Evergreen env setting magic

gistfile1.apacheconf

# PerlAddVar is only evaluated at apache startup time
# So you cannot dynamically build things like OILSWebTemplatePath in the apache config
# You could build it in a block of Perl, but that's not great when you have the rest of the config in Apache already
#
# Step 1.
# Add this to EGWeb.pm:
# Immediately below where it's being set already, before it's reversed and stored.
# @template_paths = split(/:/, $ENV{'OILSWebTemplatePath'}) if defined($ENV{'OILSWebTemplatePath'});
# In future, it might be handle to have similar functionality for other settings.
#
# Step 2. Apache 2.4 config
# Will NOT work on older versions of apache

Define eg_localstatedir /srv/openils/var
Define eg_sysconfdir /srv/openils/etc
Define eg_bindir /srv/openils/bin

<VirtualHost *:80>
ServerName catalogue.libraries.coop
ServerAlias *.catalogue.libraries.coop

# Base detection stuff
# You should probably tweak this, it's a simplified version for this Gist
SetEnvIfNoCase Host ^(?:(?:app|dev|testing|training|migration)[0-9]+\.)?catalogue\.libraries\.coop$ shortname=default
SetEnvIfNoCase Host ^(.+)(?:\.(?:app|dev|testing|training|migration)[0-9]+)\.catalogue\.libraries\.coop$ shortname=$1

# Extra detection, built from data
# You should probably tweak this, it's a simplified version for this Gist
SetEnvIfNoCase Host ^whistler.bc(?:\.(?:app|dev|testing|training|migration)[0-9]+)?\.catalogue\.libraries\.coop$
# ...

# Fallback
SetEnvIfNoCase shortname ^$ shortname=default

# The following blocks are built from data
SetEnvIfNoCase shortname ^default$ \
        physical_loc=1 \
        prov=bc \
        orgid=1 \
        skin=default \
        shortname=default \
        !locg \
        bibliocommons=0 \ 
        !bibc_hostname

SetEnvIfNoCase shortname ^ABLB$ \
        physical_loc=1101 \
        prov=mb \
        orgid=1101 \
        skin=ABLB \
        shortname=ABLB \
        !locg \
        bibliocommons=0 \
        !bibc_hostname

SetEnvIfNoCase shortname ^BW$ \
        physical_loc=10 \
        prov=bc \
        orgid=10 \
        skin=BW \
        shortname=BW \
        !locg \
        bibliocommons=1 \
        bibc_hostname=whistler \
        OILS_NOVELIST_URL=https://... \
        OILS_NOVELIST_PROFILE=... \
        OILS_NOVELIST_PASSWORD=... 


# ...
# End of built blocks

# This is the fallback case
SetEnvIf shortname ^default$ \
        physical_loc=1 \
        prov=bc \
        orgid=1 \
        skin=default \
        shortname=default \
        !locg \
        bibliocommons=0 \
        !bibc_hostname

# Include rewrites, that use the variables above
Include .../499.rewrites.conf-include
# Now include the vhost config, modified slightly to take variables
Include .../eg_vhost.conf-include

<Location /eg>
  # We validate the the skin is actually a directory that exists before using it
  # There is no trivial way to merge two settings, so sadly we have to write it out in full here.
  <If "-n '%{reqenv:skin}' && -d '${eg_localstatedir}/skins/%{reqenv:skin}'">
    SetEnvIfNoCase skin ^(.*)$  \
      OILSWebTemplatePath=${eg_localstatedir}/templates:${eg_localstatedir}/templates_SITKA:${eg_localstatedir}/skins/$1
  </If>
  <Else>
    SetEnvIfNoCase skin ^(.*)$ \
      OILSWebTemplatePath=${eg_localstatedir}/templates:${eg_localstatedir}/templates_SITKA
  </Else>
</Location>