diff --git a/provision-contest/ansible/Makefile b/provision-contest/ansible/Makefile
index 06f39de7..13f347cf 100644
--- a/provision-contest/ansible/Makefile
+++ b/provision-contest/ansible/Makefile
@@ -29,33 +29,33 @@ VENDOR=
 else
 VENDOR=roles/domjudge_checkout/files/webapp/vendor
 $(VENDOR): $(VENDORTGZ)
-	-cd roles/domjudge_checkout/files/webapp && tar xzf ../$(notdir $<)
+	-mkdir -p roles/domjudge_checkout/files/webapp && cd roles/domjudge_checkout/files/webapp && tar xzf ../$(notdir $<)
 endif
 
 ROLES=domserver judgehost admin grafana cds presclient presadmin scoreboard mgmt autoanalyst
 $(ROLES): %: %.yml hosts group_vars/all/secret.yml $(VENDOR) $(SSHKEY) $(SSHKEY).pub
-	ansible-playbook -i hosts $<
+	ansible-playbook $<
 
 FAILED_ROLES=$(addprefix failed-,$(ROLES))
 $(FAILED_ROLES): failed-%: %.yml %.retry
-	ansible-playbook -i hosts --limit @$*.retry $<
+	ansible-playbook --limit @$*.retry $<
 
 CODEONLY_ROLES=$(addprefix codeonly-,domserver judgehost admin)
 $(CODEONLY_ROLES): codeonly-%:
-	ansible-playbook -i hosts --tags pretask,domjudge_build $*.yml
+	ansible-playbook --tags pretask,domjudge_build $*.yml
 
 powerloss:
-	ansible-playbook -i hosts emergency.yml --tags powerloss
+	ansible-playbook emergency.yml --tags powerloss
 
 lockdown:
-	ansible-playbook -i hosts emergency.yml --tags full_lockdown
+	ansible-playbook emergency.yml --tags full_lockdown
 
 lockdown-force:
-	ansible-playbook -i hosts emergency.yml --tags full_lockdown,force_lockdown
+	ansible-playbook emergency.yml --tags full_lockdown,force_lockdown
 
 ansible-master:
 	for book in $(ROLES) ; do \
-		ansible-playbook -i hosts $$book.yml --tags install_master ; \
+		ansible-playbook $$book.yml --tags install_master ; \
 	done
 
 admin: $(SSL_LOCALHOST_FILES)
diff --git a/provision-contest/ansible/admin.yml b/provision-contest/ansible/admin.yml
index e847f41d..410bc2a4 100644
--- a/provision-contest/ansible/admin.yml
+++ b/provision-contest/ansible/admin.yml
@@ -52,6 +52,7 @@
         state: present
         pkg:
           - ansible
+          - ansible-lint
           - git-gui
           - gitk
           - makepasswd
diff --git a/provision-contest/ansible/ansible.cfg b/provision-contest/ansible/ansible.cfg
index ee6bd190..66a618f3 100644
--- a/provision-contest/ansible/ansible.cfg
+++ b/provision-contest/ansible/ansible.cfg
@@ -5,6 +5,7 @@ system_warnings = True
 strategy = free
 retry_files_enabled = True
 retry_files_save_path = ~/.ansible-retry
+inventory = hosts
 
 [connection]
 ssh_args = -C -o ControlMaster=auto -o ControlPersist=60s
diff --git a/provision-contest/ansible/roles/domjudge_checkout/files/.gitignore b/provision-contest/ansible/roles/domjudge_checkout/files/.gitignore
index 13ecffc5..1a2afa60 100644
--- a/provision-contest/ansible/roles/domjudge_checkout/files/.gitignore
+++ b/provision-contest/ansible/roles/domjudge_checkout/files/.gitignore
@@ -1,3 +1,4 @@
 /lib
 /lib-vendor.tgz
 /vendor.tgz
+/webapp
diff --git a/provision-contest/ansible/roles/grafana/templates/prometheus.yml.j2 b/provision-contest/ansible/roles/grafana/templates/prometheus.yml.j2
index 8352c07c..0a92791a 100644
--- a/provision-contest/ansible/roles/grafana/templates/prometheus.yml.j2
+++ b/provision-contest/ansible/roles/grafana/templates/prometheus.yml.j2
@@ -24,8 +24,8 @@ scrape_configs:
         - {{ hostvars[host].ansible_host }}:9100
 {% endfor %}
 {% endif %}
-{% if groups["domserver"][0] is defined %}
-  - job_name: {{ group_prefix ~ domjudge }}
+{% if groups[group_prefix+"domserver"][0] is defined %}
+  - job_name: {{ group_prefix ~ 'domjudge' }}
     basic_auth:
       username: admin
       password: {{ ADMIN_PASSWORD }}