wehub-resource-sync
71 lines
2.5 KiB
Lua
71 lines
2.5 KiB
Lua
local normalize_ip = require("kong.tools.ip").normalize_ip
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local dns_client
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--- Load and setup the DNS client according to the provided configuration.
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-- @param conf (table) Kong configuration
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-- @return the initialized `resty.dns.client` module, or an error
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local setup_client = function(conf)
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if not dns_client then
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dns_client = require "kong.resty.dns.client"
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end
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conf = conf or {}
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local servers = {}
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-- servers must be reformatted as name/port sub-arrays
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if conf.dns_resolver then
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for i, server in ipairs(conf.dns_resolver) do
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local s = normalize_ip(server)
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servers[i] = { s.host, s.port or 53 } -- inserting port if omitted
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end
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end
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local opts = {
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hosts = conf.dns_hostsfile,
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resolvConf = nil, -- defaults to system resolv.conf
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nameservers = servers, -- provided list or taken from resolv.conf
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enable_ipv6 = true, -- allow for ipv6 nameserver addresses
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retrans = nil, -- taken from system resolv.conf; attempts
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timeout = nil, -- taken from system resolv.conf; timeout
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validTtl = conf.dns_valid_ttl, -- ttl in seconds overriding ttl of valid records
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badTtl = conf.dns_error_ttl, -- ttl in seconds for dns error responses (except 3 - name error)
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emptyTtl = conf.dns_not_found_ttl, -- ttl in seconds for empty and "(3) name error" dns responses
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staleTtl = conf.dns_stale_ttl, -- ttl in seconds for records once they become stale
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cacheSize = conf.dns_cache_size, -- maximum number of records cached in memory
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order = conf.dns_order, -- order of trying record types
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noSynchronisation = conf.dns_no_sync,
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}
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-- new dns client
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if ngx.shared.kong_dns_cache and _G.busted_new_dns_client ~= false then
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servers = {}
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if conf.resolver_address then
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for i, server in ipairs(conf.resolver_address) do
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local s = normalize_ip(server)
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servers[i] = { s.host, s.port or 53 } -- inserting port if omitted
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end
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end
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opts = {
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nameservers = servers,
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hosts = conf.resolver_hosts_file,
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family = conf.resolver_family,
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valid_ttl = conf.resolver_valid_ttl,
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error_ttl = conf.resolver_error_ttl,
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stale_ttl = conf.resolver_stale_ttl,
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cache_size = conf.resolver_lru_cache_size,
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enable_ipv6 = true, -- allow for IPv6 nameserver addresses
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}
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end
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assert(dns_client.init(opts))
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return dns_client
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end
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return setup_client
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