isabella232 / varnish-formula

varnish-formula

A simple SaltStack formula to install and configure Varnish.

This formula has been developed distributing id and state declarations in different files to make it usable in most situations. It should be useful in scenarios ranging from a simple install of the packages (without any special configuration) to a more complex set-up.

Table of Contents

General notes

See the full SaltStack Formulas installation and usage instructions.

If you are interested in writing or contributing to formulas, please pay attention to the Writing Formula Section.

If you want to use this formula, please pay attention to the FORMULA file and/or git tag, which contains the currently released version. This formula is versioned according to Semantic Versioning.

See Formula Versioning Section for more details.

If you need (non-default) configuration, please pay attention to the pillar.example file and/or Special notes section.

Contributing to this repo

Commit message formatting is significant!!

Please see How to contribute for more details.

Special notes

None

General customization strategies

First, see if providing pillar data is enough for your customization needs That's the recommended way and should be enough for most cases. See that sometimes there's a key named extra_conf that's used to add arbitrary configuration lines in the templates provided.

When providing pillar data is not enough for your needs, you can apply the Template Override and Files Switch (TOFS) pattern as described in the documentation file TOFS_pattern.md.

Available states

varnish

Installs the varnish package, and starts the associated varnish service.

varnish.conf

Configures the varnish package.

varnish.repo

Adds the varnish official repositories.

Next-generation, alternate approach

The following states provide an alternate approach to managing Varnish. Tested in Ubuntu 14/16 and CentOS 6/7.

varnish.ng

Meta-state for inclusion of all ng states.

varnish.ng.install

Install varnish itself from custom-repo or stock-repo.

varnish.ng.repo

Install the packagecloud.io varnish repo. Repos available can be found in packagecloud.io

varnish.ng.config

Configure varnish (vcls and init files).

varnish.ng.service

Manage varnish and varnishncsa service.

Varnish NG considerations

Because of the different OSes with different init programs (ubuntu14 - init, ubuntu 16 - systemd, centos 6 - init, centos 7 - systemd), the following considerations must be taken into account:

• VCL files must be copied to minions using salt:// (see pillar.example vcl section):

varnish:
  ng:
    vcl:
      files:
        default:
          path: /etc/varnish/default.vcl
          source_path: salt://hostname/default.vcl.jinja
        mobile_detect:
          enabled: False
          path: /etc/varnish/mobile_detect.vcl
          source_path: salt://hostname/mobile_detect.vcl

• Config files (/etc/default/varnish, /etc/sysconfig/varnish or /etc/varnish/varnish.params) can be copied with salt:// or just creating the variables in the config_file option:

varnish:
  ng:
    config_source_path: salt://hostname/varnish.jinja

or

varnish:
  ng:
    config_file:
      NFILES: "131072"
      MEMLOCK: "82000"
      NPROCS: "unlimited"
      RELOAD_VCL: "1"
      VARNISH_VCL_CONF: "/etc/varnish/default.vcl"
      VARNISH_LISTEN_PORT: "6081"
      VARNISH_ADMIN_LISTEN_ADDRESS: "127.0.0.1"
      VARNISH_ADMIN_LISTEN_PORT: "6082"
      VARNISH_SECRET_FILE: "/etc/varnish/secret"
      VARNISH_MIN_THREADS: "50"
      VARNISH_MAX_THREADS: "1000"
      VARNISH_STORAGE_SIZE: "100M"
      VARNISH_STORAGE: "malloc,${VARNISH_STORAGE_SIZE}"
      VARNISH_TTL: "120"
      DAEMON_OPTS: "-a ${VARNISH_LISTEN_ADDRESS}:${VARNISH_LISTEN_PORT} -f ${VARNISH_VCL_CONF} -T ${VARNISH_ADMIN_LISTEN_ADDRESS}:${VARNISH_ADMIN_LISTEN_PORT} -p thread_pool_min=${VARNISH_MIN_THREADS} -p thread_pool_max=${VARNISH_MAX_THREADS} -S ${VARNISH_SECRET_FILE} -s ${VARNISH_STORAGE}"

• In CentOS 6, it must be explicitely defined the install_from_repo option because in the CentOS 6 repos it is the 2 version:

varnish:
  ng:
    lookup:
      repo: 'varnish41'
    install_from_repo: True

• For the Ubuntu 16 there is a problem regarding the usage of the systemd; there is no other way than editing the systemd varnish unit file to modify the init options (CentOS 7 has also systemd but there is the varnish.params to bypass the edition of the unit file directly). A little trick to automate this, is using the following pillar:

varnish:
  ng:
    lookup:
      repo: 'varnish41'
      config: /etc/systemd/system/varnish.service
    config_source_path: salt://hostname/varnish-systemd

Being varnish-systemd the varnish systemd unit file:

[Unit]
Description=Varnish Cache, a high-performance HTTP accelerator

[Service]
Type=forking

# Maximum number of open files (for ulimit -n)
LimitNOFILE=131072

# Locked shared memory - should suffice to lock the shared memory log
# (varnishd -l argument)
# Default log size is 80MB vsl + 1M vsm + header -> 82MB
# unit is bytes
LimitMEMLOCK=85983232

# On systemd >= 228 enable this to avoid "fork failed" on reload.
#TasksMax=infinity

# Maximum size of the corefile.
LimitCORE=infinity

# Set WARMUP_TIME to force a delay in reload-vcl between vcl.load and vcl.use
# This is useful when backend probe definitions need some time before declaring
# configured backends healthy, to avoid routing traffic to a non-healthy backend.
#WARMUP_TIME=0

ExecStart=/usr/sbin/varnishd -a :6081 -T localhost:6082 -f /etc/varnish/default.vcl -S /etc/varnish/secret -s malloc,120m
ExecReload=/usr/share/varnish/reload-vcl

[Install]
WantedBy=multi-user.target

So you can edit and have the file managed by salt.

• Varnish versions from 6 (including it) have change the systemd unit service; are OS agnostic (see packaging changes).

For Debian Family OSes can use the previous trick (changing the unit service).

For RedHat Family OSes there is a new variable version that setup an override.conf for the default varnish systemd service that allow to use the varnish.params file. For example, to install varnish 6 LTS:

varnish:
  ng:
    lookup:
      repo: 'varnish60lts'
    version: '6'
    install_from_repo: True
    enabled: True
    config_source_path: salt://hostname/varnish.params.jinja
    vcl:
      files:
        default:
          path: /etc/varnish/default.vcl
          source_path: salt://hostname/default.vcl.jinja

This change is compatible with other varnish versions (there is no error if not set).

Testing

Linux testing is done with kitchen-salt.

Requirements

• Ruby
• Docker

$ gem install bundler
$ bundle install
$ bin/kitchen test [platform]

Where [platform] is the platform name defined in kitchen.yml, e.g. debian-9-2019-2-py3.

bin/kitchen converge

Creates the docker instance and runs the template main state, ready for testing.

bin/kitchen verify

Runs the inspec tests on the actual instance.

bin/kitchen destroy

Removes the docker instance.

bin/kitchen test

Runs all of the stages above in one go: i.e. destroy + converge + verify + destroy.

bin/kitchen login

Gives you SSH access to the instance for manual testing.