feat: support gcp secret manager

apisix/secret/gcp.lua

@@ -0,0 +1,202 @@
+--
+-- 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.
+--
+
+--- GCP Tools.
+local core         = require("apisix.core")
+local http         = require("resty.http")
+local google_oauth = require("apisix.utils.google-cloud-oauth")
+
+local str_sub       = core.string.sub
+local str_find      = core.string.find
+local decode_base64 = ngx.decode_base64
+
+local lrucache = core.lrucache.new({ ttl = 300, count = 8 })
+
+local schema = {
+    type = "object",
+    properties = {
+        auth_config = {
+            type = "object",
+            properties = {
+                client_email = { type = "string" },
+                private_key = { type = "string" },
+                project_id = { type = "string" },
+                token_uri = {
+                    type = "string",
+                    default = "https://oauth2.googleapis.com/token"
+                },
+                scope = {
+                    type = "array",
+                    items = {
+                        type = "string"
+                    },
+                    default = {
+                        "https://www.googleapis.com/auth/cloud-platform"
+                    }
+                },
+                entries_uri = {
+                    type = "string",
+                    default = "https://secretmanager.googleapis.com/v1"
+                },
+            },
+            required = { "client_email", "private_key", "project_id" }
+        },
+        ssl_verify = {
+            type = "boolean",
+            default = true
+        },
+        auth_file = { type = "string" },
+    },
+    oneOf = {
+        { required = { "auth_config" } },
+        { required = { "auth_file" } },
+    },
+}
+
+local _M = {
+    schema = schema
+}
+
+local function fetch_oauth_conf(conf)
+    if conf.auth_config then
+        return conf.auth_config
+    end
+
+    local file_content, err = core.io.get_file(conf.auth_file)
+    if not file_content then
+        return nil, "failed to read configuration, file: " .. conf.auth_file .. ", err: " .. err
+    end
+
+    local config_tab, err = core.json.decode(file_content)
+    if not config_tab then
+        return nil, "config parse failure, data: " .. file_content .. ", err: " .. err
+    end
+
+    local config = {
+        auth_config = {
+            client_email = config_tab.client_email,
+            private_key = config_tab.private_key,
+            project_id = config_tab.project_id
+        }
+    }
+
+    local ok, err = core.schema.check(schema, config)
+    if not ok then
+        return nil, "config parse failure, file: " .. conf.auth_file .. ", err: " .. err
+    end
+
+    return config_tab
+end
+
+
+local function get_secret(oauth, secrets_id)
+    local httpc = http.new()
+
+    local access_token = oauth:generate_access_token()
+    if not access_token then
+        return nil, "failed to get google oauth token"
+    end
+
+    local entries_uri = oauth.entries_uri .. "/projects/" .. oauth.project_id
+                            .. "/secrets/" .. secrets_id .. "/versions/latest:access"
+
+    local res, err = httpc:request_uri(entries_uri, {
+        ssl_verify = oauth.ssl_verify,
+        method = "GET",
+        headers = {
+            ["Content-Type"] = "application/json",
+            ["Authorization"] = (oauth.access_token_type or "Bearer") .. " " .. access_token,
+        },
+    })
+
+    if not res then
+        return nil, err
+    end
+
+    if res.status ~= 200 then
+        return nil, res.body
+    end
+
+    local body, err = core.json.decode(res.body)
+    if not body then
+        return nil, "failed to parse response data, " .. err
+    end
+
+    local payload = body.payload
+    if not payload then
+        return nil, "invalid payload"
+    end
+
+    return decode_base64(payload.data)
+end
+
+
+local function make_request_to_gcp(conf, secrets_id)
+    local auth_config, err = fetch_oauth_conf(conf)
+    if not auth_config then
+        return nil, err
+    end
+
+    local lru_key =  auth_config.client_email .. "#" .. auth_config.project_id
+
+    local oauth, err = lrucache(lru_key, "gcp", google_oauth.new, auth_config, conf.ssl_verify)
+    if not oauth then
+        return nil, "failed to create oauth object, " .. err
+    end
+
+    local secret, err = get_secret(oauth, secrets_id)
+    if not secret then
+        return nil, err
+    end
+
+    return secret
+end
+
+
+function _M.get(conf, key)
+    core.log.info("fetching data from gcp for key: ", key)
+
+    local idx = str_find(key, '/')
+
+    local main_key = idx and str_sub(key, 1, idx - 1) or key
+    if main_key == "" then
+        return nil, "can't find main key, key: " .. key
+    end
+
+    local sub_key = idx and str_sub(key, idx + 1)
+
+    core.log.info("main: ", main_key, sub_key and ", sub: " .. sub_key or "")
+
+    local res, err = make_request_to_gcp(conf, main_key)
+    if not res then
+        return nil, "failed to retrtive data from gcp secret manager: " .. err
+    end
+
+    if not sub_key then
+        return res
+    end
+
+    local data, err = core.json.decode(res)
+    if not data then
+        return nil, "failed to decode result, err: " .. err
+    end
+
+    return data[sub_key]
+end
+
+
+return _M

apisix/utils/google-cloud-oauth.lua

@@ -0,0 +1,130 @@
+--
+-- 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 core = require("apisix.core")
+local type = type
+local setmetatable = setmetatable
+
+local ngx_update_time = ngx.update_time
+local ngx_time = ngx.time
+local ngx_encode_args = ngx.encode_args
+
+local http = require("resty.http")
+local jwt = require("resty.jwt")
+
+
+local function get_timestamp()
+    ngx_update_time()
+    return ngx_time()
+end
+
+
+local _M = {}
+
+
+function _M.generate_access_token(self)
+    if not self.access_token or get_timestamp() > self.access_token_expire_time - 60 then
+        self:refresh_access_token()
+    end
+    return self.access_token
+end
+
+
+function _M.refresh_access_token(self)
+    local http_new = http.new()
+    local res, err = http_new:request_uri(self.token_uri, {
+        ssl_verify = self.ssl_verify,
+        method = "POST",
+        body = ngx_encode_args({
+            grant_type = "urn:ietf:params:oauth:grant-type:jwt-bearer",
+            assertion = self:generate_jwt_token()
+        }),
+        headers = {
+            ["Content-Type"] = "application/x-www-form-urlencoded",
+        },
+    })
+
+    if not res then
+        core.log.error("failed to refresh google oauth access token, ", err)
+        return
+    end
+
+    if res.status ~= 200 then
+        core.log.error("failed to refresh google oauth access token: ", res.body)
+        return
+    end
+
+    res, err = core.json.decode(res.body)
+    if not res then
+        core.log.error("failed to parse google oauth response data: ", err)
+        return
+    end
+
+    self.access_token = res.access_token
+    self.access_token_type = res.token_type
+    self.access_token_expire_time = get_timestamp() + res.expires_in
+end
+
+
+function _M.generate_jwt_token(self)
+    local payload = core.json.encode({
+        iss = self.client_email,
+        aud = self.token_uri,
+        scope = self.scope,
+        iat = get_timestamp(),
+        exp = get_timestamp() + (60 * 60)
+    })
+
+    local jwt_token = jwt:sign(self.private_key, {
+        header = { alg = "RS256", typ = "JWT" },
+        payload = payload,
+    })
+
+    return jwt_token
+end
+
+
+function _M.new(config, ssl_verify)
+    local oauth = {
+        client_email = config.client_email,
+        private_key = config.private_key,
+        project_id = config.project_id,
+        token_uri = config.token_uri or "https://oauth2.googleapis.com/token",
+        auth_uri = config.auth_uri or "https://accounts.google.com/o/oauth2/auth",
+        entries_uri = config.entries_uri,
+        access_token = nil,
+        access_token_type = nil,
+        access_token_expire_time = 0,
+    }
+
+    oauth.ssl_verify = ssl_verify
+
+    if config.scope then
+        if type(config.scope) == "string" then
+            oauth.scope = config.scope
+        end
+
+        if type(config.scope) == "table" then
+            oauth.scope = core.table.concat(config.scope, " ")
+        end
+    end
+
+    return setmetatable(oauth, { __index = _M })
+end
+
+
+return _M

docs/en/latest/terminology/secret.md

@@ -40,6 +40,7 @@ APISIX currently supports storing secrets in the following ways:
 - [Environment Variables](#use-environment-variables-to-manage-secrets)
 - [HashiCorp Vault](#use-hashicorp-vault-to-manage-secrets)
 - [AWS Secrets Manager](#use-aws-secrets-manager-to-manage-secrets)
+- [GCP Secrets Manager](#use-gcp-secrets-manager-to-manage-secrets)
 
 You can use APISIX Secret functions by specifying format variables in the consumer configuration of the following plugins, such as `key-auth`.
 
@@ -293,3 +294,56 @@ curl -i http://127.0.0.1:9080/your_route -H 'apikey: value'
 ```
 
 This will verify whether the `key-auth` plugin is correctly using the key from AWS Secrets Manager.
+
+## Use GCP Secrets Manager to manage secrets
+
+Using the GCP Secrets Manager to manage secrets means you can store the secret information in the GCP service, and reference it using a specific format of variables when configuring plugins. APISIX currently supports integration with the GCP Secrets Manager, and the supported authentication method is [OAuth 2.0](https://developers.google.com/identity/protocols/oauth2).
+
+### Reference Format
+
+```
+$secret://$manager/$id/$secret_name/$key
+```
+
+The reference format is the same as before:
+
+- manager: secrets management service, could be the HashiCorp Vault, AWS, GCP etc.
+- id: APISIX Secrets resource ID, which needs to be consistent with the one specified when adding the APISIX Secrets resource
+- secret_name: the secret name in the secrets management service
+- key: get the value of a property when the value of the secret is a JSON string
+
+### Required Parameters
+
+| Name                    | Required | Default                                                                                                                                                                                              | Description                                                                                                                                                        |
+|-------------------------|----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| auth_config             | True     |                                                                                                                                                                                                      | Either `auth_config` or `auth_file` must be provided.                                                                                                              |
+| auth_config.client_email | True     |                                                                                                                                                                                                    | Email address of the Google Cloud service account.                                                                                                                   |
+| auth_config.private_key | True     |                                                                                                                                                                                                      | Private key of the Google Cloud service account.                                                                                                                   |
+| auth_config.project_id  | True     |                                                                                                                                                                                                      | Project ID in the Google Cloud service account.                                                                                                                    |
+| auth_config.token_uri   | False    | https://oauth2.googleapis.com/token                                                                                                                                                                    | Token URI of the Google Cloud service account.                                                                                                                     |
+| auth_config.entries_uri | False    | https://secretmanager.googleapis.com/v1                                                                                                                                                      | 	The API access endpoint for the Google Secrets Manager.                                                                                                                                |
+| auth_config.scope      | False    | https://www.googleapis.com/auth/cloud-platform | Access scopes of the Google Cloud service account. See [OAuth 2.0 Scopes for Google APIs](https://developers.google.com/identity/protocols/oauth2/scopes) |
+| auth_file               | True     |                                                                                                                                                                                                      | Path to the Google Cloud service account authentication JSON file. Either `auth_config` or `auth_file` must be provided.                                           |
+| ssl_verify              | False    | true                                                                                                                                                                                                 | When set to `true`, enables SSL verification as mentioned in [OpenResty docs](https://github.com/openresty/lua-nginx-module#tcpsocksslhandshake).                  |
+
+You need to configure the corresponding authentication parameters, or specify the authentication file through auth_file, where the content of auth_file is in JSON format.
+
+### Example
+
+Here is a correct configuration example:
+
+```
+curl http://127.0.0.1:9180/apisix/admin/secrets/gcp/1 \
+-H "X-API-KEY: $admin_key" -X PUT -d '
+{
+    "auth_config" : {
+        "client_email": "email@apisix.iam.gserviceaccount.com",
+        "private_key": "private_key",
+        "project_id": "apisix-project",
+        "token_uri": "https://oauth2.googleapis.com/token",
+        "entries_uri": "https://secretmanager.googleapis.com/v1",
+        "scope": ["https://www.googleapis.com/auth/cloud-platform"]
+    }
+}'
+
+```