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How to prepare an Apache Release

This article introduces how to the Apache publish content and process

Understanding the Apache Release Cycle

In general, Source Release is the key and the required content of Apache. But Binary Release is optional, Dubbo can choose whether to release binary packages to the Apache repository or to the Maven central repository.

Please refer to the following links for more information on ASF’s release guide:

Preparation of Local Building Environment

Mainly including the related preparation of signature utilities and Maven repository certification

  1. Install GPG,refer to

    • For example, in Mac OS
    $ brew install gpg
    $ gpg --version #check version,should be 2.x
  2. Generate the key with GPG

    • Generate the key according to the prompt
    $ gpg2 --full-gen-key
    gpg (GnuPG) 2.0.12; Copyright (C) 2009 Free Software Foundation, Inc.
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.
    Please select what kind of key you want:
      (1) RSA and RSA (default)
      (2) DSA and Elgamal
      (3) DSA (sign only)
      (4) RSA (sign only)
    Your selection? 1
    RSA keys may be between 1024 and 4096 bits long.
    What keysize do you want? (2048) 4096
    Requested keysize is 4096 bits
    Please specify how long the key should be valid.
            0 = key does not expire
         <n>  = key expires in n days
         <n>w = key expires in n weeks
         <n>m = key expires in n months
         <n>y = key expires in n years
    Key is valid for? (0) 
    Key does not expire at all
    Is this correct? (y/N) y
    GnuPG needs to construct a user ID to identify your key.
    Real name: Robert Burrell Donkin
    Email address:
    You selected this USER-ID:
       "Robert Burrell Donkin (CODE SIGNING KEY) <>"
    Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? O
    You need a Passphrase to protect your secret key. # enter the password, which will be used frequently when packaging.
    • View key id
    $ gpg --list-keys
    pub   rsa4096/28681CB1 2018-04-26 # 28681CB1 is the key id
    uid       [ultimate] liujun (apache-dubbo) <>
    sub   rsa4096/D3D6984B 2018-04-26
    ########### Note: Different diaplay for different version.
    $ gpg --list-keys
    pub   rsa4096 2018-11-12 [SC]
          63AAE9838F4A303E40BAF5FEA3A1CA7A5D4A3981     # Last 8 character(5D4A3981) as key id,it will be used when send public key to keyserver
    uid           [ 绝对 ] Victory Cao (CODE SIGNING KEY) <>
    sub   rsa4096 2018-11-12 [E]
    # send public key to keyserver via key id 
    $ gpg --keyserver --send-key 28681CB1
    # Here is a random selection of keyserver. Any key server from the list is acceptable because they are automatically synchronized.
    • If there are multiple public keys,you can set the default key


    # If you have more than 1 secret key in your keyring, you may want to
    # uncomment the following option and set your preferred keyid.
    default-key 28681CB1
    • If there are multiple public keys, you can also delete unuseful key:
    ### Delete the private key first, then delete the public key.
    $ gpg --yes --delete-secret-keys   ### indicate email address  
    $ gpg --delete-keys 1808C6444C781C0AEA0AAD4C4D6A8007D20DB8A4 
  3. Set up Apache central repository.

    • The parent pom of Dubbo project is apache pom
       <!-- To publish a snapshot of some part of Maven -->
         <username> <!-- YOUR APACHE LDAP USERNAME --> </username>
         <password> <!-- YOUR APACHE LDAP PASSWORD (encrypted) --> </password>
       <!-- To stage a release of some part of Maven -->
         <username> <!-- YOUR APACHE LDAP USERNAME --> </username>
         <password> <!-- YOUR APACHE LDAP PASSWORD (encrypted) --> </password>
         <!-- gpg passphrase used when generate key -->
         <passphrase><!-- yourKeyPassword --></passphrase>

Pack & Upload

  1. Pull the new branch from the master branch as the release branch. If you want to release the ${release_version} version now, pull the new branch ${release_version}-release from 2.6.x. Then the modifications and taggings related to ${release_version} Release Candidates are applied to ${release_version}-release branch, and is merged into the master branch after the final release.

  2. First of all, verify that the maven component packing, source packing, signature, etc are working properly on the ${release_version}-release branch.

    $ mvn clean install -Papache-release
    $ mvn deploy

This push the snapshot package to the maven central repository.

  1. Release with maven-release-plugin

    • verify with dryRun
    $ mvn release:prepare -Prelease -Darguments="-Dmaven.test.skip=true" -DautoVersionSubmodules=true -Dusername=YOUR GITHUB ID -DdryRun=true
    • After verification, run release:prepare
    $ mvn release:clean
    $ mvn release:prepare -Prelease -Darguments="-Dmaven.test.skip=true" -DautoVersionSubmodules=true -Dusername=YOUR GITHUB ID -DpushChanges=false

    If you are promted to input password for pushing to GitHub (basically including adding new commits and tags), do not input your login password of GitHub. Use Personal access tokens instead. You can go to, click Developer settings -> Personal access tokens, and generate a new token if not. Please refer to this guide for more infomation. you need to choose the release artifactId, next artifactId and the release tag, the default tag is dubbo-parent-xxxx, you need to change it to dubbo-xxxx

    After executing the above commands, you will find that:

    1. and are generated under dubbo-distribution directory, please unzip it and check the file structure
    2. -DpushChanges=false tells maven not to push the commits and tags to the remote repostiroy. If not specified, the version tag will be pushed to github repository, you will see a commit called [maven-release-plugin] prepare release dubbo-x.x.x added.
    3. The branch version is upgraded to ${release_version+1}-SNAPSHOT automatically. If -DpushChanges=true is specified, the modifications will be pushed to the remote repository, you will see a commit called [maven-release-plugin] prepare for next development iteration added.

    If -DpushChanges=false is specified, you will have to manually push the commit to remote repository before go to next step.

    • Run release:perform
    $ mvn release:perform -Prelease -Darguments="-Dmaven.test.skip=true" -DautoVersionSubmodules=true -Dusername=YOUR GITHUB ID

    Maven will download the source code from the tag you just pushed, compile it, and deploy to remote maven repsoitry in staging state.


When you deploy the package into repository, it will be interrupted for network. So you must restart to desploy.
The problem is that missing package occurred many times at deploying. So you should check the quantity of package, especially parent package.

Prepare Apache Release

  1. Prepare the svn local environment (Apache hosting the release content of project by svn)

  2. Checkout dubbo to local directory

    $ svn checkout

    Assume that the local directory is ~/apache/incubator/dubbo

  3. The current release version is ${release_version}, new directory

    $ cd ~/apache/incubator/dubbo # dubbo svn root directory
    $ mkdir ${release_version}
  4. Add public key to KEYS file if you are the first time to be a release manager. KEYS is mainly used to allow people who participate in the voting to be imported locally to verify the correctness of the sign.

    $ gpg -a --export your_key_id >> KEYS

    For more information on how to get your key id, please refer to this guide

  5. Copy the package from the Dubbo root directory to the svn local repository dubbo/${release_version}

  6. Generate sha512 sign


    $ shasum -a 512 apache-dubbo-${release_version} >> apache-dubbo-${release_version}


    Please add -b paramter when generating sha512 for, which indicates it is a binary file.

    $ shasum -b -a 512 apache-dubbo-${release_version} >> apache-dubbo-${release_version}

    You should generate something like this:

    b8f13d1df6d6c9a1facc72fafc00b2d22bea1e600517c507467d8fca2f776a7a3877101742da53114bfa629ca5b941eb4d9ef989de43f0833e2a794e7ccf5c8a *

    Note there is a * sign before the file name.

  7. If the binary release is accompanied with the source release. Run the following command in the dubbo-distribution module:

    $ mvn install

    Go to target directory, copy and to svn local repository dubbo/${release_version}, and refer to step 6 to generate sha512 sign.

  8. Commit to Apache svn

    $ svn status
    $ svn commit -m 'prepare for ${release_version} RC1'

Verify Release Candidates

A full check list can be found here

The verification link includes but is not limited to the following contents and forms:

Check signatures and hashes are good

check the sha512 sum

$ shasum -c apache-dubbo-${release_version}
$ shasum -c apache-dubbo-${release_version}

check the gpg signarure

If it’s your first time verify a release candidte, you should import public keys first.

 $ curl >> KEYS # download public keys to local directory
 $ gpg --import KEYS # import keys
 $ gpg —edit-key liujun
   > trust # type trust command

Now, you can verify signature with command

gpg --verify
gpg --verify

Check source release file content

Unzip apache-dubbo-${release_version} to the default directory and check the following:

  • Directory with ‘incubating’ in name apache-dubbo-${release_version}-source-release
  • DISCLAIMER exists
  • LICENSE and NOTICE exists and contents are good
  • All files and no binary files exist
  • All files has standard ASF License header
  • Can compile from source
  • All unit tests can pass
    mvn clean test # This will run all unit tests
    # you can also open rat and style plugin to check if every file meets requirements.
    mvn clean test -Drat.skip=false -Dcheckstyle.skip=false
  • Release candidates match with corresponding tags, you can find tag link and hash in vote email.
    • check the version number in pom.xml are the same
    • check there are no extra files or directories in the source package, for example, no empty directories or useless log files.
      diff -r rc_dir tag_dir
    • check the top n tag commits, dive into the related files and check if the source package has the same changes

Check binary distribution file content

Unzip apache-dubbo-${release_version} and check:

  • Check signatures are good
  • ‘incubating’ in name
  • LICENSE and NOTICE exists and contents are good

Note that if the binary distribution contains third party files, you may need to update LICENSE file by adding the 3rd party license files. If these dependency is Apache License 2.0, and it contains NOTICE file, you may also need to update NOTICE file as well.

Release vote

The voting is divided into two phases:

  1. Dubbo community votes and sends the voting email to After reviewing by community developers and winning 3 binding tickets that agree to release, you can go to the next stage of voting.
  2. Apache community votes and sends the voting email to After reviewing by Apache IPMC(Incubator PMC) members and winning 3 binding votes that agree to release, you will be allowed to release officially.

The mail template for Apache Dubbo vote:

Hello Dubbo Community,

This is a call for vote to release Apache Dubbo (Incubating) version 2.6.2.

The release candidates:

Git tag for the release:

Hash for the release tag:

Release Notes:

The artifacts have been signed with Key : 28681CB1, which can be found in the keys file:

The vote will be open for at least 72 hours or until necessary number of votes are reached.

Please vote accordingly:

[ ] +1 approve 
[ ] +0 no opinion 
[ ] -1 disapprove with the reason

The Apache Dubbo (Incubating) Team

The mail template for Apache Incubator vote:

Hello all,

This is a call for vote to release Apache Dubbo (Incubating) version 2.6.4.

The Apache Dubbo community has voted on and approved a proposal to release
Apache Dubbo (Incubating) version 2.6.4.

We now kindly request the Incubator PMC members review and vote on this
incubator release.

Apache Dubbo™  is a high-performance, java based, open source
RPC framework. Dubbo offers three key functionalities, which include
interface based remote call, fault tolerance & load balancing, and
automatic service registration & discovery.

Dubbo community vote and result thread:
A minor issue also can be found in the above thread.

The release candidates (RC1):

Git tag for the release (RC1):

Hash for the release tag:

Release Notes:

The artifacts have been signed with Key : 7955FB6D1DD21CF7, which can be
found in the keys file:

Look at here for how to verify this release candidate:

The vote will be open for at least 72 hours or until necessary number of
votes are reached.

Please vote accordingly:
[ ] +1 approve
[ ] +0 no opinion
[ ] -1 disapprove with the reason

The Apache Dubbo (Incubating) Team

The mail template to announce the vote result:

We’ve received 3 +1 binding votes and one +1 non-binding vote:

+1 binding, Ian Luo
+1 binding, Huxing Zhang
+1 binding, Jun Liu

+1 non-binding, Jerrick

I will create a new vote thread in Apache community now.

Best regards,
The Apache Dubbo (Incubating) Team

Official Release

When the release vote has passed,

  1. Add the release files to official release directory
  2. Remove the release files in dev directory
  3. Remove the the release file for the previous release under official release directory, which will be archived and can be found here
  4. Publish release notes on Github.
  5. Update the recommend dependency on Github to the latest version, also update the version in other place if necessary.
  6. Add the download link to official website, using the ASF mirror system. The latest release download link should be something like$VERSION/apache-dubbo-$ The download link for the previous release version should be changed like$VERSION/apache-dubbo-$ Please refer to the download page for more details.
  7. Make sure all the commits in the release branch are merged into master branch, and then remove the remote release branch. For example: git push origin --delete 2.7.0-release
  8. Send mail to and, notify the community that the release is completed. The mail template to announce release:
Hello Community,

The Apache Dubbo team is pleased to announce that the
2.6.6 has just been released.

Apache Dubbo™  is a high-performance, java based, open source
RPC framework. Dubbo offers three key functionalities, which include
interface based remote call, fault tolerance & load balancing, and
automatic service registration & discovery.

Both the source release[1] and the maven binary release[2] are available
now, you can also find the detailed release notes in here[3].

If you have any usage questions, or have problems when upgrading or find
any problems about enhancements included in this release, please don’t
hesitate to let us know by sending feedback to this mailing list or filing
an issue on GitHub[4].


Apache Dubbo is an effort undergoing incubation at The Apache Software Foundation (ASF), sponsored by the Incubator. Incubation is required of all newly accepted projects until a further review indicates that the infrastructure, communications, and decision making process have stabilized in a manner consistent with other successful ASF projects. While incubation status is not necessarily a reflection of the completeness or stability of the code, it does indicate that the project has yet to be fully endorsed by the ASF.


Complete Maven Convenient Binary release The permissions of the nexus repository have been applied, see jira

To release the maven artifacts, go to, and choose the staging repository, click the release button. Wait for a moment and verify it at here, make sure your artifacts are there and correct. It will take some time to sync to maven central repository. You can verify it at here


gpg: signing failed: Inappropriate ioctl for device

If you’ve encoutered this error, try the following commands:

export GPG_TTY=$(tty)