412cd70d3a
Adds the ability to create alternative backends. Alternative backends enable traffic shaping by sharing a single location but routing to different backends depending on the TrafficShapingPolicy defined by AlternativeBackends. When the list of upstreams and servers are retrieved, we then call mergeAlternativeBackends which iterates through the paths of every ingress and checks if the backend supporting the path is a AlternativeBackend. If so, we then iterate through the map of servers and find the real backend that the AlternativeBackend should fall under. Once found, the AlternativeBackend is embedded in the list of VirtualBackends for the real backend. If no matching real backend for a AlternativeBackend is found, then the AlternativeBackend is deleted as it cannot be backed by any server.
117 lines
3 KiB
Lua
117 lines
3 KiB
Lua
local string_len = string.len
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local string_sub = string.sub
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local resty_str = require("resty.string")
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local resty_sha1 = require("resty.sha1")
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local resty_md5 = require("resty.md5")
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local _M = {}
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function _M.get_nodes(endpoints)
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local nodes = {}
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local weight = 1
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for _, endpoint in pairs(endpoints) do
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local endpoint_string = endpoint.address .. ":" .. endpoint.port
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nodes[endpoint_string] = weight
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end
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return nodes
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end
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local function hash_digest(hash_factory, message)
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local hash = hash_factory:new()
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if not hash then
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return nil, "failed to create object"
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end
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local ok = hash:update(message)
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if not ok then
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return nil, "failed to add data"
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end
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local binary_digest = hash:final()
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if binary_digest == nil then
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return nil, "failed to create digest"
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end
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return resty_str.to_hex(binary_digest), nil
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end
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function _M.sha1_digest(message)
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return hash_digest(resty_sha1, message)
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end
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function _M.md5_digest(message)
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return hash_digest(resty_md5, message)
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end
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-- given an Nginx variable i.e $request_uri
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-- it returns value of ngx.var[request_uri]
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function _M.lua_ngx_var(ngx_var)
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local var_name = string_sub(ngx_var, 2)
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if var_name:match("^%d+$") then
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var_name = tonumber(var_name)
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end
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return ngx.var[var_name]
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end
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-- this implementation is taken from
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-- https://web.archive.org/web/20131225070434/http://snippets.luacode.org/snippets/Deep_Comparison_of_Two_Values_3
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-- and modified for use in this project
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local function deep_compare(t1, t2, ignore_mt)
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local ty1 = type(t1)
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local ty2 = type(t2)
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if ty1 ~= ty2 then return false end
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-- non-table types can be directly compared
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if ty1 ~= 'table' and ty2 ~= 'table' then return t1 == t2 end
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-- as well as tables which have the metamethod __eq
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local mt = getmetatable(t1)
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if not ignore_mt and mt and mt.__eq then return t1 == t2 end
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for k1,v1 in pairs(t1) do
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local v2 = t2[k1]
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if v2 == nil or not deep_compare(v1,v2) then return false end
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end
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for k2,v2 in pairs(t2) do
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local v1 = t1[k2]
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if v1 == nil or not deep_compare(v1,v2) then return false end
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end
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return true
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end
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_M.deep_compare = deep_compare
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function _M.is_blank(str)
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return str == nil or string_len(str) == 0
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end
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-- this implementation is taken from:
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-- https://github.com/luafun/luafun/blob/master/fun.lua#L33
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-- SHA: 04c99f9c393e54a604adde4b25b794f48104e0d0
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local function deepcopy(orig)
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local orig_type = type(orig)
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local copy
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if orig_type == 'table' then
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copy = {}
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for orig_key, orig_value in next, orig, nil do
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copy[deepcopy(orig_key)] = deepcopy(orig_value)
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end
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else
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copy = orig
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end
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return copy
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end
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_M.deepcopy = deepcopy
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local function tablelength(T)
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local count = 0
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for _ in pairs(T) do
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count = count + 1
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end
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return count
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end
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_M.tablelength = tablelength
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-- replaces special character value a with value b for all occurences in a string
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local function replace_special_char(str, a, b)
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return string.gsub(str, "%" .. a, b)
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end
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_M.replace_special_char = replace_special_char
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return _M
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