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1. USING AN AWS S3 BUCKET AS YOUR MAVEN REPOSITORY

An Amazon Web Services S3 bucket is an inexpensive option to store your Maven or other binary artifacts. It’s an alternative to feature-rich Maven repository managers like Nexus and Artifactory when you don’t have the resources to install and maintain a server with the required software or the budget to subscribe to a hosted plan.

One choice I wouldn’t recommend is to store the binary artifacts in the SCM.

Deploying a Maven snapshot artifact to an AWS S3 Bucket

This “how to” post covers configuring Maven and setting up an AWS S3 bucket to store deployed Java artifacts.

2. SETUP AWS S3 BUCKET

2.1. CREATE S3 BUCKET
  • Click on Services -> S3 -> Create Bucket. This tutorial uses Name=maven-repo-tutorial.asimio.net and Region=US East.

AWS S3 Bucket Name and Region Creating an AWS S3 Bucket to store Maven artifacts

  • Click Next a few times then Create bucket.
  • Create two folders in the bucket: release and snapshot.

Maven AWS S3 Bucket - release and snapshot folders Maven AWS S3 Bucket - release and snapshot folders

2.2. CREATE IAM POLICY
  • Click on Services -> IAM -> Policies -> Create policy and paste this policy in the JSON tab:
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "VisualEditor0",
      "Effect": "Allow",
      "Action": "s3:*",
      "Resource": [
        "arn:aws:s3:::maven-repo-tutorial.asimio.net",
        "arn:aws:s3:::maven-repo-tutorial.asimio.net/*"
      ]
    }
  ]
}

AWS IAM Policy - JSON Creating a AWS IAM Policy - JSON

  • Click on Review policy and Create policy to complete it. This tutorial uses Name=maven-repo-tutorial-policy.

AWS IAM Policy - Name and Service Creating an AWS IAM Policy - Name and Service

2.3. CREATE IAM USER
  • Click on Services -> IAM -> Users -> Add user. This tutorial uses User name=maven-repo-tutorial-user and Access type=Programmatic access, because this guide uses the Access Key ID and the Secret Access Key as the credentials.

AWS IAM User - Name and Access Type Creating an AWS IAM User - Name and Access Type

Attaching an AWS IAM Policy to an IAM User Attaching an AWS IAM Policy to an IAM User

  • Click on Review and Create user buttons and store the Access key ID and Secret access key pair associated the created user in a safe medium.

Now that the Amazon S3 bucket with corresponding permissions is ready, lets change a Java application.

3. CONFIGURING MAVEN AND APPLICATION TO BE DEPLOYED TO AN S3 BUCKET

Include these updates on the Maven and application side:

settings.xml:

...
<servers>
  <server>
    <id>maven-repo-tutorial.asimio.net</id>
    <username>${iam-user-access-key-id}</username>
    <password>${iam-user-secret-key}</password>
  </server>
</servers>
...

This change could be included in your existing ~/.m2/settings.xml or in a new file as done in this tutorial.

You could paste Access key ID and Secret access key into username and password elements directly, but please make sure this file is protected and/or the password is encrypted. Or you could pass these values via VM arguments -Diam-user-access-key-id=XXXX, -Diam-user-secret-key=XXXX.

Let’s configure the artifact’s pom.xml:

pom.xml:

<build>
...
  <extensions>
    <extension>
      <groupId>org.springframework.build</groupId>
      <artifactId>aws-maven</artifactId>
      <version>5.0.0.RELEASE</version>
    </extension>
  </extensions>
...
</build>
...
<distributionManagement>
  <snapshotRepository>
    <id>maven-repo-tutorial.asimio.net</id>
    <url>s3://maven-repo-tutorial.asimio.net/snapshot</url>
  </snapshotRepository>
  <repository>
    <id>maven-repo-tutorial.asimio.net</id>
    <url>s3://maven-repo-tutorial.asimio.net/release</url>
  </repository>
</distributionManagement>
...

Notice these ids match the one from settings.xml.

aws-maven is a Maven Wagon for AWS S3, used to publish artifacts to an S3 bucket.

And that’s it configuring a Maven application or module, let’s now deploy an artifact.

4. DEPLOYING AN ARTIFACT TO AN S3 BUCKET

4.1. DEPLOYING A SNAPSHOT
mvn --settings settings.xml clean deploy -Diam-user-access-key-id=XXXX -Diam-user-secret-key=XXXX
...
[INFO] --- maven-deploy-plugin:2.8.2:deploy (default-deploy) @ springboot-togglz-demo ---
Downloading: s3://maven-repo-tutorial.asimio.net/snapshot/com/asimio/demo/springboot-togglz-demo/0-SNAPSHOT/maven-metadata.xml
Uploading: s3://maven-repo-tutorial.asimio.net/snapshot/com/asimio/demo/springboot-togglz-demo/0-SNAPSHOT/springboot-togglz-demo-0-20180625.213032-1.jar
Uploaded: s3://maven-repo-tutorial.asimio.net/snapshot/com/asimio/demo/springboot-togglz-demo/0-SNAPSHOT/springboot-togglz-demo-0-20180625.213032-1.jar (15016 KB at 4756.2 KB/sec)
Uploading: s3://maven-repo-tutorial.asimio.net/snapshot/com/asimio/demo/springboot-togglz-demo/0-SNAPSHOT/springboot-togglz-demo-0-20180625.213032-1.pom
Uploaded: s3://maven-repo-tutorial.asimio.net/snapshot/com/asimio/demo/springboot-togglz-demo/0-SNAPSHOT/springboot-togglz-demo-0-20180625.213032-1.pom (3 KB at 2.1 KB/sec)
Downloading: s3://maven-repo-tutorial.asimio.net/snapshot/com/asimio/demo/springboot-togglz-demo/maven-metadata.xml
Uploading: s3://maven-repo-tutorial.asimio.net/snapshot/com/asimio/demo/springboot-togglz-demo/0-SNAPSHOT/maven-metadata.xml
Uploaded: s3://maven-repo-tutorial.asimio.net/snapshot/com/asimio/demo/springboot-togglz-demo/0-SNAPSHOT/maven-metadata.xml (775 B at 0.6 KB/sec)
Uploading: s3://maven-repo-tutorial.asimio.net/snapshot/com/asimio/demo/springboot-togglz-demo/maven-metadata.xml
Uploaded: s3://maven-repo-tutorial.asimio.net/snapshot/com/asimio/demo/springboot-togglz-demo/maven-metadata.xml (293 B at 0.3 KB/sec)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
...

Deploying a Maven snapshot artifact to an AWS S3 Bucket Deploying a Maven snapshot artifact to an AWS S3 Bucket

4.2. DEPLOYING A RELEASE
mvn clean versions:set -DnewVersion=1.0.1
...
[INFO] Processing com.asimio.demo:springboot-togglz-demo
[INFO]     Updating project com.asimio.demo:springboot-togglz-demo
[INFO]         from version 0-SNAPSHOT to 1.0.1
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
...

This command updates the version of the artifact.

mvn --settings settings.xml clean deploy -Diam-user-access-key-id=XXXX -Diam-user-secret-key=XXXX
...
[INFO] --- maven-deploy-plugin:2.8.2:deploy (default-deploy) @ springboot-togglz-demo ---
Uploading: s3://maven-repo-tutorial.asimio.net/release/com/asimio/demo/springboot-togglz-demo/1.0.1/springboot-togglz-demo-1.0.1.jar
Uploaded: s3://maven-repo-tutorial.asimio.net/release/com/asimio/demo/springboot-togglz-demo/1.0.1/springboot-togglz-demo-1.0.1.jar (15016 KB at 2167.7 KB/sec)
Uploading: s3://maven-repo-tutorial.asimio.net/release/com/asimio/demo/springboot-togglz-demo/1.0.1/springboot-togglz-demo-1.0.1.pom
Uploaded: s3://maven-repo-tutorial.asimio.net/release/com/asimio/demo/springboot-togglz-demo/1.0.1/springboot-togglz-demo-1.0.1.pom (3 KB at 1.9 KB/sec)
Downloading: s3://maven-repo-tutorial.asimio.net/release/com/asimio/demo/springboot-togglz-demo/maven-metadata.xml
Uploading: s3://maven-repo-tutorial.asimio.net/release/com/asimio/demo/springboot-togglz-demo/maven-metadata.xml
Uploaded: s3://maven-repo-tutorial.asimio.net/release/com/asimio/demo/springboot-togglz-demo/maven-metadata.xml (317 B at 0.2 KB/sec)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
...

Deploying a Maven release artifact to an AWS S3 Bucket Deploying a Maven release artifact to an AWS S3 Bucket

It could be seen both, a snapshot and a release artifacts were successfully deployed to an S3 bucket.

Similarly to deploying an artifact, Maven applications can be configured to fetch dependencies from an S3 bucket.

This solution would be valid for a solo developer or a small team. Although a better choice than checking in the resulting artifacts into the SCM, it has some limitations. You won’t be able to Search for an artifact, which is convenient when you need to find out the artifactId, groupId and version of a dependency. Another limitation is maintenance. As the snapshot folder grows overtime, you would have to manually remove older versions.

A solution to these problems could be automated when using a feature-rich Maven repository manager like Nexus or Artifactory but as mentioned in the Introduction, it would also require more effort to set it up and a running server or a subscription to a paid plan.

Thanks for reading and as always, feedback is very much appreciated. If you found this post helpful and would like to receive updates when content like this gets published, sign up to the newsletter.

5. REFERENCES