storage-adapter-consul: initial commit based on MVP from fititnt/ap-a…

…pplication-load-balancer#25

lib/resty/auto-ssl/storage_adapters/consul.lua

@@ -0,0 +1,351 @@
+-- License: Public Domain
+
+---
+-- Requisites:
+--   opm get hamishforbes/lua-resty-consul
+--
+-- @todo: implement expire. Different from Redis, Consul or will persist
+--        keys forever or will have a maximum TTL of 24h. (fititnt, 2019-11-28 19:17 BRT)
+--
+-- @todo: remove dump functions and keep login at at resonable way (fititnt, 2019-11-28 19:17 BRT)
+--
+-- How to test:
+-- Copy this file to /usr/local/share/lua/5.1/resty/auto-ssl/storage_adapters/consul.lua. With ansible would be:
+--    ansible -m copy -a "src=./consul.lua dest=/usr/local/share/lua/5.1/resty/auto-ssl/storage_adapters/consul.lua" aguia-pescadora-delta.etica.ai,aguia-pescadora-echo.etica.ai,aguia-pescadora-foxtrot.etica.ai
+-- Them set the following on your OpenResty, at http context
+--    auto_ssl:set("storage_adapter", "resty.auto-ssl.storage_adapters.consul")
+--
+-- How to document Lua code:
+--   - https://stevedonovan.github.io/ldoc/manual/doc.md.html
+--   - https://keplerproject.github.io/luadoc/manual.html
+--   - http://lua-users.org/wiki/LuaStyleGuide
+--   - http://sputnik.freewisdom.org/en/Coding_Standard
+--
+-- Using ldoc (https://github.com/stevedonovan/LDoc); the lua-doc from keplerproject says it is obsolete (https://github.com/keplerproject/luadoc)
+--    sudo apt install lua-ldoc
+-- Then validate documentation with
+--    ldoc consul.lua
+
+-- I think the path would be /usr/local/share/lua/5.1/resty/auto-ssl/storage_adapters/consul.lua
+-- to work with resty/auto-ssl
+-- And then use this as reference https://github.com/GUI/lua-resty-auto-ssl/blob/master/lib/resty/auto-ssl/storage_adapters/redis.lua
+
+-- Lean lua in an Hour https://www.youtube.com/watch?v=S4eNl1rA1Ns
+-- Definitely an openresty guide/ Hello world https://www.staticshin.com/programming/definitely-an-open-resty-guide/#hello_world
+-- Lua in 15 minutes http://tylerneylon.com/a/learn-lua/
+
+-- Redis equivalent: local redis = require "resty.redis"
+local consul = require('resty.consul')
+
+--------------------------------------------------------------------------------
+-- @todo remove this entire section after finish the heavy debugging
+--       of the consul adapter (fititnt, 2019-11-28 20:21 BRT)
+
+local dumpcache = {}
+
+---
+-- @author https://pastebin.com/A7JScXWk
+-- @param data Anything that need to be dumped
+-- @return string
+function dumpvar(data)
+  -- cache of tables already printed, to avoid infinite recursive loops
+  local tablecache = {}
+  local buffer = ""
+  local padder = "    "
+
+  local function _dumpvar(d, depth)
+      local t = type(d)
+      local str = tostring(d)
+      if (t == "table") then
+          if (tablecache[str]) then
+              -- table already dumped before, so we dont
+              -- dump it again, just mention it
+              buffer = buffer.."<"..str..">\n"
+          else
+              tablecache[str] = (tablecache[str] or 0) + 1
+              buffer = buffer.."("..str..") {\n"
+              for k, v in pairs(d) do
+                  buffer = buffer..string.rep(padder, depth+1).."["..k.."] => "
+                  _dumpvar(v, depth+1)
+              end
+              buffer = buffer..string.rep(padder, depth).."}\n"
+          end
+      elseif (t == "number") then
+          buffer = buffer.."("..t..") "..str.."\n"
+      else
+          buffer = buffer.."("..t..") \""..str.."\"\n"
+      end
+  end
+  _dumpvar(data, 0)
+  return buffer
+end
+
+---
+-- @author fititnt
+local function dump(value, cache_uid)
+  --- print(DataDumper(...), "\n---")
+  -- ngx.log(ngx.ERR, DataDumper(value, varname, false, 2))
+  if (cache_uid) then
+    -- ngx.log(ngx.ERR, 'debug dump function', cache_uid .. os.date("%Y%m%d%H%M"))
+    if (not dumpcache[cache_uid .. os.date("%Y%m%d%H%M")]) then
+      dumpcache[cache_uid .. os.date("%Y%m%d%H%M")] = 1
+      ngx.log(ngx.ERR, dumpvar(value))
+    end
+  else
+    ngx.log(ngx.ERR, dumpvar(value))
+  end
+end
+
+ngx.log(ngx.ERR, "\n\n\n\n\n\n\n\n\n\n---")
+dump({'started', os.date("!%Y-%m-%dT%TZ")})
+--------------------------------------------------------------------------------
+--------------------------------------------------------------------------------
+
+
+-- @module storage_adapter_consul
+local _M = {}
+
+--- Local helper function to, if options have prefix, return a prefixed key name
+-- @param  self
+-- @param  key The umprefixed key name
+-- @return The key prefixed
+local function prefixed_key(self, key)
+  if self.options["prefix"] then
+    -- return self.options["prefix"] .. ":" .. key
+    return self.options["prefix"] .. "/" .. key
+  else
+    return key
+  end
+end
+
+-- @TODO: Discover what to type is the return of _M.new (fititnt, 2019-11-27 22:51 BRT)
+
+--- Returns a stored Key Value from the Consul
+-- @param   auto_ssl_instance
+-- @return  ????
+function _M.new(auto_ssl_instance)
+  local options = auto_ssl_instance:get("consul") or {}
+
+  if not options["prefix"] then
+    options["prefix"] = "lua-resty-auto-ssl"
+  end
+
+  if not options["host"] then
+    options["host"] = "127.0.0.1"
+  end
+
+  if not options["port"] then
+    options["port"] = 8500
+  end
+
+  if not options["connect_timeout"] then
+    options["connect_timeout"] = '60s'
+  end
+
+  if not options["read_timeout"] then
+    options["read_timeout"] = '60s'
+  end
+
+  if not options["ssl"] then
+    options["ssl"] = false
+  end
+
+  if not options["ssl_verify"] then
+    options["ssl_verify"] = true
+  end
+
+  -- local cjson = require "cjson"
+  -- ngx.log(ngx.ERR, '_M.new')
+  -- ngx.log(ngx.ERR, cjson.encode(options))
+  dump({fn = '_M.new', options = options}, '_M.new')
+
+  return setmetatable({ options = options }, { __index = _M })
+end
+
+--- Get the Consul connection, creates one if already does not exist
+-- @param   self
+-- @return  connection
+function _M.get_connection(self)
+  local connection = ngx.ctx.auto_ssl_consul_connection
+  if connection then
+    return connection
+  end
+
+  connection = consul:new(self.options)
+
+  -- local cjson = require "cjson"
+  -- ngx.log(ngx.ERR, '_M.get_connection')
+  -- ngx.log(ngx.ERR, cjson.encode(connection))
+  dump({fn = '_M.get_connection', connection = connection}, '_M.get_connection')
+
+  -- NOTE: From https://github.com/hamishforbes/lua-resty-consul documentation:
+  --      "port Defaults to 8500. Set to 0 if using a unix socket as host."
+  --      redis.lua validate the connection at start, but resty.consul seems
+  --      to validate only on the first request. I will leave this note
+  --      here for now (fititnt, 2019-11-27 23:41 BRT)
+
+  -- local ok, err
+  -- local connect_options = self.options["connect_options"] or {}
+  -- if self.options["socket"] then
+  --   ok, err = connection:connect(self.options["socket"], connect_options)
+  -- else
+  --   ok, err = connection:connect(self.options["host"], self.options["port"], connect_options)
+  -- end
+  -- if not ok then
+  --   return false, err
+  -- end
+
+  -- if self.options["auth"] then
+  --   ok, err = connection:auth(self.options["auth"])
+  --   if not ok then
+  --     return false, err
+  --   end
+  -- end
+
+  -- if self.options["db"] then
+  --   ok, err = connection:select(self.options["db"])
+  --   if not ok then
+  --     return false, err
+  --   end
+  -- end
+
+  -- if not res then
+  --     ngx.log(ngx.ERR, err)
+  --     return
+  -- end
+
+  ngx.ctx.auto_ssl_consul_connection = connection
+  return connection
+end
+
+-- Note: _M.setup() on redis.lua is empty, no arguments, no return value
+function _M.setup()
+end
+
+--- Returns a stored Key Value from the Consul
+-- @param  self
+-- @param  key   The umprefixed key name
+-- @return The value of saved key (if exists)
+function _M.get(self, key)
+  local connection, connection_err = self:get_connection()
+  local value = nil
+  if connection_err then
+    return nil, connection_err
+  end
+
+  -- Redis use get, Consul use get_key
+  -- Redis 'res' is value or nil; Consul is a lua-resty-http response object
+  local res, err = connection:get_key(prefixed_key(self, key))
+  -- if res == ngx.null then
+  -- if res.status == 404 then
+  --  -- ngx.log(ngx.ERR, 'storage_adapter.consul._M.get: connection error:', err)
+  --  value = nil
+  --else
+  if res.status ~= 404 and res.body[0] ~= nil and res.body[0]['Value'] ~= null then
+    value = res.body[0]['Value']
+  end
+
+  dump({fn = '_M.get', key=key, res=res, err=err, value=value}, '_M.get')
+
+  return value, err
+end
+
+--- Store a key-value on the Consul
+--
+-- @todo  There is a difference betwen connection:put (Redis) and from consul
+--        from the first parameter. This should be checked
+--
+-- @todo  options param still not used, but will leave it here for now (fititnt, 2019-11-28 20:15 BRT)
+--
+-- @param  self
+-- @param  key      The umprefixed key name
+-- @param  value    The values
+-- @param  options  The values
+-- @return ok       Boolean if result was ok or not
+-- @return res  lua-resty-http response object. On error returns nil
+-- @return err  On error returns an error message
+function _M.set(self, key, value, options)
+  local connection, connection_err = self:get_connection()
+  if connection_err then
+    return false, connection_err
+  end
+
+  key = prefixed_key(self, key)
+
+  -- Redis use set, Consul use put_key:
+  -- local ok, err = connection:put_key(key, value)
+  local res, err = connection:put_key(key, value)
+
+  -- Know issue: not implemented way to expire key at this moment.
+  -- The following was from redis.lua
+  -- if ok then
+  --   if options and options["exptime"] then
+  --     local _, expire_err = connection:expire(key, options["exptime"])
+  --     if expire_err then
+  --       ngx.log(ngx.ERR, "auto-ssl: failed to set expire: ", expire_err)
+  --     end
+  --   end
+  -- end
+
+  dump({fn = '_M.set', key=key, value=value, res=res, err=err}, '_M.set')
+  return res, err
+end
+
+--- Delete a value from Consul based on the unprefixed key
+-- @param  self
+-- @param  key  The umprefixed key name
+-- @return res  lua-resty-http response object. On error returns nil
+-- @return err  On error returns an error message
+function _M.delete(self, key)
+  local connection, connection_err = self:get_connection()
+  if connection_err then
+    -- ngx.log(ngx.EMERG, '_M.delete: ', connection_err)
+    ngx.log(ngx.EMERG, 'storage_adapter.consul._M.delete: connection error:', err)
+    return false, connection_err
+  end
+
+  -- local cjson = require "cjson"
+  -- ngx.log(ngx.ERR, '_M.delete: ', connection_err)
+  -- ngx.log(ngx.ERR, cjson.encode(connection_err))
+
+  -- Redis use del, Consul uses delete_key
+  return connection:delete_key(prefixed_key(self, key))
+end
+
+-- TODO: finish _M.keys_with_suffix (fititnt, 2019-27-23:01 BRT)
+--- Returns a stored Key Value from the Consul
+-- @param  self
+-- @param  suffix   The umprefixed key name
+-- @return keys     The keys
+-- @return err  On error returns an error message
+function _M.keys_with_suffix(self, suffix)
+  local connection, connection_err = self:get_connection()
+  if connection_err then
+    ngx.log(ngx.EMERG, '_M.keys_with_suffix: ', connection_err)
+    return false, connection_err
+  end
+
+  -- Redis use keys, Consul uses list_keys
+  -- local keys, err = connection:keys(prefixed_key(self, "*" .. suffix))
+  local keys, err = connection:list_keys(prefixed_key(self, "*" .. suffix))
+
+  if keys and self.options["prefix"] then
+    local unprefixed_keys = {}
+    -- First character past the prefix and a colon
+    local offset = string.len(self.options["prefix"]) + 2
+
+    for _, key in ipairs(keys) do
+      local unprefixed = string.sub(key, offset)
+      table.insert(unprefixed_keys, unprefixed)
+    end
+
+    keys = unprefixed_keys
+  end
+
+  dump({fn = '_M.keys_with_suffix', keys = keys, err = err}, '_M.keys_with_suffix')
+
+  return keys, err
+end
+
+
+return _M