woodpecker: refactor pipeline

.woodpecker/dns.yml

@@ -1,6 +1,6 @@
 pipeline:
   validate:
-    image: alpine
+    image: alpine:3.16
     when:
       path: "dns/**"
       event: pull_request
@@ -9,25 +9,24 @@ pipeline:
     commands:
       - apk add --no-cache terraform
       - terraform version
-      - |
-        cd dns
-        echo 'token = "$${LINODE_TOKEN}"' > .auto.tfvars
-        terraform validate
-        terraform plan
+      - cd dns
+      - terraform init
+      - terraform validate
+      - terraform plan -var "token=$LINODE_TOKEN"
 
   deploy:
-    image: alpine
+    image: alpine:3.16
     when:
       path: "dns/**"
+      branch: main
       event: push
     secrets:
       - linode_token
     commands:
       - apk add --no-cache terraform
       - terraform version
-      - |
-        cd dns
-        echo 'token = "$${LINODE_TOKEN}"' > .auto.tfvars
-        terraform validate
-        terraform plan -out deploy.plan
-        terraform apply deploy.plan
+      - cd dns
+      - terraform init
+      - terraform validate
+      - terraform plan -out deploy.plan -var "token=$LINODE_TOKEN"
+      - terraform apply deploy.plan -var "token=$LINODE_TOKEN"