Class: Kamal::Cli::Proxy::LoadbalancerClaim

Inherits:
Object
  • Object
show all
Defined in:
lib/kamal/cli/proxy/loadbalancer_claim.rb

Overview

Ownership bookkeeping for a load balancer host that more than one kamal app may be deploying to. Kamal only ever sees one deploy.yml at a time, so the other apps are visible solely through the files they left on the host.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(host, sshkit) ⇒ LoadbalancerClaim

Returns a new instance of LoadbalancerClaim.



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# File 'lib/kamal/cli/proxy/loadbalancer_claim.rb', line 8

def initialize(host, sshkit)
  @host = host
  @sshkit = sshkit
end

Instance Attribute Details

#host ⇒ Object (readonly)

Returns the value of attribute host.



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# File 'lib/kamal/cli/proxy/loadbalancer_claim.rb', line 5

def host
  @host
end

#sshkit ⇒ Object (readonly)

Returns the value of attribute sshkit.



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# File 'lib/kamal/cli/proxy/loadbalancer_claim.rb', line 5

def sshkit
  @sshkit
end

Instance Method Details

#claim_run_config(replace: false) ⇒ Object

Every app sharing a load balancer boots the same container, so their proxy/run configurations have to agree. A mismatch owned by another app is an error; a mismatch owned by this app is ordinary drift, reported the same way the per-host proxy reports it and fixed by kamal proxy reboot.



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# File 'lib/kamal/cli/proxy/loadbalancer_claim.rb', line 33

def claim_run_config(replace: false)
  record = capture_with_info(*commands.read_run_config_record, raise_on_non_zero_exit: false).strip

  if record.present?
    *owner_parts, digest = record.split(" ")
    owner = owner_parts.join(" ")

    if digest != config.run_config_digest
      if owner != config.owner_token
        raise "The load balancer on #{host} was booted by #{repository_in(owner)} with a different proxy/run configuration. " \
              "Apps sharing a load balancer must agree on proxy/run - align the configurations or use a different load balancer host."
      elsif !replace
        warn "The load balancer on #{host} is running with a configuration that no longer matches the deploy config - " \
             "run `kamal proxy reboot` to apply the new configuration."
        return
      end
    end
  end

  execute *commands.ensure_directory
  upload! StringIO.new(config.run_config_record), config.run_config_file
end

#claim_service ⇒ Object

The load balancer registers services under the bare service name, so a second app - or a second destination of this app - deploying the same name would silently take over its routes. Claim the name on first deploy and fail loudly rather than quietly stealing it.



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# File 'lib/kamal/cli/proxy/loadbalancer_claim.rb', line 17

def claim_service
  owner = capture_with_info(*commands.read_service_owner, raise_on_non_zero_exit: false).strip

  if owner.present? && owner != config.owner_token
    raise "Service '#{config.config.service}' is already registered on the load balancer at #{host} by #{repository_in(owner)}. " \
          "Deploying would take over its routes - rename this app's service or use a different load balancer."
  end

  execute *commands.ensure_services_directory
  upload! StringIO.new(config.owner_token), config.service_owner_file
end