This document is intended to be kept up to date by the DSpace Release Team. It details the steps necessary to perform snapshot and official releases of DSpace and supporting Modules.
Useful Sonatype Links
For lack of a better place at this time, here's some useful pages on Sonatype which detail the Sonatype Maven Release Process:
Release Numbering Convention
As of 2012 (DSpace 3.0), DSpace has moved to a new release numbering scheme/format. Release numbers will now only consist of two numbers.
Release Numbering Scheme:
[major].[minor] (e.g. 3.0, 3.1, 3.2, 4.0)
- Major Releases: incrementing the first number ('major') will represent a new MAJOR release of DSpace. A major release may include any or all of the following: new features, system improvements, architectural changes, bug fixes. All major releases end in ".0", so "3.0", "4.0", and "5.0" would all represent major releases.
- Minor (Bug-Fix) Releases: incrementing the second number ('minor') will represent a new MINOR release of DSpace. A minor release will only include bug fixes to an existing major release. For example, "3.1" and "3.2" would represent two minor releases which only include bug fixes to the "3.0" major release..
Small Exception for Language Packs Releases
The one exception is that the Language Packs (
dspace-xmlui-lang) use the numbering convention
[major].[minor].[sequence-number] (e.g. 3.0.0, 3.0.1, 3.1.0, etc.). This allows us to release new versions of the language packs more frequently than normal DSpace releases, as needed.
Verify Release Privileges
To perform a release, you must have all of the following:
- Write access to the DSpace GitHub repository hosted at https://github.com/DSpace/DSpace. (All Committers should already have this, obviously)
- Write access to the org.dspace groupId in the snapshot and staging repositories hosted at oss.sonatype.org. If you don't already have this, you will need to:
- Sign up for a Sonatype JIRA account. This account will also serve as your login to the Sonatype OSS system. (If you already have a Sonatype account, you can skip this step)
- Ask a Committer with release privileges (e.g. a previous release manager) to request that your Sonatype account be given release privileges to the "org.dspace" GroupID. This request should be submitted via the Sonatype JIRA system in the Open Source Project Repository Hosting project.
- Once Sonatype gives you the proper authorization, you should be able to login to the Sonatype OSS system using the same login/password you setup in Sonatype JIRA. You should also have access to publish new releases to the "org.dspace" GroupID.
- NOTE: The full details of signing up and getting access to Sonatype are also posted online here: Sonatype Maven Repository Usage Guide
- You must generate and publish your own personal Code Signing Key (required by Sonatype). Here are two sites that give hints on how to do that:
- Creating a Code Signing Key
- How to Generate PGP Signatures with Maven (required for all Sonatype releases)
- Make sure to publish your Key file to
hkp://pgp.mit.edu, as this is the Key Server Sonatype uses for verification:
gpg --keyserver hkp://pgp.mit.edu --send-keys [yourKeyID]
[yourKeyId]can be found by running the following command and copying the alpha-numeric string after the "/" on the "pub" line
- You can see if your key is already on that Key Server by visiting http://pgp.mit.edu and searching on your name
Update Maven settings.xml
DSpace's root pom.xml already has the correct staging and snapshot repositories listed in the OSS parent's '<distributionManagement>' section. In order to deploy, you will need to add your Sonatype OSS username and password to your local
~/.m2/settings.xml file. For example:
If you don't yet have a
~/.m2/settings.xml file, you should create one, and copy the full contents above (obviously make sure to put in your username and password).
Maven settings to release DSpace < 6
With DSpace 6 we changed the maven plugin that pushes our releases to Sonatype. The configuration above is correct beginning with DSpace 6. In case you release a previous DSpace version, you'll need to copy the server section two times and change the id to
A settings file that allows you to release all versions of DSpace would look like the following example:
While it may look surprisingly that you have to add the same credentials three times, DSpace < 6 will be looking for these server IDs and the upload to sonatype will fail as unauthorized if they are missing.
Using SSH and GPG agents
During a release you have to type the passwords of your GPG and SSH keys very often. Every DSpace module produces several files, all have to be signed and transfered to Sonatype. GPG and SSH agents help you to avoid typing passwords again and again. To use an ssh-agent just start it, export the required environment variables and add your ssh-key. To use a gpg agent start it, export the required environment variables and add the following to your
Obviously, that should be outside of the
<servers> tags but included within the
<settings> tags. On each maven run it may ask you once about your password which is a big improvement.
For DSpace 6, you can use either Java 7 or Java 8 for the release.
Use Maven 3 or above
Make sure you're using a recent version of Maven. As of this writing, Maven 3.0.5 is known to work.
For more information see the Prerequisites section of the Sonatype Maven Repository Usage Guide
Unset MAVEN_OPTS, if you use it
If you normally use a MAVEN_OPTS environment variable on the machine you're using to cut the release, be sure to unset it, with this command:
It's highly unlikely the configuration in your MAVEN_OPTS will be useful for the release. It's highly likely to cause problems. Better to be safe.
Making a Snapshot Release (e.g. 'dspace-x.y-SNAPSHOT')
One Step Process
From a clean, up-to-date copy of master/branch, run the following command:
mvn clean javadoc:jar source:jar deploy
You will have to enter in your GPG passphrase (which you established when you created your Code Signing Key).
The snapshot will be immediately available in the public Sonatype repository: http://oss.sonatype.org/content/groups/public
Releasing a Single Module/Project
- If you'd like to release a Snapshot Release of that module, follow the instructions at: Making a Snapshot Release (e.g. 'dspace-x.y-SNAPSHOT')
- If you'd like to tag & release a new version of that module, use the module instructions at: Release DSpace Language Packs (I18N) Modules (NOTE: These instructions obviously have some specific notes around how the Language Packs modules are versioned. You obviously don't need to follow those versioning notes. Individual modules may have their own version schemes)
Making an Official Release (e.g. 'dspace-x.y' or 'dspace-x.y-rc1')
For More Information
These same steps are also covered in the Sonatype Maven Repository Usage Guide
Release DSpace Language Packs (I18N) Modules
Before performing an official release, you should see if the DSpace Language Packs (i18n modules) need an updated release. The easiest way to check if they need to be released it by checking to see if any commits have occurred since the previous release (see below for links). Please note that you can release these I18N Modules on the same day as the main DSpace release. The DSpace parent pom.xml is now configured to also check Sonatype's Release Repository for any Maven artifacts (so you do NOT need to wait for the I18N modules to appear in Maven Central)
At the moment the i18n modules are maintained in two separate GitHub projects. There are currently two i18n modules you will need to release:
dspace-api-lang- Check if any new commits have occurred on 'dspace-api-lang' since the last release.
dspace-xmlui-lang- Check if any new commits have occurred on 'dspace-xmlui-lang' since the last release.
Version Numbering Convention for Language Packs
Note that the version numbering convention for Language Packs is always the same as the current DSpace release, with an additional
.[sequence-number]. For example, the i18n modules for 3.0 were numbered as follows: 3.0.0, 3.0.1, etc.
Older Branches Do Not Update Language Packs
Language pack updates are not back-ported. If you are making a security release for an older branch of DSpace, there will be no language pack commits to release. Continue with Final Commits & Preparation, below.
For each module, perform the full release steps that follow. To save space, the steps are only listed for one of the modules (but don't forget to run it for both language packs):
- Checkout the Language Pack Module:
git clone git
git checkout masterNOTE: always release language packs from the master branch -- we do not use a maintenance branch for language packs.
- Do a Dry Run:
mvn release:prepare -DdryRun=true
- Tag and Increment Version:
mvn release:prepare -Dresume=false
- Make sure to assign a version number of the format:
[major].[minor].[sequence-number](e.g. 5.0.0, 5.0.1, etc for 5.0 releases of language packs)
- NOTE: The release process should suggest the correct version number by default
- Make sure to assign a version number of the format:
- Deploy Artifacts to Staging in Sonatype:
- Verify and Release Staged Artifacts in Sonatype (see instructions at link)
- Go back and run steps #1-5 above for the other language packs modules (dspace-xmlui-lang)
Once both Language Packs have been released, you can immediately perform the DSpace release. You do not need to wait for them to appear in Maven Central, as our DSpace parent pom.xml will find them in Sonatype's Release Repository immediately.
Final Commits & Preparation
Double Check Language Packs' Version Ranges
NOTE: if you're skimming these instructions, you may be tempted to think you've already handled this step, because you have already released new language packs, as detailed above. If you think so, you probably have NOT yet completed the steps below. The steps below tell DSpace what version of language packs to use. The language packs you've released following the steps above won't ever get used if you don't do the steps below. This is an easy thing to miss. Don't. Just check, to be sure.
Once the Language Packs are released, you will probably need to modify the DSpace root pom.xml (https://github.com/DSpace/DSpace/blob/master/pom.xml) to reference the new version of the Language Packs. This should be similar to the following:
If possible, you'd only want to commit this after the i18n modules are available in the Maven Repository. But, if you are in a rush, you can commit this change earlier (though be warned that this will break the build process for anyone who hasn't manually installed the i18n modules to his/her local
In the main pom.xml, provide the proper version range for each language pack. In the below example, we are saying to use any language pack version which is at least version 3.0.0, but is less than version 4.0.0:
Ensure Documentation is Updated Appropriately
Hopefully, you've already been talking with others about getting Documentation updated!
You should also double check that the following "main pages" are updated in the Documentation:
- Release Notes- Should contain a very basic overview of the Release. Make sure the Release number is updated here!
- NOTE: For minor releases (bug-fix-only releases), you may want to leave all information about the previous major release, and just enhance the content to state that this was a bug-fix release, and list any new contributors, etc.
- Installation - Obviously make sure the Installation Documentation is updated for this Release
- Upgrading a DSpace Installation - Same for the Upgrade Documentation, make sure it's up to date
- History- Make sure the online History for this latest Release is included. You should be able to just copy the last version's page and update the version numbers. For example, copy the previous release's page, and change as follows:
- You'll notice all the JIRA history is generated via the
jiraissueplugin. In the
urlargument for that plugin, you should find the DSpace version number embedded in the querystring like: "... AND+fixVersion+%3D+%223.0%22 ..." If you look closely, you'll see the 'fixVersion' is set to "3.0" in that search string. All you should need to do is update that version number (and the plugin will now search for tickets closed for 4.0)
Also make sure to update the
titleargument for that
jiraissueplugin to list the proper version number information
Obviously, this is just a brief reminder of important areas of Documentation which always require updates. There's surely other areas, like Configuration section, which will require some updates for your release.
- You'll notice all the JIRA history is generated via the
Double Check Contents of all README (and similar) files in GitHub
This is time-consuming, don't leave this task to release day
On skimming these instructions, this might look like a small thing, but it is not. It is a big information management task. Ask for help in wrangling/verifying the license information, and, if at all possible, DO NOT leave this job for release day.
Make sure that the contents of all README, LICENSE, LICENSES_THIRD_PARTY, NOTICE files are up-to-date in GitHub. These files reside in [dspace-src]. If anything is out-of-date, make sure to update it and commit the proper changes before continuing.
Regenerate the LICENSES_THIRD_PARTY file
On completion, a new, updated version of the LICENSES_THIRD_PARTY file will be written to your source directory. Please double check this file or "git diff" it to see if the changes look reasonable. Here are some things to especially be on the lookout for:
- If any dependencies are listed with an "UNKNOWN" license, then that means that dependency failed to specify its OS License in their own Maven POM file. We will need to manually lookup the license for that project, and manually add it to our
src/main/license/LICENSES_THIRD_PARTY.propertiesfile which corrects all "UNKNOWN" licenses. Finally, rerun the command above to regenerate the new LICENSES_THIRD_PARTY based on this update.
- If any dependencies are listed under an INCOMPATIBLE License (GPL, AGPL, etc), then we need to take a closer look at that dependency. It is possible that the dependency is dual-licensed and therefore may be listed multiple times in the generated LICENSES_THIRD_PARTY file. If so, that's fine. If not, we may need to remove that dependency prior to the release.
- If any Open Source Licenses are listed under multiple names (e.g. "BSD" vs. "BSD License" vs. "BSD licence"), then we may need to update our POM configurations for the codehaus license-maven-plugin to tell it to merge licenses of those names into one. Those configurations are in the Parent POM under the
<licenseMerges>tag of this plugin: https://github.com/DSpace/DSpace/blob/master/pom.xml#L406
Ensure you tag multiple releases in chronological order!
If you are performing multiple releases at once (e.g. backporting security or bug fixes), it is IMPORTANT to tag your releases chronologically. For example, the backported fixes to 3.x should be tagged BEFORE 4.x which should be tagged BEFORE 5.x. The reason for this is that the timestamp of the tag determines the ORDERING of the releases in GitHub. So, in order for the 5.x release to appear after the backported releases, it needs to be released LAST. The last tagged release will become the "Latest Release" in GitHub.
Warning: optional profiles need to be specified at compile time
Just including a little warning about this up front. The following optional modules need to be specified with every mvn command below. We will make an effort to keep this list up to date, but you should verify it before you cut a new release. Things change. Forgetting an optional module means you'll have to cut another release.
Checkout Master or Branch to Release
Checkout a fresh copy of the to-be-released version either from a branch or master. For example:
Note: do not just re-use an old working copy of the DSpace Master branch, for obvious reasons, you don't want your own work in progress sneaking into the release. It's also important to use the SSH repository path as noted above (NOT the https URL), otherwise you will be prompted for your GitHub credentials during the release process. More than once. Save yourself some time, be sure to use the SSH path.
Note: if you are doing a maintenance release, you will need to check out the maintenance branch, and not the master branch. In this case, the example above would instead read:
Update your Local Maven Cache (optional - may not be needed)
Before starting the release, you may wish to ensure your local maven cache (
~/.m2/repository) is completely up-to-date by running (from
Updating your local maven cache will help to ensure that the release process goes more smoothly, and should help you to avoid any errors having to do with Maven being unable to locate any particular dependencies. That being said, this step actually may not be necessary, if our release process is working correctly.
Do a sanity check of the tests
You know, just to save yourself a bunch of embarrassment later, run the tests?
Do a Dry Run
This step is not required, but performs a useful sanity check without committing any changes. From your clean, up-to-date copy of master/branch, run the following command (from
You will have to enter in your GPG passphrase (which you established when you created your Code Signing Key).
If you notice an issue or an error occurs, you can re-run the Dry Run using the following command:
mvn release:prepare -DdryRun=true -Dresume=false -Dmirage2.on=true
You can also clean up any of the release files that the Dry Run created, and just re-run it.
mvn release:prepare -DdryRun=true -Dmirage2.on=true
Tag and Increment Version
This step will set the version declared in the project's pom.xml files, commit the changes to master/branch, tag the release, and finally, check in the master/branch change that increments the next development version (e.g. x.y-SNAPSHOT) in the pom.xml files. Run the following (from
(Optionally, you may also include the parameters
-Dusername=YourGitHubUsername -Dpassword=YourGitHubPassword at the end of the above command, though I've not found these to be necessary)
The above command will ask you three basic questions. Here are sample answers for DSpace 3.0:
You will also have to enter in your GPG passphrase (which you established when you created your Code Signing Key).
Many JavaDoc WARNING messages will scroll by
As the release process scrolls by, you likely will see a LOT of "WARNING" messages. Don't worry, these should be just Javadocs warnings, and can be safely ignored. Just be patient, and see if it all succeeds in the end. We know it's nerve-wracking, but it will all be OK.
What do successful tagging results look like?
Assuming everything worked right, you should see ALL the following changes in GitHub:
- A newly tagged version of DSpace under: https://github.com/DSpace/DSpace/tags
- For example, if you are releasing "3.2" you should see a newly listed tag "dspace-3.2" in the list of tags above.
- The primary "pom.xml" file in that newly tagged version should have a <version> tag that correspond to the newly released version.
- For example, if you are releasing "3.2", then the "dspace-3.2" tag's main "pom.xml" should have a <version>3.2</version> tag
- The primary "pom.xml" file in the original branch ("master" or a ".x" branch) should now be updated to the next SNAPSHOT version
- For example, if you are releasing "3.2", then the original "dspace-3.x" branch's pom.xml file should now have a <version>3.3-SNAPSHOT</version> tag
The results from Maven look similar to this. (Don't worry about the "SKIPPED" messages, those are normal, as the actual release process just runs from the "DSpace Parent Project")
What to do if you get tagging Errors?
If you receive a project dependency error
mvn release:prepare command may fail to compile part way through the process, complaining that an internal project dependency is not met. If this occurs, don't worry. You just may need to ensure those dependencies get installed to your local cache. To fix this, you should be able to run the following:
mvn release:clean(clean out any files created by the previous "mvn release:prepare")
mvn install -Dmirage2.on=true
mvn release:prepare -Dmirage2.on=true
Backing out of changes
If backing out of this step is needed for any reason, the following will restore the github repository and your working copy to the state it was previously in:
- Warning: running a "mvn release:rollback" will perform an immediate, automatic push to GitHub master, rolling back any previously committed POM version changes.
- If you want to avoid the immediate, automatic push to GitHub master, you may be able to use "
mvn release:clean" to just clean up the locally made release preparations.
- Now delete the tag in GitHub (local & remote)
git tag -d dspace-x.y
git push origin :refs/tags/dspace-x.y
Deploy Artifacts to Staging in Sonatype
This step will sign, checksum, and push all release artifacts (including javadocs and sources) to the Sonatype staging repository (http://oss.sonatype.org/). Run the following (from
You should be prompted by Maven to specify your GPG passphrase (which you established when you created your Code Signing Key). If you run into any issues, it's possible to specify your GPG key and passphrase as arguments to the above command (e.g.
If upload to sonatype stalls
In case the upload to sonatype seems to be stalled, be patient. Maven will wait for a timeout and automatically retry the upload.
If you need to re-deploy
If any errors or problems occur during the deploy, you can re-run
mvn release:perform -Dmirage2.on=true safely after fixing those issues (re-running it will just overwrite existing staged contents).
If you run into issues, or need to perform the
mvn release:perform from a different machine, it is possible to run it simply against the created tag in GitHub.
Create a "dummy"
[src]/release.propertiesfile in your local DSpace source directory. It should simply state the basic SCM info for the tag you wish to release, e.g.
- Run the specified
mvn release:performcommand (see above). Maven will then proceed to checkout the specified tag into your
[src]/target/checkoutfolder, package up the release and send it off to Sonatype.
Verify and Release Staged Artifacts in Sonatype
For screenshots and more details on this step, visit the Sonatype Repository Usage Guide's section on Releasing your artifacts
- Login to http://oss.sonatype.org/
- Click "Staging Repositories" in the left column, then select the checkbox next to the staged repository on the right. The contents of it will open up at the bottom of the page.
- The staged repository should begin in the "Closed" state, which means some automated verifications on the POM structure etc. have already been run. If it is not yet closed, select it and click the "Close" button.
Ensure that the artifacts in staging are exactly as they should be once deployed to Maven Central. Here's a few things to watch out for...
Download one (or more) of the POMs, and make sure the
<version>tag is correct (e.g. 6.0 and not a SNAPSHOT version or similar)
Compare it against a past release in Maven Central (http://repo2.maven.org/maven2/org/dspace/), making sure it has the same JARs or WARs, etc
- Check if the file sizes looks reasonable (0 Bytes is probably not reasonable ;-)). You can also compare those to previous releases.
You can also verify the checksums of one or more of the JARs/WARs in Sonatype versus those that were installed into your
.m2directory. They should be the same.
If You Need to Revert Back before Releasing
If anything is incorrect, select the staged repository and select "Drop". After the problem is resolved, you can re-deploy the artifacts to staging and verify them again. To re-deploy an already-tagged release:
mvn release:perform -Dmirage2.on=true -Dtag=dspace-x.y -DconnectionUrl=scm:git:firstname.lastname@example.org:DSpace/DSpace.git -Darguments="-Dgpg.keyname=YourKeyId -Dgpg.passphrase=YourKeyPassword"
Once Released, There is No "Undo" Option
Once you select "Release", there is no way to "undo" the release. If any major issues are found, you'll have to increment the version number and perform a new bug-fix release.
Create the Distribution Zips
The previous actions will have checked out the release tag into the target directory under
[dspace-src]/target/checkout/dspace/. Navigate to that directory and execute the creation of the distributions using the following command. This will create two zip, bzip and gzipped files in the target directory. One set of files is the "binary" release, and the other set is the source release.
What if I deleted the 'target' or need to redo these distribution zips?
If you've already removed the
target/checkout directory, you can also checkout a fresh copy of the newly tagged version and run this command from the
# Checkout the 'dspace-5.1' tag into a new branch named dspace-5.1
git checkout dspace-5.1 -b dspace-5.1
# Then run the 'mvn package -Pdistributions' command as shown below
Create the PDF version of Wiki Documentation
Export the latest Wiki-based Documentation as PDF.
How to Generate PDF Documentation
See this DSpace documentation management guide: How To Export Downloadable Docs from Wiki
Create a new GitHub release & upload distribution files
- From the GitHub UI, visit: https://github.com/DSpace/DSpace/tags
- Find the newly tagged release & click on "Add Release Notes"
- Add in some basic release notes (refer to prior versions for some standard text). Please be sure to provide the following information:
- A link to the Wiki Release Notes (in the DSDOC area)
- A link to the general documentation for this release (again in the DSDOC area)
- Upload the distribution files and a PDF export of the documentation. There should be 5 total files attached:
- When you are satisfied, publish the new release!
After the Release is Finished
Don't Announce Until Maven Packages Have Propagated
You must wait for all the packages to be available at http://repo2.maven.org/maven2/org/dspace/ before you announce the release. Until the DSpace packages are available in the Maven repository, no one else will be able to build DSpace using Maven.
- Add the new contributors to the list: DSpaceContributors
- Coordinate Announcements with DuraSpace Staff:
- You might send draft announcements to the dspace-release mailing list for review.
- Announcement on dspace.org, duraspace.org, twitter
- Ensure that the Latest Release page on dspace.org is updated.
- Plus, ask dspace.org admins to upload latest documentation in PDF/HTML format
- Announce on all DSpace mailing lists
- Link announcement on Home of DSpace Wiki, change any version numbers listed on that page.
- Update Wiki pages, particularly these pages which refer to the Current and Next Releases:
- Also, update the Documentation Wiki area! Specifically:
- All Documentation page -> Has current release info
- Add a warning to the documentation of the newest unsupported release (e.g. the warning for DSpace 1.7) and link to our Support Policy.
Spaces - Space directory - (i) next to the space - Space Admin - Themes - Configure Theme - Header
- Homepage for the current Documentation (e.g. DSpace 4.x Documentation) -> Has links to download latest version of DSpace
- Update the database schema diagram
- For major releases, create a new branch in GitHub for any upcoming bug-fix releases:
- E.g., after the 3.0 release, we created a 3.x branch for any subsequent bug fix releases.
- To automatically create a branch, you may be able to use the release:branch command (NOTE: untested, but it should work! once we test it out, this may be the best practice way of creating a branch).
To manually create a branch, run commands similar to:
Then, go back to your
mastercheckout, and make sure to update its version numbers in the pom.xml files by running the following:
(Remember to enter in the next appropriate major version number. E.g. After releasing 3.0,
mastershould be updated to "4.0-SNAPSHOT", while the new
3_xbranch should be at "3.1-SNAPSHOT")
- NOTE: the
update-versionscommand doesn't always work perfectly. You will want to try a complete rebuild of DSpace before committing anything, as it sometimes misses updating a few version numbers.
- Push your verified changes back to GitHub.
- You'll also need to ensure that all version numbers and the
<scm>section is appropriate in the pom.xml files of your new Branch. Remember, the
<scm>configurations should point at the branch, rather than back at
- Updates to JIRA:
- Move any uncompleted issues to the next DSpace version tag in JIRA.
- Ask a JIRA Administrator to close out the release in JIRA (this will ensure no new issues can be added to that release).
- Updates to GitHub: Move any uncompleted PRs to the next DSpace version tag.
- Find the number of contributors (helpful data for the announcement, you are drafting an announcement, right?): for bugfix releases, it's:
git shortlog -ns branch_name_goes_here ^master | wc -l
Possible Errors you may Encounter
"Could not find model file" error (with language packs)
If you encounter one of these errors when building/packaging DSpace:
FATAL ERROR: "Reason: Could not find the model file '../dspace-xmlui-lang'. for project unknown"
FATAL ERROR: "Reason: Could not find the model file '../dspace-api-lang'. for project unknown"
This is a known bug in Maven. The problem is that you likely have a 'dspace-xmlui-lang' or 'dspace-api-lang' folder at the same level as your [dspace-source] parent folder. Essentially, Maven located them and tried to add them into the build process (which it shouldn't have). The fix is to completely delete the "dspace-xmlui-lang" and "dspace-api-lang" folders, and try to rebuild DSpace.
Advice for future Release Coordinators
With a straight face assure the next Release Coordinator that "Maven is easy" and there is nothing to be afraid of, then put your feet up and open a beer.