Nginx Validation JWT

nginx_validation_jwt.lua

    access_by_lua_block {
        local http = require "resty.http"
        local httpc = http.new()

        -- Fetch the JWT token from Authorization header
        local auth_header = ngx.var.http_Authorization
        if auth_header then
            local _, jwt_token = auth_header:find("Bearer%s+(.+)")
            if jwt_token then
                -- Perform subrequest to your API endpoint for token validation
                local res, err = httpc:request_uri("https://your-api-domain.com/validate", {
                    method = "POST",
                    body = jwt_token,
                    headers = {
                        ["Content-Type"] = "application/json",
                    }
                })

                -- If token validation is successful, return
                if res and res.status == 200 then
                    return
                end
            end
        end

        -- If token is invalid or missing, respond with error
        ngx.header.content_type = "application/json"
        ngx.status = 403
        ngx.say('{"error":"Invalid JWT token"}')
        ngx.exit(ngx.HTTP_FORBIDDEN)
    }