ten7/flight-deck-varnish repository overview

⁠Flight Deck Varnish

Flight Deck Varnish is a minimalist Varnish container for Drupal sites on Kubernetes and Docker. You can use it both for local development and production.

Features:

• ConfigMap-friendly YAML configuration

⁠Tags and versions

There are several tags available for this container, each with different Solr and module support:

⁠Configuration

This container does not use environment variables for configuration. Instead, the flight-deck-varnish.yml file is used to handle all configuration.

---
flightdeck_varnish:
  secret: "secretish"
  hostPort: "6081"
  controlPort: "6082"
  memSize: "256m"
  storageFile: "/var/lib/varnish/storage.bin"
  storageSize: "1024m"

Where:

• secret is the Varnish secret used to access the control terminal. Optional.
• hostPort is the port on which the Varnish proxy is available. Optional, defaults to 6081.
• controlPort is the port for the Varnish control terminal. Optional, defaults to 6082.
• memSize is the size of memory to dedicate to caching. Optional, defaults to 256m.
• storageFile is the full path in the container to the file to use for longer term varnish caching. Optional, defaults to /var/lib/varnish/storage.bin.
• storageSize is the size of the storage file. Optional, defaults to 1024m.

⁠Describing backends

Varnish acts as a caching reverse HTTP proxy. You can specify one or more backends by defining the flightdeck_varnish.backends list:

---
flightdeck_varnish:
  backends:
   - name: "default"
     host: "web"
     port: "80"

For each item:

• name is the a name of the backend. Required.
• host is the IP address, hostname, or fully qualified DNS name with which to access the backend. Required.
• port is the port with which to access the backend. Optional, defaults to 80.

⁠Using separate files for credentials

Sometimes, you may wish to keep certain credentials in separate files from the rest of the configuration. One such case is if you want to keep flight-deck-varnish.yml in a Kubernetes configmap, but keep the database passwords in secrets instead.

---
flightdeck_varnish:
  secretFile: "/config/varnish-secret/secret.txt"

Where:

• secretFile is the path in the container to the file containing the varnish secret.

⁠Controlling backend timeouts

Depending on your application, you may need to specify a particular series of timeouts in order for Varnish to consider your backend "healthy". You can specify these per backend:

---
flightdeck_varnish:
  backends:
    - name: "default"
      host: "web"
      port: "80"
      firstByteTimeout: "300s"
      connectTimeout: "5s"
      betweenBytesTimeout: "2s"

Where:

• firstByteTimeout is the amount of time to wait for the bakend to return the first byte. Optional, default is 300 seconds.
• connectTimeout is the amount of time to wait when establishing a connection to the backend. Optional, default is 5 seconds.
• betweenBytesTimeout is the time to wait between each byte. Optional, default is 2 seconds.

⁠Probing health

Varnish can routinuely check the health of the backend through a "probe".

---
flightdeck_varnish:
  backends:
    - name: "default"
      host: "web"
      port: "80"
      probe: no
      probeHost: "www.example.com"
      probeHeaders:
        - name: "X-Forwarded-Proto"
          value: "https"
      probeInterval: "15s"
      probeTimeout: "5s"
      probeThreshold: 3
      probeWindow: 5

Where:

• probe is enables (yes) or disables (no) probe behavior. Optional, default is no.
• probeHost is the hostname to pass to the backend when doing the probe. Some content managers like Drupal expect a particular hostname and will fail without it. Optional, defaults to localhost.
• probeHeaders is a list of name/value pairs of HTTP headers to pass to the backend during the probe. This is useful for passing the X-Forwarded-Proto if you are terminating HTTPS at your load balancer. Optional, defaults to no additional headers.
• probeInterval is the time in seconds to conduct the probe. Optional, default is 15 seconds.
• probeTimeout is the time to wait for a response when probing. Optional, defaults to 5 seconds.
• probeThreshold is the amount of probes which must succeed within the last number of probe attempts specified by probeWindow. Optional, defaults to 3.
• probeWindow is the number of probe attempts to consider when checking the probe. Optional, defaults to 5.

⁠Excluding paths from caching

Some paths, such administration paths, key user interaction paths should not be cached by varnish. If the user login page is cached, for example, you may not be able to login, as Varnish would return the un-logged in HTML each time.

You can configure which items always bypass the cache in the configuration file:

---
flightdeck_varnish:
  skipCache:
    - "^/status\\.php$"
    - "^/update\\.php"
    - "^/install\\.php"
    - "^/wp-login\\.php$"
    - "^/apc\\.php$"
    - "^/admin"
    - "^/admin/.*$"
    - "^/user"
    - "^/user/.*$"
    - "^/users/.*$"
    - "^/info/.*$"
    - "^/flag/.*$"
    - "^/wp-admin/.*$"
    - "^.*/ahah/.*$"
    - "^/system/files/.*$"

Where:

• skipCache is a list of regular expressions which match URL paths to skip caching. Note, YAML needs backslashes to be escaped with another backslash. Optional, the container will skip best practice Drupal and Wordpress paths.

⁠Excluding cookies from caching

Often, you may wish to skip caching based on the presence of key cookies. You can configure which ones using keepCookies:

---
flightdeck_varnish:
  keepCookies:
    - "SESS[a-z0-9]+"
    - "SSESS[a-z0-9]+"
    - "NO_CACHE"
    - "XDEBUG_SESSION"
    - "wordpress_logged_in_[a-z0-9]+"
    - "wordpress_sec_[a-z0-9]+"
    - "wp-settings-[0-9]+"
    - "wp-settings-time-[0-9]+"

Where:

• keepCookies is a list of regular expressions which match cookie names (not values). Optional, the container will skip best practice Drupal and Wordpress paths.

⁠Controlling cache times

By default, any responses from the backend will be cached in accordance with the max-age header. There are two additional parmeters which allows you to control caching:

---
flightdeck_varnish:
  grace: "6h"
  staticTtl: "15m"

Where:

• grace is the time in hours to retain cached content in "grace", that is, beyond the value of the max-age header when set.
• staticTtl is the amount of time to cache static content according to file extension.

⁠Customizing the error page

Often, you may wish to skip caching based on the presence of key cookies. You can configure which ones using keepCookies:

---
flightdeck_varnish:
  errorPage: |
    <html>
    <body>
    Something is broken!
    </body>
    </html>

Where:

• errorPage is the HTML to display due to a varnish error.

⁠Deployment on Kubernetes

Use the ten7.flightdeck_cluster⁠ role on Ansible Galaxy to deploy DB as a statefulset:

flightdeck_cluster:
  namespace: "example-com"
  configMaps:
    - name: "flight-deck-varnish"
      files:
        - name: "flight-deck-varnish.yml"
          content: |
          flightdeck_varnish:
            secret: "secretish"
            hostPort: "6081"
            controlPort: "6082"
            memSize: "256m"
            storageFile: "/var/lib/varnish/storage.bin"
            storageSize: "1024m"
            backends:
             - name: "default"
               host: "web"
               port: "80"
  web:
    replicas: 1
    configMaps:
      - name: "flight-deck-varnish"
        path: "/config/varnish"

⁠Using with Docker Compose

Create the flight-deck-varnish.yml file relative to your docker-compose.yml. Define the varnish service mounting the file as a volume:

version: '3'
services:
  varnish:
    image: ten7/flight-deck-varnish:6
    ports:
      - 6081:6081
      - 6082:6082
    volumes:
      - ./flight-deck-varnish.yml:/config/varnish/flight-deck-varnish.yml

⁠Part of Flight Deck

This container is part of the Flight Deck library⁠ of containers for Drupal local development and production workloads on Docker, Swarm, and Kubernetes.

Flight Deck is used and supported by TEN7⁠.

⁠Debugging

If you need to get verbose output from the entrypoint, set flightdeck_debug to true or yes in the config file.

---
flightdeck_debug: yes

This container uses Ansible⁠ to perform start-up tasks. To get even more verbose output from the start up scripts, set the ANSIBLE_VERBOSITY environment variable to 4.

If the container will not start due to a failure of the entrypoint, set the FLIGHTDECK_SKIP_ENTRYPOINT environment variable to true or 1, then restart the container.

⁠License

Flight Deck is licensed under GPLv3. See LICENSE⁠ for the complete language.