ci: Begin Jenkins pipeline

This target can be used in CI to update an existing `.config` file.

Makefile

@@ -14,6 +14,9 @@ $(O)/.config:
 		O=$(O) \
 		$(DEFCONFIG)
 
+.PHONY: update-config
+update-config:
+	$(MAKE) -C $(O) $(DEFCONFIG)
 
 %:
 	$(MAKE) -C $(O) $@

ci/Jenkinsfile

@@ -0,0 +1,68 @@
+pipeline {
+    parameters {
+        booleanParam 'CLEAN_BUILD'
+    }
+
+    options {
+        disableConcurrentBuilds()
+    }
+
+    agent {
+        kubernetes {
+            yamlFile 'ci/podTemplate.yaml'
+            yamlMergeStrategy merge()
+            workspaceVolume persistentVolumeClaimWorkspaceVolume(
+                claimName: 'buildroot-airplaypi'
+            )
+            defaultContainer 'build'
+        }
+    }
+
+    environment {
+        BR2_CCACHE_DIR = "${env.JENKINS_AGENT_WORKDIR}/br2-ccache"
+    }
+
+    stages {
+        stage('Clean') {
+            when {
+                expression {
+                    return params.CLEAN_BUILD
+                }
+            }
+            steps {
+                sh 'git clean -fdx'
+            }
+        }
+
+        stage('Prepare') {
+            steps {
+                container('jnlp') {
+                    sh 'git submodule update --remote aimee-os'
+                }
+            }
+        }
+
+        stage('Build') {
+            steps {
+                sh 'make config && make update-config'
+                sh 'make all'
+            }
+            post {
+                success {
+                    dir('_build') {
+                        archiveArtifacts('.config')
+                    }
+                    dir('_build/images') {
+                        sh 'zstd -f firmware.img'
+                        sh 'zstd -f sdcard.img'
+                        archiveArtifacts([
+                            'firmware.img.zst',
+                            'rootfs.squashfs',
+                            'sdcard.img.zst',
+                        ].join(','))
+                    }
+                }
+            }
+        }
+    }
+}

ci/podTemplate.yaml

@@ -0,0 +1,19 @@
+spec:
+  containers:
+  - name: build
+    image: git.pyrocufflink.net/containerimages/buildroot
+    resources:
+      limits: &resources
+        cpu: 6
+        memory: 12Gi
+      requests: *resources
+    volumeMounts:
+    - mountPath: /etc/ssh/ssh_known_hosts
+      name: ssh-known-hosts
+      subPath: ssh_known_hosts
+  securityContext:
+    fsGroupChangePolicy: OnRootMismatch
+  volumes:
+  - name: ssh-known-hosts
+    configMap:
+      name: ssh-known-hosts