A web server

In this page, you install nginx, turn on a firewall, and write a home page.

Add these steps to winch.yaml:

name: example

hosts:
  web1.example.com:
    user: admin

steps:
  - name: Install nginx and nftables
    pkg:
      name: [nginx, nftables]

  - name: Allow SSH and HTTP; drop the rest
    firewall:
      allow:
        - tcp: [22, 80]

  - name: Write the home page
    file:
      path: /var/www/html/index.html
      content: |
        <!doctype html>
        <title>example.com</title>
        <p>Hello from winch.</p>

  - name: Run nginx
    service:
      name: nginx
      running: true
      enabled: true

The steps run in order:

1. pkg installs nginx, and nftables for the firewall.
2. firewall allows SSH and HTTP, and drops all other incoming traffic.
3. file writes the home page into the web root of nginx.
4. service starts nginx, and starts it again at each boot.

name describes the step in the output. The modules reference lists the arguments of each module.

Plan

To see what winch will change, run winch plan:

winch plan

web1.example.com
  example
    + Install nginx and nftables: pkg nginx, nftables
        refresh the package index
        install nginx, nftables
        other packages: known after the refresh
    + Allow SSH and HTTP; drop the rest: firewall
        add tcp 22, 80
        create directory /etc/winch (owner root, group root, mode 0755)
        create file /etc/winch/firewall.nft (owner root, group root, mode 0644)
        create file /etc/systemd/system/winch-firewall.service (owner root, group root, mode 0644)
        create directory /etc/systemd/system/nftables.service.d (owner root, group root, mode 0755)
        create file /etc/systemd/system/nftables.service.d/winch.conf (owner root, group root, mode 0644)
        daemon-reload
        enable winch-firewall.service
        load the rules
    + Write the home page: file /var/www/html/index.html
        create directory /var/www (owner root, group root, mode 0755)
        create directory /var/www/html (owner root, group root, mode 0755)
        owner root, group root, mode 0644
        @@ -0,0 +1,3 @@
        +<!doctype html>
        +<title>example.com</title>
        +<p>Hello from winch.</p>
    ~ Run nginx: service nginx
        nginx.service does not exist yet
        enable
        start

1 host: 1 to change, 0 unchanged, 0 unknown
plan 16580ad9c636c795

The plan lists each step that will change something on the server. + marks something new, and ~ marks a change. Under each step, you see what exactly will happen. The plan changes nothing on the server.

Apply

To make the changes, run winch apply. It shows the same plan and asks. Type y:

winch apply

Apply these changes? [y/N] y
web1.example.com: example: + Install nginx and nftables: pkg nginx, nftables
web1.example.com: example: + Allow SSH and HTTP; drop the rest: firewall
web1.example.com: example: + Write the home page: file /var/www/html/index.html

1 host: 1 changed, 0 unchanged

Run nginx has no line: the install of the package already started nginx.

Check the page from the server:

winch exec web1.example.com -- curl -s http://localhost/

web1.example.com
  <!doctype html>
  <title>example.com</title>
  <p>Hello from winch.</p>

Run winch plan again:

1 host: 0 to change, 1 unchanged, 0 unknown
plan a45062412bba9ac8

The server matches the project, so there is nothing to change.

Change the page

Change the text of the page in winch.yaml:

      content: |
        <!doctype html>
        <title>example.com</title>
        <p>Welcome to example.com.</p>

winch plan shows the change as a diff:

web1.example.com
  example
    ~ Write the home page: file /var/www/html/index.html
        @@ -1,3 +1,3 @@
         <!doctype html>
         <title>example.com</title>
        -<p>Hello from winch.</p>
        +<p>Welcome to example.com.</p>

1 host: 1 to change, 0 unchanged, 0 unknown
plan c0c0648e5fb0e750

Apply it with winch apply.

Next: Environments.