Source Release for libdap

From OPeNDAP Documentation

This page covers the step needed to release the libdap software for Hyrax. There is are separate pages for the BES and OLFS code and an overview page that describes how the website is updated and lists are notified.

We now depend on the CI/CD process to build binary packages and to test the source builds. When the source code is tagged and marked as a release in GitHub, our linked Zenodo account archives that software and mints a DOI for it.

The Release Process

Tip: If, while working on the release, you find you need to make changes to the code and you know the CI build will fail, do so on a release branch that you can merge and discard later. Do not make a release branch unless you need to since it complicates making tags.

Verify the code base

  1. We release using the master branch. The code on master must pass the CI build.
  2. Make sure that the source code you're using for the following steps is up-to-date. (git pull)

Update Release Files

Update the text documentation files and version numbers in the configuration files:

Update the ChangeLog file.

Use the script gitlog-to-changelog (which can be found with Google) to update the ChangeLog file by running it using the --since="<date>" option with a date one day later in time than the newest entry in the current ChangeLog.

gitlog-to-changelog --since="1970-01-01" (Specify a date one day later than the one at the top of ChangeLog)

Save the result to a temp file and combine the two files:

cat tmp ChangeLog > ChangeLog.tmp; mv ChangeLog.tmp ChangeLog

If you're making the first ChangeLog entries, then you'll need to create the ChangeLog file first.
Tip: When you're making the commit log entries, use line breaks so ChangeLog will be readable. That is, use lines < 80 characters long.

Update the NEWS file

To update the NEWS file, just read over the new ChangeLog entries and summarize.

Update the Version Numbers for Humans

  1. Determine the human version number. This appears to be a somewhat subjective process.
  2. Edit each of the Affected Files and update the human version number.
  3. Update the internal library version numbers
There are really 2 version numbers for each of these project items. The human version (like version-3.17.5) and the library API/ABI version which is represented as CURRENT:REVISION:AGE. There are special rules for when each of the numbers in the library API/ABI version get incremented that are triggered by the kinds of changes that where made to the code base. The human version number is more arbitrary. So for example, we might make a major API/ABI change and have to change to a new Libtool version like 25:0:0 but the human version might only change from bes-3.17.3 to bes-3.18.0
The rules for shared image version numbers:
  1. No interfaces changed, only implementations (good): Increment REVISION.
  2. Interfaces added, none removed (good): Increment CURRENT, increment AGE, set REVISION to 0.
  3. Interfaces removed or changed (BAD, breaks upward compatibility): Increment CURRENT, set AGE and REVISION to 0.
See How to see the scope of API/ABI changes in C++ sources below for gruesome details. Often basic knowledge of the edits is good enough.
Affected Files
debian/changelog (see Debian ChangeLog)
Take Note! The debian/changelog is the "single source of truth" for the libdap4 version in the debian packaging. If this does not agree with the version being packaged the package build will fail.
README,, ...

It's helpful to have, in the NEWS file, the Web site and the release notes, a list of the Jira tickets that have been closed since the last release. The best way to do this is to goto Jira's Issues page and look at the Tickets closed recently item. From there, click on Advanced and edit the time range so it matches the time range since the past release to now, then Export that info as an excel spreadsheet (the icon with a hat and a down arrow). YMMV regarding how easy this is and Jira's UI changes often.


  • Commit and push the ocde. Wait for the CI/CD builds to complete. You must be working on the master branch to get the CD package builds to work.


  • This will trigger a 'archive and DOI' process on the Zenodo system.

Tag The Release

  1. git tag -m "version-<number>" -a <numbers> (this was git tag -m "version-<number>" -a version-<numbers> but we have had a request to switch to plan version numbers to be more conformant with common practice WRT git version tags).
  2. git push origin <numbers>

If this is part of Hyrax, also tag this point in the master branch with the Hyrax release number:

  1. git tag -m "hyrax-<number>" -a hyrax-<numbers> I think we can leave this tag as hyrax-<version> since it's for our own bookkeeping.
  2. git push origin hyrax-<numbers>
    NB: Instead of tagging the HDF4/5 modules, use the saved commit hashes that git tracks for submodules. This cuts down on the bookkeeping for releases and removes one source of error.
  3. Mark the release on Github:
    • Goto the 'releases' page and click the 'Tags' tab. There, click the ellipses (...) on the right of the 'version-*' tag and:
      • Enter a title for the release
      • Copy the most recent text from the NEWS file into the describe field
      • Click Update this release or Save draft

Publish and Sign

When the release is made on GitHub the source tar bundle is made automatically. However, this bundle is not the one we wish to publish because it requires people to have autoconf installed. Rather we want to use the result of "make dist" which will have the configure script pre-generated.

All you need do is build the tar file using make dist, sign it, and push (or pull) these files onto

  1. Go to the libdap4 project on your local machine and run make dist which will make a libdap-x.y.z.tar.gz file at the top level of the libdap4 project.
  2. Use gpg to sign the tar bundle:
    gpg --detach-sign --local-user libdap-x.y.z.tar.gz
  3. Use sftp to push the signature file and the tar bundle to the /httpdocs/pub/source directory on
    (Assuming your current working directory is the top of the bes project)
    cd httpdocs/pub/source
    put libdap-x.y.z.tgz.sig
    put libdap-x.y.z.tgz
  4. Check your work!
    1. Download the source tar bundle and signature from
    2. Verify the signature:
      gpg --verify libdap-x.y.z.tgz.sig libdap-x.y.z.tgz

Get the DOI from Zenodo

  1. Goto Zenodo and look at the 'upload' page. Since the libdap, BES and OLFS repositories are linked to Zenodo, the newly-tagged code is uploaded to Zenodo automatically and a DOI is minted for us.
  2. Click on the new version, then click on the DOI tag in the pane on the right of the page for the given release.
  3. Copy the DOI as markdown from the window that pops up and paste that into the info for the version back in Github land.
  4. Also paste that into the README file. Commit using [skip ci] so we don't do a huge build (or do the build, it really doesn't matter that much).

Images for the above steps to help with the web UI: coming soon

How to see the scope of API/ABI changes in C++ sources

Determine the new software version (assuming you don't already know the extent of the changes that have been made)

For C++, build a file of the methods and their arguments using:
nm .libs/libdap.a | c++filt | grep ' T .*::' | sed 's@.* T \(.*\)@\1@' > libdap_funcs
and compare that using diff on the previous release's library.

Assess the changes you find based on the following rules for the values of CURRENT,REVISION, and AGE

  • No interfaces changed, only implementations (good): ==> Increment REVISION.
  • Interfaces added, none removed (good): ==> Increment CURRENT, increment AGE, set REVISION to 0.
  • Interfaces removed or changed (BAD, breaks upward compatibility): ==> Increment CURRENT, set AGE and REVISION to 0.

The current value of CURRENT,REVISION, and AGE can be found in


Once you have determined the new values of the CURRENT:REVISION:AGE strings then:

Edit the and update the version values to the new ones.