Updating IGTF version:

- Find and download the latest igtf-policy-installation-bundle-<IGTF_VER>.tar.gz
  from https://dist.eugridpma.info/distribution/igtf/current/

- copy this igtf bundle tarball to the upstream area:
  igtf-policy-installation-bundle/<IGTF_VER>/igtf-policy-installation-bundle-<IGTF_VER>.tar.gz

- update {igtf,osg}-ca-certs/upstream/igtf.upstream.source in packaging with
  this new tarball + checksum

- inside new igtf bundle, get changes from CHANGES for the latest igtf release,
  add these changes to CHANGES here, in osg-certificates

- bump the igtf_version and osg_version in rpm/{igtf,osg}-ca-certs.spec,
  add changelog entries

- commit osg-certificates changes and tag v<OSG_VER>.igtf.<IGTF_VER>;
  push changes to opensciencegrid/osg-certificates (push master and new tag)
  
- update {igtf,osg}-ca-certs/upstream/osg-certificates.github.source in
  packaging; bump all occurances of OSG_VER and IGTF_VER, and update 'hash'
  to match the new tagged commit.

  NOTE: the 'name' parameter in osg-certificates.github.source matches the
  package name, {igtf,osg}-ca-certs, respectively.


Making OSG changes:

All OSG-specific stuff is done in "build-certificates-dir.sh" in the block
with the comment "OSG Specific stuff".

Currently the only thing here is to add letsencrypt certs, but in theory
other certs could be added or removed from here.


Updating the letsencrypt tarball:

It is not necessary to update the letsencrypt tarball every time, but if
we want to update it we can as follows.

As is documented in rpm/osg-ca-certs.spec, you can *obtain* the latest
letsencrypt-certificates.tar.gz with a github.source line:

  type=github repo=cilogon/letsencrypt-certificates tarball=letsencrypt-certificates.tar.gz tag=master hash=...

You can use the 'fetch-dot-source' util from osg-build to download this tarball.

  $ cd /tmp
  $ echo type=github repo=cilogon/letsencrypt-certificates tarball=letsencrypt-certificates.tar.gz tag=master hash=... > letsencrypt.github.source
  $ fetch-dot-source letsencrypt.github.source

You may have to update the 'hash' parameter to match the current upstream
master commit, or else run fetch-dot-source with the '-n' option to ignore
a hash mismatch.

Since this is an externally controlled repo, we want to keep this source in our
upstream source cache.  So, after downloading a new letsencrypt tarball, copy
it to our upstream source cache, and update the
osg-ca-certs/upstream/letsencrypt.tarball.source appropriately:

  letsencrypt-certificates/git_36f6703/letsencrypt-certificates.tar.gz sha1sum=9c936fb6b6141c038b0ef58e7982cf482dfe9026