ci: Switch to K8s build agent

ci/Jenkinsfile

@@ -2,16 +2,12 @@
 
 pipeline {
     agent {
-        dockerfile {
-            dir 'ci'
-            args '''
-            -v /etc/ssh/ssh_known_hosts:/etc/ssh/ssh_known_hosts
-            --pids-limit 16384
-            '''
-            additionalBuildArgs '''\
-            --build-arg UID=$(id -u) \
-            --build-arg GID=$(id -g) \
-            '''
+        kubernetes {
+            yamlFile 'ci/podTemplate.yaml'
+            defaultContainer 'buildroot'
+            workspaceVolume persistentVolumeClaimWorkspaceVolume(
+                claimName: 'jenkins-ws-metricspi'
+            )
         }
     }
 
@@ -20,10 +16,6 @@ pipeline {
         disableConcurrentBuilds()
     }
 
-    triggers {
-        pollSCM ''
-    }
-
     parameters {
         booleanParam \
             name: 'Clean',
@@ -32,6 +24,9 @@ pipeline {
 
     environment {
         BUILDROOT_SRC = "${env.WORKSPACE}/buildroot"
+        TMPDIR = "${env.WORKSPACE_TMP}"
+        TEMP = "${env.WORKSPACE_TMP}"
+        TMP = "${env.WORKSPACE_TMP}"
     }
 
     stages {