. This will copy all files within the jib folder to the target directory (/ by default) in the image, maintaining the same structure (e.g. if you have a text file at src/main/jib/dir/hello.txt, then your image will contain /dir/hello.txt after being built with Jib).

Note that Jib does not follow symbolic links in the container image. If a symbolic link is present, it will be removed prior to placing the files and directories.

You can configure different directories by using the jib.extraDirectories.paths parameter in your build.gradle:

jib {
  // Copies files from 'src/main/custom-extra-dir' and '/home/user/jib-extras' instead of 'src/main/jib'
  extraDirectories.paths = ['src/main/custom-extra-dir', '/home/user/jib-extras']
}

Alternatively, the jib.extraDirectories parameter can be used as a closure to set custom extra directories, as well as the extra files' permissions on the container:

jib {
  extraDirectories {
    paths = 'src/main/custom-extra-dir'  // Copies files from 'src/main/custom-extra-dir'
    permissions = [
        '/path/on/container/to/fileA': '755',  // Read/write/execute for owner, read/execute for group/other
        '/path/to/another/file': '644',  // Read/write for owner, read-only for group/other
        '/glob/pattern/**/*.sh': 755
    ]
  }
}

Using paths as a closure, you may also specify the target of the copy and include or exclude files:

  extraDirectories {
    paths {
      path {
        // copies the contents of 'src/main/extra-dir' into '/' on the container
        from = file('src/main/extra-dir')
      }
      path {
        // copies the contents of 'src/main/another/dir' into '/extras' on the container
        from = file('src/main/another/dir')
        into = '/extras'
      }
      path {
        // copies a single-file.xml
        from = 'src/main/resources/xml-files'
        into = '/dest-in-container'
        includes = ['single-file.xml']
      }
      path {
        // copies only .txt files except for 'hidden.txt' at the source root
        from = 'build/some-output'
        into = '/txt-files'
        includes = ['*.txt', '**/*.txt']
        excludes = ['hidden.txt']
      }
    }
  }

You can also configure paths and permissions through lazy configuration in Gradle, using providers in build.gradle:

extraDirectories {
   paths = project.provider { 'src/main/custom-extra-dir' }
   permissions = project.provider { ['/path/on/container/to/fileA': '755'] }
}

extraDirectories {
   paths {
     path { 
       from = project.provider { 'src/main/custom-extra-dir' }
       into = project.provider { '/dest-in-container' }
       includes = project.provider { ['*.txt', '**/*.txt'] }
       excludes = project.provider { ['hidden.txt'] }
    }
  }
}

Authentication Methods

Pushing/pulling from private registries require authorization credentials.

Using Docker configuration files

Jib looks from credentials from $XDG_RUNTIME_DIR/containers/auth.json, $XDG_CONFIG_HOME/containers/auth.json, $HOME/.config/containers/auth.json, $DOCKER_CONFIG/config.json, and $HOME/.docker/config.json.

See this issue and man containers-auth.json for more information about the files.

Using Docker Credential Helpers

Docker credential helpers are CLI tools that handle authentication with various registries.

Some common credential helpers include:

Google Container Registry: docker-credential-gcr
AWS Elastic Container Registry: docker-credential-ecr-login
Docker Hub Registry: docker-credential-*
Azure Container Registry: docker-credential-acr-*

Configure credential helpers to use by specifying them as a credHelper for their respective image in the jib extension.

Example configuration:

jib {
  from {
    image = 'aws_account_id.dkr.ecr.region.amazonaws.com/my-base-image'
    credHelper = 'ecr-login'
  }
  to {
    image = 'gcr.io/my-gcp-project/my-app'
    credHelper = 'gcr'
  }
}

Using Specific Credentials

You can specify credentials directly in the extension for the from and/or to images.

jib {
  from {
    image = 'aws_account_id.dkr.ecr.region.amazonaws.com/my-base-image'
    auth {
      username = USERNAME // Defined in 'gradle.properties'.
      password = PASSWORD
    }
  }
  to {
    image = 'gcr.io/my-gcp-project/my-app'
    auth {
      username = 'oauth2accesstoken'
      password = 'gcloud auth print-access-token'.execute().text.trim()
    }
  }
}

These credentials can be stored in gradle.properties, retrieved from a command (like gcloud auth print-access-token), or read in from a file.

For example, you can use a key file for authentication (for GCR, see Using a JSON key file):

jib {
  to {
    image = 'gcr.io/my-gcp-project/my-app'
    auth {
      username = '_json_key'
      password = file('keyfile.json').text
    }
  }
}

Custom Container Entrypoint

If you don't set jib.container.entrypoint, the default container entrypoint to launch your app will be basically java -cp <runtime classpath> <app main class>. (The final java command can be further configured by setting jib.container.{jvmFlags|args|extraClasspath|mainClass|expandClasspathDependencies}.)

Sometimes, you'll want to set a custom entrypoint to use a shell to wrap the java command. For example, to let sh or bash expand environment variables, or to have more sophisticated logic to construct a launch command. (Note, however, that running a command with a shell forks a new child process unless you run it with exec like sh -c "exec java ...". Whether to run the JVM process as PID 1 or a child process of a PID-1 shell is a decision you should make carefully.) In this scenario, you will want to have a way inside a shell script to reliably know the default runtime classpath and the main class that Jib would use by default. To help this, Jib >= 3.1 creates two JVM argument files under /app (the default app root) inside the built image.

/app/jib-classpath-file: runtime classpath that Jib would use for default app launch
/app/jib-main-class-file: main class

Therefore, for example, the following commands will be able to launch your app:

(Java 9+) java -cp @/app/jib-classpath-file @/app/jib-main-class-file
(with shell) java -cp $( cat /app/jib-classpath-file ) $( cat /app/jib-main-class-file )

Reproducible Build Timestamps

To ensure that a Jib build is reproducible, Jib sets the image creation time to the Unix epoch (00:00:00, January 1st, 1970 in UTC) and all file modification times to one second past the epoch by default. See the Jib FAQ for more details on reproducible builds.

Another, more complex way to achieve reproducible builds with stable creation times is to leverage commit timestamps from the project's SCM. For example, the gradle-git-properties plugin can be used to inject Git commit information into the current build. These can then be used to configure jib.container.creationTime. Since the actual Git information is not yet available at the time the build is configured, it needs to be set through lazy configuration in Gradle, using a provider in build.gradle:

jib {
   container {
     creationTime = project.provider { project.ext.git['git.commit.time'] }
   }
}

This would build an image with the creation time set to the time of the latest commit from project.ext.git['git.commit.time'].

Jib Extensions

The Jib build plugins have an extension framework that enables anyone to easily extend Jib's behavior to their needs. We maintain select first-party plugins for popular use cases like fine-grained layer control and Quarkus support, but anyone can write and publish an extension. Check out the jib-extensions repository for more information.

WAR Projects

Jib also containerizes WAR projects. If the Gradle project uses the WAR Plugin, Jib will by default use jetty as a base image to deploy the project WAR. No extra configuration is necessary other than using the WAR Plugin to make Jib build WAR images.

Note that Jib will work slightly differently for WAR projects from JAR projects:

container.mainClass and container.jvmFlags are ignored.
The WAR will be exploded into /var/lib/jetty/webapps/ROOT, which is the expected WAR location for the Jetty base image.

To use a different Servlet engine base image, you can customize container.appRoot, container.entrypoint, and container.args. If you do not set entrypoint or args, Jib will inherit the ENTRYPOINT and CMD of the base image, so in many cases, you may not need to configure them. However, you will most likely have to set container.appRoot to a proper location depending on the base image. Here is an example of using a Tomcat image:

jib {
  from.image = 'tomcat:8.5-jre8-alpine'

  // For demonstration only: this directory in the base image contains a Tomcat default
  // app (welcome page), so you may first want to delete this directory in the base image.
  container.appRoot = '/usr/local/tomcat/webapps/ROOT'
}

When specifying a jetty image yourself with from.image, you may run into an issue (#3204) and need to override the entrypoint.

jib {
  from.image = 'jetty:11.0.2-jre11'
  container.entrypoint = ['java', '-jar', '/usr/local/jetty/start.jar']
}

Skaffold Integration

Jib is an included builder in Skaffold. Jib passes build information to skaffold through special internal tasks so that skaffold understands when it should rebuild or synchronize files. For complex builds, the defaults may not be sufficient, so the jib extension provides a skaffold configuration closure which exposes:

Field	Type	Default	Description
`watch`	`watch`	None	Additional configuration for file watching
`sync`	`sync`	None	Additional configuration for file synchronization

watch is a closure with the following properties:

Field	Type	Default	Description
`buildIncludes`	`List<String>`	None	Additional build files that skaffold should watch
`includes`	`List<String>`	None	Additional project files or directories that skaffold should watch
`excludes`	`List<String>`	None	Files and directories that skaffold should not watch

sync is a closure with the following properties:

Field	Type	Default	Description
`excludes`	`List<String>`	None	Files and directories that skaffold should not sync

Need Help?

A lot of questions are already answered!

Frequently Asked Questions (FAQ)
Stack Overflow
GitHub issues

For usage questions, please ask them on Stack Overflow.

Privacy

See the Privacy page.

Upcoming Features

See Milestones for planned features. Get involved with the community for the latest updates.

Community

See the Jib project README.

Disclaimer

This is not an officially supported Google product.

Files

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