snapcraft: Add support for extra version information

- frr.version snap command will now show the contents of
  extra_version_info.txt in addition to the zebra --version output

Signed-off-by: Martin Winter <mwinter@opensourcerouting.org>

snapcraft/Makefile.am

@@ -1,6 +1,7 @@
 EXTRA_DIST = snapcraft.yaml \
 	README.snap_build.md \
 	README.usage.md \
+	extra_version_info.txt \
 	scripts \
 	defaults \
 	helpers \

snapcraft/README.snap_build.md

@@ -12,7 +12,12 @@ which uses earlier versions of snaps)
         git clone https://github.com/frrouting/frr.git
         cd frr
 
-3. Run Bootstrap and make distribution tar.gz
+3. (Optional) Add extra version information to 
+   `snapcraft/extra_version_info.txt`. Information in this file will
+   be displayed with the frr.version command (simple `cat` after
+   the display of the `zebra --version` output)
+
+4. Run Bootstrap and make distribution tar.gz
 
         ./bootstrap.sh
         ./configure --with-pkg-extra-version=-MySnapVersion
@@ -25,7 +30,7 @@ which uses earlier versions of snaps)
     This will build `frr-something.tar.gz` - the distribution tar and 
     the snapcraft/snapcraft.yaml with the matching version number
 
-4. Create snap
+5. Create snap
 
         cd snapcraft
         snapcraft

snapcraft/scripts/Makefile

@@ -13,3 +13,5 @@ install:
 	install -D -m 0755 ldpd-service $(DESTDIR)/bin/
 	install -D -m 0755 nhrpd-service $(DESTDIR)/bin/
 	install -D -m 0755 set-options $(DESTDIR)/bin/
+	install -D -m 0755 show_version $(DESTDIR)/bin/
+

snapcraft/scripts/show_version

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+$SNAP/sbin/zebra --version
+$SNAP/bin/cat $SNAP/doc/extra_version_info.txt
+
+exit 0

snapcraft/snapcraft.yaml.in

@@ -17,7 +17,7 @@ apps:
             - network-bind
             - network-control
     version:
-        command: sbin/zebra --version
+        command: bin/show_version
     readme:
         command: bin/cat $SNAP/doc/README.usage.md
     zebra:
@@ -254,4 +254,5 @@ parts:
         organize:
             README.usage.md: doc/README.usage.md
             README.snap_build.md: doc/README.snap_build.md
+            extra_version_info.txt: doc/extra_version_info.txt