Update Jenkinsfile's to use Ubuntu-based images

Update Jenkinsfile's to use Ubuntu-based images to deploy airskiff and
seaworthy sites.

Change-Id: I1b33493081f8618d91c66088e943f6033d71e3c5

doc/source/airsloop.rst

@@ -33,6 +33,8 @@ are setup to deploy OpenStack Ocata.
 The versions are kept up to date via `updater.py <https://opendev.org/airship/treasuremap/src/branch/master/tools/updater.py>`__,
 a utility that updates versions.yaml latest charts and (selected) images.
 
+Due to the limited capacity of a test environment, only Ubuntu-based images are used at the moment.
+
 The pipeline attempts to uplift and deploy latest versions on daily basis.
 
 

doc/source/seaworthy.rst

@@ -26,6 +26,8 @@ are setup to deploy OpenStack Ocata.
 The versions are kept up to date via `updater.py <https://opendev.org/airship/treasuremap/src/branch/master/tools/updater.py>`__,
 a utility that updates versions.yaml latest charts and (selected) images.
 
+Due to the limited capacity of a test environment, only Ubuntu-based images are used at the moment.
+
 The pipeline attempts to uplift and deploy latest versions on daily bases.
 
 

tools/gate/Jenkinsfile

@@ -232,7 +232,7 @@ def uplift_versions = {
     stage('Uplift Versions') {
         sh 'sudo apt-get install python3-yaml python3-git -y'
 
-        def cmd = 'tools/updater.py --in-file global/software/config/versions.yaml'
+        def cmd = 'tools/updater.py --in-file global/software/config/versions.yaml --tag-filter ubuntu'
 
         if (!UPLIFT_BLACKLIST.isEmpty()) {
            cmd += " --skip ${UPLIFT_BLACKLIST}"

tools/gate/airsloop/Jenkinsfile

@@ -232,7 +232,7 @@ def uplift_versions = {
     stage('Uplift Versions') {
         sh 'sudo apt-get install python3-yaml python3-git -y'
 
-        def cmd = 'tools/updater.py --in-file global/software/config/versions.yaml'
+        def cmd = 'tools/updater.py --in-file global/software/config/versions.yaml --tag-filter ubuntu'
 
         if (!UPLIFT_BLACKLIST.isEmpty()) {
            cmd += " --skip ${UPLIFT_BLACKLIST}"