apisix/cli/file.lua

--
-- Licensed to the Apache Software Foundation (ASF) under one or more
-- contributor license agreements.  See the NOTICE file distributed with
-- this work for additional information regarding copyright ownership.
-- The ASF licenses this file to You under the Apache License, Version 2.0
-- (the "License"); you may not use this file except in compliance with
-- the License.  You may obtain a copy of the License at
--
--     http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.
--

local yaml = require("tinyyaml")
local profile = require("apisix.core.profile")
local util = require("apisix.cli.util")

local pairs = pairs
local type = type
local tonumber = tonumber
local getmetatable = getmetatable
local getenv = os.getenv
local str_gmatch = string.gmatch
local str_find = string.find
local str_sub = string.sub

local _M = {}
local exported_vars


function _M.get_exported_vars()
    return exported_vars
end


local function is_empty_yaml_line(line)
    return line == '' or str_find(line, '^%s*$') or str_find(line, '^%s*#')
end


local function tab_is_array(t)
    local count = 0
    for k, v in pairs(t) do
        count = count + 1
    end

    return #t == count
end


local function resolve_conf_var(conf)
    for key, val in pairs(conf) do
        if type(val) == "table" then
            local ok, err = resolve_conf_var(val)
            if not ok then
                return nil, err
            end

        elseif type(val) == "string" then
            local err
            local var_used = false
            -- we use '${{var}}' because '$var' and '${var}' are taken
            -- by Nginx
            local new_val = val:gsub("%$%{%{%s*([%w_]+)%s*%}%}", function(var)
                local v = getenv(var)
                if v then
                    if not exported_vars then
                        exported_vars = {}
                    end

                    exported_vars[var] = v
                    var_used = true
                    return v
                end

                err = "failed to handle configuration: " ..
                      "can't find environment variable " .. var
                return ""
            end)

            if err then
                return nil, err
            end

            if var_used then
                if tonumber(new_val) ~= nil then
                    new_val = tonumber(new_val)
                elseif new_val == "true" then
                    new_val = true
                elseif new_val == "false" then
                    new_val = false
                end
            end

            conf[key] = new_val
        end
    end

    return true
end


local function tinyyaml_type(t)
    local mt = getmetatable(t)
    if mt then
        return mt.__type
    end
end


local function merge_conf(base, new_tab, ppath)
    ppath = ppath or ""

    for key, val in pairs(new_tab) do
        if type(val) == "table" then
            if tinyyaml_type(val) == "null" then
                base[key] = nil

            elseif tab_is_array(val) then
                base[key] = val

            else
                if base[key] == nil then
                    base[key] = {}
                end

                local ok, err = merge_conf(
                    base[key],
                    val,
                    ppath == "" and key or ppath .. "->" .. key
                )
                if not ok then
                    return nil, err
                end
            end
        else
            local type_val = type(val)

            if base[key] == nil then
                base[key] = val
            elseif type(base[key]) ~= type_val then
                if (ppath == "nginx_config" or str_sub(ppath, 1, 14) == "nginx_config->") and
                    (type_val == "number" or type_val == "string")
                then
                    base[key] = val
                else
                    local path = ppath == "" and key or ppath .. "->" .. key
                    return nil, "failed to merge, path[" .. path ..  "] expect: " ..
                                type(base[key]) .. ", but got: " .. type_val
                end
            else
                base[key] = val
            end
        end
    end

    return base
end


function _M.read_yaml_conf(apisix_home)
    if apisix_home then
        profile.apisix_home = apisix_home .. "/"
    end

    local local_conf_path = profile:yaml_path("config-default")
    local default_conf_yaml, err = util.read_file(local_conf_path)
    if not default_conf_yaml then
        return nil, err
    end

    local default_conf = yaml.parse(default_conf_yaml)
    if not default_conf then
        return nil, "invalid config-default.yaml file"
    end

    local_conf_path = profile:yaml_path("config")
    local user_conf_yaml, err = util.read_file(local_conf_path)
    if not user_conf_yaml then
        return nil, err
    end

    local is_empty_file = true
    for line in str_gmatch(user_conf_yaml .. '\n', '(.-)\r?\n') do
        if not is_empty_yaml_line(line) then
            is_empty_file = false
            break
        end
    end

    if not is_empty_file then
        local user_conf = yaml.parse(user_conf_yaml)
        if not user_conf then
            return nil, "invalid config.yaml file"
        end

        local ok, err = resolve_conf_var(user_conf)
        if not ok then
            return nil, err
        end

        ok, err = merge_conf(default_conf, user_conf)
        if not ok then
            return nil, err
        end
    end

    return default_conf
end


return _M