Cloud Native SIG - Pluggable Storage

The current default approach of storing everything into the filesystem is the main reason why Jenkins does not fit the "Cloud Native" model, with features like HA, zero downtime, or pay per use. While there are plenty of plugins that implement parts of this vision, this becomes cumbersome to configure and a usability nightmare for users, as JEP-300 has pointed out. Going towards a model where cloud services are consumed where it makes sense, the overall complexity on operating Jenkins in a cloud or containerized environment is greatly reduced. Other related projects include Jenkins X and Jenkins Evergreen which would greatly benefit from a Cloud Native storage for Jenkins.

There are several clear areas open for improvement, which are summarized here and will be detailed in future documents. A mayor pain point is the usage of local disk as all-purpose storage, which causes issues running on containerized or distributed environments, requiring highly performant filesystems, and all the configuration pain like initial sizing and resizing with downtime. We believe that by using cloud provided services the overall usability, performance and scalability can be improved while enabling new demanded functionality.

You can find more information about Pluggable Storage and priorities in this blogpost. Full list of Jenkins Enhancement Proposals is provided on the Cloud Native SIG Page.

Status summary

Below you can find a summary of ongoing activities and their current status:

Type Status JEPs Comment

Artifacts

Available

JEP-202

Credentials

Available

N/A

Completed before the JEP process was introduced

Build logs

In progress

JEP-207, JEP-210, JEP-212

System logs

Available

N/A

Jenkins supports custom log appenders using standard java.util.logging configuration options.

Task logs

Not started

Storage of system logs and various tasks (e.g. agent connection or SCM polling)

Configurations

In progress

JEP-213

Test results

In progress

Coming soon

Code coverage results

In exploration

TBD

Runs

Not started

Storage of full run records in an external database

Jobs

Not started

Storage of Job configurations and job-specific metadata in an external database. Existing plugins like Jenkins Pipeline and JobDSL partially address this case by keeping configurations in SCM.

Fingerprints

Not started

The list above is not complete. Other storage types may be considered according to the feedback. You can find more information about Pluggable Storage and priorities in this blogpost.

Artifact Storage

There are many existing plugins allowing to upload and download artifacts from external storage (e.g. S3, Artifactory, Publish over SFTP, etc., etc.), but there are no plugins which can do it transparently without using new steps. In many cases the artifacts also get uploaded through master, and it increases load on the system. It would be great if there was a layer which would allow storing artifacts externally when using common steps like Archive Artifacts.

Jenkins 2.118+ offers an extended jenkins.util.VirtualFile API which allows implementing external artifact managers using the ArtifactManagerFactory extension point.

Implementation example(s):

Related JEPs:

Build Log Storage

Logs disk usage causes the same issues previously mentioned for artifacts. Plus a external focused log storage such as AWS CloudWatch Logs allows demanded features as centralized log management, log retention policies, advanced querying, etc. There are already options to externally ship the logs to a backend, or plugins that would do that like the aws-cloudwatch-logs-publisher-plugin, but there is no integrated way to both send and display logs from external log storage. The External log storage work is tracked as issue:38313[].

Reference implementation(s):

Related JEPs:

Configuration Storage

Although configurations are not big, externalizing them is a critical task for getting highly-available or disposable Jenkins masters. There are many ways to store configurations in Jenkins, but 95% of cases are covered by the XmlFile layer which serializes objects to disk and reads them using the XStream library. Externalizing these XmlFiles would be a great step forward.

There are several prototypes for externalizing configurations, e.g. in DotCI. There are also other implementations which could be upstreamed to the Jenkins core.

Related JEPs:

Credentials

In Credentials Plugin 1.15+ there is a CredentialsProvider extension point which allows referencing and resolving external credentials. This engine allows implementing external credentials for plugins implementing Credentials API..

Implementation example(s):

Other credentials API in Jenkins (like jenkinsdoc:hudson.util.Secret) are not supported.

Test results

In common CI/CD use-cases a lot of the space is being consumed by test reports. This data is stored within JENKINS_HOME, and the current storage format requires huge overheads when retrieving statistics and, especially, trends. In order to display trends, each report has to be loaded and then processed in-memory.

The main purpose of externalising Test Results is to optimize Jenkins logic by querying the desired data from specialized external storages, e.g. from Document-based databases like Elasticsearch. According to the current plan, JUnit Plugin will be extended in order to support such external storage in its APIs being widely used by test reporting plugins.

Status:

Other Pluggable storage stories

This page summarizes statuses of the ongoing work only. There are other Pluggable Storage stories we consider in the Cloud Native SIG. See the SIG’s page for more details and links.