Bypass 3scale in case it is unreachable

nginx.conf

http {
  # add this near the top of the HTTP section
  lua_shared_dict healthcheck 1m;
  lua_socket_log_errors off;

  # healthchecks are HTTP only
  upstream threescale_healthcheck {
    server su1.3scale.net:80;
  }
  
  # healthcheck worker
  init_worker_by_lua '
    local hc = require "resty.upstream.healthcheck"

    local ok, err = hc.spawn_checker{
      shm = "healthcheck",
      upstream = "threescale_healthcheck",
      type = "http",

      http_req = "GET /status HTTP/1.0\\r\\nHost: su1.3scale.net\\r\\n\\r\\n",

      interval = 2000,              -- run the check cycle every 2 sec
      timeout = 5000,               -- 5 sec is the timeout for network operations
      fall = 2,                     -- # of successive failures before turning a peer down
      rise = 2,                     -- # of successive successes before turning a peer up
      valid_statuses = {200, 302},  -- a list valid HTTP status code
      concurrency = 1,              -- concurrency level for test requests
    }
    if not ok then
      ngx.log(ngx.ERR, "failed to spawn health checker: ", err)
      return
    end
  ';
  
  location = /out_of_band_authrep_action {
    
    # wrap the code in the content_by_lua in a conditional
    # like in the example below
    content_by_lua '
      if ngx.var.bypass ~= "true" then
        -- previous content of the "content_by_lua"
      end
    ';
  }
}

nginx.lua

-- Modifications to the nginx.lua file
--------------------------------------

-- require ngx.upstream module, included in openresty
local upstream  = require "ngx.upstream"

-----------------------------

-- healthcheck helper
local function is_3scale_up()
  local peers, err = upstream.get_primary_peers("threescale_healthcheck")
  local peer = peers[1]
  if peer.down then
    ngx.log(ngx.WARN, "3scale is unreachable now")
    return false
  else
    ngx.log(ngx.INFO, "3scale is UP")
    return true
  end
end

-----------------------------

-- do a search for the following line "if is_known ~= 200 then"
-- and add the following piece of code below every ocurrence
if not is_3scale_up() then
  ngx.var.bypass = "true"
  return
end  

How to modify your configuration files to use this snippet:

In the nginx.conf:

• add the following new lines to the http section
• modify the out_of_band location or locations to wrap their contents in a conditional like here

In the nginx.lua:

• add the following new lines
• then search for if is_known ~=200 then and add the following right below every ocurrence of that line