kong/go-plugins

A collection of Kong plugins written in Go

⚠️ This repository is no longer maintained. Examples are now in the go-pdk repo

Kong Go Plugins

Example code of Kong plugins written in Go. These are not plugins intended for production use, but rather small examples to get you started writing your own:

• go-hello: a "hello world" plugin, which reads a request header and sets a response header.
• go-hello-lm: same as the previous as a loadble module to use with the go-pluginserver.
• go-log: a reimplementation of Kong's file-log plugin in Go. shows the use of go I/O, goroutines and long-lived globals.
• go-log-lm: same as go-log but built as a loadable module to use with the go-pluginserver.

go-plugins's Issues

Kong is getting stop again and again

kong | 2022/08/19 13:43:56 [notice] 30#0: signal 17 (SIGCHLD) received from 91
kong | 2022/08/19 13:43:56 [notice] 30#0: *14 [kong] go.lua:95 go-pluginserver terminated: exit 2, context: ngx.timer
kong | 2022/08/19 13:43:56 [notice] 30#0: *14 [kong] go.lua:84 Starting go-pluginserver, context: ngx.timer

I'm facing this issue, kong is getting stop and stop again and again , how can I resolve this issue??

Unit test framework for go plugins

Is there a way to test the plugins without actually deploying or running the gateway.
Mostly regarding the context of unit testing.

Can go plugin has daos/schema structure just like LUA plugin?

I am trying to develop my plugins with GO, and wondering if go-plugins have ability to interactive with Kong's database/caches by using dao.lua / schema.lua just like what LUA does?
For example:
https://docs.konghq.com/gateway/latest/plugin-development/access-the-datastore/
https://github.com/Kong/kong/blob/master/kong/plugins/basic-auth/daos.lua
https://github.com/Kong/kong/blob/master/kong/plugins/basic-auth/schema.lua

Consider moving plugins to separate folders to make valid go module

At the moment all plugin examples are situated at the root of the repo which is bad practice as the code is not a valid go module. There are multiple main files and other conflicting declarations meaning that the you cannot generically build the repo or write test files.

For instance write a test file and see the following errors:

 go build .
# github.com/Kong/go-plugins
.\go-hello.go:20:5: Version redeclared in this block
        .\go-hello-lm.go:15:5: other declaration of Version
.\go-hello.go:21:5: Priority redeclared in this block
        .\go-hello-lm.go:16:5: other declaration of Priority
.\go-hello.go:23:6: Config redeclared in this block
        .\go-hello-lm.go:18:6: other declaration of Config
.\go-hello.go:27:6: New redeclared in this block
        .\go-hello-lm.go:22:6: other declaration of New
.\go-log-lm.go:11:6: Config redeclared in this block
        .\go-hello-lm.go:18:6: other declaration of Config
.\go-log-lm.go:19:6: New redeclared in this block
        .\go-hello-lm.go:22:6: other declaration of New
.\go-log.go:29:6: main redeclared in this block
        .\go-hello.go:16:6: other declaration of main
.\go-log.go:35:6: Config redeclared in this block
        .\go-hello-lm.go:18:6: other declaration of Config
.\go-log.go:48:5: fileDescriptors redeclared in this block
        .\go-log-lm.go:16:5: other declaration of fileDescriptors
.\go-log.go:49:5: channels redeclared in this block
        .\go-log-lm.go:17:5: other declaration of channels
.\go-log.go:49:5: too many errors

It would be good it these examples followed go best practices to separate main files into separate folders.

How to install this plugin?

The code is very simple and clear for understanding, but I have question about how to install this plugin.

My kong version is 2.2.1.

Testing Go Plugins

How does one go about writing unit/integration tests for go plugins? Examples are in this repo but no test examples.

I know lua plugins have kong-pongo, is there a go variant?

go-pluginserver error die loop

error.log:
2020/04/09 20:42:49 [notice] 32346#0: signal 17 (SIGCHLD) received from 19941
2020/04/09 20:42:49 [notice] 32346#0: *13 [kong] go.lua:95 go-pluginserver terminated: exit 0, context: ngx.timer
centos 7

go-pluginserver -version
Version: development
Runtime Version: go1.13.5

go-pluginserver -dump-plugin-info go-hello -plugins-directory $(pwd)
2020/04/09 20:47:47 failed to open plugin go-hello: plugin.Open("/root/go-plugins/go-hello"): plugin was built with a different version of package internal/cpu

How to use these plugins?

How to use these plugins? Any example or the guide will be of great help.
I followed below steps:

1. added go_plugins_dir = /usr/local/kong/goplugins inside the kong.conf file
2. created the folder at /usr/local/kong/goplugins and added go-hello.go from https://github.com/Kong/go-plugins
3. Tried finding the same through curl localhost:8001 but can not find go-hello

output of above curl
{"plugins":{"enabled_in_cluster":["jwt-custom","prometheus","rate-limiting","syslog","file-log"],"available_on_server":{"correlation-id":true,"pre-function":true,"cors":true,"ldap-auth":true,"loggly":true,"hmac-auth":true,"zipkin":true,"request-size-limiting":true,"azure-functions":true,"request-transformer":true,"oauth2":true,"response-transformer":true,"ip-restriction":true,"statsd":true,"jwt":true,"proxy-cache":true,"basic-auth":true,"key-auth":true,"http-log":true,"ab-user":true,"jwt-custom":true,"datadog":true,"tcp-log":true,"rate-limiting":true,"post-function":true,"prometheus":true,"acl":true,"syslog":true,"file-log":true,"acme":true,"udp-log":true,"response-ratelimiting":true,"aws-lambda":true,"session":true,"bot-detection":true,"request-termination":true}},"tagline":"Welcome to kong","configuration":{"plugins":["bundled","jwt-custom","ab-user"],"admin_listen":["0.0.0.0:8001","0.0.0.0:8444 ssl"],"lua_ssl_verify_depth":1,"prefix":"\/usr\/local\/kong","nginx_conf":"\/usr\/local\/kong\/nginx.conf","cassandra_username":"kong","nginx_events_directives":[{"value":"auto","name":"worker_connections"},{"value":"on","name":"multi_accept"}],"admin_ssl_cert_key":"\/usr\/local\/kong\/ssl\/admin-kong-default.key","dns_resolver":{},"nginx_upstream_keepalive_requests":"100","nginx_http_upstream_directives":[{"value":"100","name":"keepalive_requests"},{"value":"60s","name":"keepalive_timeout"},{"value":"60","name":"keepalive"}],"nginx_main_daemon":"on","stream_proxy_ssl_enabled":false,"nginx_acc_logs":"\/usr\/local\/kong\/logs\/access.log","pg_semaphore_timeout":60000,"proxy_listen":["0.0.0.0:8000 reuseport backlog=16384","0.0.0.0:8443 http2 ssl reuseport backlog=16384"],"client_ssl_cert_default":"\/usr\/local\/kong\/ssl\/kong-default.crt","go_pluginserver_exe":"\/usr\/local\/bin\/go-pluginserver","dns_no_sync":false,"db_update_propagation":0,"stream_listen":["off"],"nginx_err_logs":"\/usr\/local\/kong\/logs\/error.log","cassandra_port":9042,"headers":["server_tokens","latency_tokens"],"nginx_http_client_max_body_size":"0","status_listen":["off"],"cassandra_lb_policy":"RequestRoundRobin","cluster_control_plane":"127.0.0.1:8005","nginx_http_ssl_prefer_server_ciphers":"off","pg_database":"kong","lua_package_cpath":"","admin_acc_logs":"\/usr\/local\/kong\/logs\/admin_access.log","cassandra_refresh_frequency":60,"nginx_pid":"\/usr\/local\/kong\/pids\/nginx.pid","nginx_main_worker_rlimit_nofile":"auto","admin_access_log":"logs\/admin_access.log","proxy_listeners":[{"listener":"0.0.0.0:8000 reuseport backlog=16384","proxy_protocol":false,"reuseport":true,"deferred":false,"ssl":false,"ip":"0.0.0.0","backlog=16384":true,"http2":false,"port":8000,"bind":false},{"listener":"0.0.0.0:8443 ssl http2 reuseport backlog=16384","proxy_protocol":false,"reuseport":true,"deferred":false,"ssl":true,"ip":"0.0.0.0","backlog=16384":true,"http2":true,"port":8443,"bind":false}],"db_cache_warmup_entities":["services","plugins"],"enabled_headers":{"latency_tokens":true,"X-Kong-Response-Latency":true,"Server":true,"X-Kong-Admin-Latency":true,"X-Kong-Upstream-Status":false,"Via":true,"X-Kong-Proxy-Latency":true,"server_tokens":true,"X-Kong-Upstream-Latency":true},"nginx_http_ssl_protocols":"TLSv1.2 TLSv1.3","db_cache_ttl":0,"nginx_events_multi_accept":"on","admin_ssl_cert_default":"\/usr\/local\/kong\/ssl\/admin-kong-default.crt","pg_ssl":false,"status_access_log":"off","cluster_listeners":[{"listener":"0.0.0.0:8005","proxy_protocol":false,"reuseport":false,"backlog=%d+":false,"deferred":false,"ssl":false,"ip":"0.0.0.0","port":8005,"http2":false,"bind":false}],"kong_env":"\/usr\/local\/kong\/.kong_env","cassandra_schema_consensus_timeout":60000,"log_level":"notice","admin_ssl_cert_key_default":"\/usr\/local\/kong\/ssl\/admin-kong-default.key","real_ip_recursive":"off","cassandra_repl_factor":1,"nginx_main_worker_processes":"auto","router_consistency":"strict","pg_port":5432,"cassandra_keyspace":"kong","ssl_cert_default":"\/usr\/local\/kong\/ssl\/kong-default.crt","nginx_http_ssl_session_timeout":"1d","error_default_type":"text\/plain","role":"traditional","client_ssl":false,"trusted_ips":{},"nginx_events_worker_connections":"auto","nginx_supstream_directives":{},"ssl_cert_key":"\/usr\/local\/kong\/ssl\/kong-default.key","pg_user":"kong","pg_password":"******","ssl_ciphers":"ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384","nginx_admin_directives":{},"nginx_upstream_keepalive_timeout":"60s","nginx_http_directives":[{"value":"0","name":"client_max_body_size"},{"value":"off","name":"ssl_prefer_server_ciphers"},{"value":"8k","name":"client_body_buffer_size"},{"value":"TLSv1.2 TLSv1.3","name":"ssl_protocols"},{"value":"on","name":"ssl_session_tickets"},{"value":"1d","name":"ssl_session_timeout"},{"value":"prometheus_metrics 5m","name":"lua_shared_dict"}],"pg_host":"hawkeye-qa.cavqxjfmp25f.ap-south-1.rds.amazonaws.com","nginx_kong_stream_conf":"\/usr\/local\/kong\/nginx-kong-stream.conf","ssl_cert_key_default":"\/usr\/local\/kong\/ssl\/kong-default.key","go_plugins_dir":"\/usr\/local\/kong\/goplugins","db_update_frequency":5,"dns_order":["LAST","SRV","A","CNAME"],"dns_error_ttl":1,"nginx_optimizations":true,"nginx_http_upstream_keepalive_timeout":"60s","pg_timeout":60000,"nginx_http_upstream_keepalive_requests":"100","database":"postgres","nginx_upstream_keepalive":"60","nginx_worker_processes":"auto","nginx_http_status_directives":{},"lua_package_path":".\/?.lua;.\/?\/init.lua;","router_update_frequency":1,"upstream_keepalive":60,"pg_max_concurrent_queries":0,"proxy_ssl_enabled":true,"nginx_http_upstream_keepalive":"60","lua_socket_pool_size":30,"mem_cache_size":"128m","loaded_plugins":{"correlation-id":true,"pre-function":true,"cors":true,"ldap-auth":true,"loggly":true,"hmac-auth":true,"zipkin":true,"request-size-limiting":true,"azure-functions":true,"request-transformer":true,"oauth2":true,"response-transformer":true,"syslog":true,"statsd":true,"acme":true,"proxy-cache":true,"basic-auth":true,"key-auth":true,"http-log":true,"jwt":true,"bot-detection":true,"ab-user":true,"tcp-log":true,"session":true,"post-function":true,"datadog":true,"acl":true,"ip-restriction":true,"file-log":true,"jwt-custom":true,"udp-log":true,"response-ratelimiting":true,"aws-lambda":true,"rate-limiting":true,"prometheus":true,"request-termination":true},"db_resurrect_ttl":30,"cassandra_data_centers":["dc1:2","dc2:3"],"cassandra_consistency":"ONE","client_max_body_size":"0","admin_error_log":"logs\/error.log","pg_ssl_verify":false,"dns_not_found_ttl":30,"nginx_http_ssl_session_tickets":"on","dns_stale_ttl":4,"ssl_cipher_suite":"intermediate","cassandra_repl_strategy":"SimpleStrategy","status_error_log":"logs\/status_error.log","nginx_http_client_body_buffer_size":"8k","kic":false,"cluster_listen":["0.0.0.0:8005"],"nginx_kong_conf":"\/usr\/local\/kong\/nginx-kong.conf","real_ip_header":"X-Real-IP","dns_hostsfile":"\/etc\/hosts","admin_listeners":[{"listener":"0.0.0.0:8001","proxy_protocol":false,"reuseport":false,"backlog=%d+":false,"deferred":false,"ssl":false,"ip":"0.0.0.0","port":8001,"http2":false,"bind":false},{"listener":"0.0.0.0:8444 ssl","proxy_protocol":false,"reuseport":false,"backlog=%d+":false,"deferred":false,"ssl":true,"ip":"0.0.0.0","port":8444,"http2":false,"bind":false}],"ssl_cert_csr_default":"\/usr\/local\/kong\/ssl\/kong-default.csr","ssl_cert":"\/usr\/local\/kong\/ssl\/kong-default.crt","nginx_proxy_real_ip_recursive":"off","nginx_status_directives":{},"cassandra_ssl_verify":false,"cassandra_ssl":false,"admin_ssl_cert":"\/usr\/local\/kong\/ssl\/admin-kong-default.crt","proxy_error_log":"logs\/error.log","nginx_sproxy_directives":{},"nginx_proxy_directives":[{"value":"X-Real-IP","name":"real_ip_header"},{"value":"off","name":"real_ip_recursive"}],"nginx_daemon":"on","anonymous_reports":true,"cassandra_timeout":60000,"nginx_main_directives":[{"value":"on","name":"daemon"},{"value":"auto","name":"worker_rlimit_nofile"},{"value":"auto","name":"worker_processes"}],"status_listeners":{},"client_ssl_cert_key_default":"\/usr\/local\/kong\/ssl\/kong-default.key","client_body_buffer_size":"8k","cassandra_contact_points":["127.0.0.1"],"nginx_upstream_directives":[{"value":"100","name":"keepalive_requests"},{"value":"60s","name":"keepalive_timeout"},{"value":"60","name":"keepalive"}],"admin_ssl_enabled":true,"stream_listeners":{},"nginx_proxy_real_ip_header":"X-Real-IP","proxy_access_log":"logs\/access.log","nginx_stream_directives":[{"value":"stream_prometheus_metrics 5m","name":"lua_shared_dict"}]},"version":"2.0.4","node_id":"e6e5fc6d-c4ae-41aa-8218-639c5faad58e","lua_version":"LuaJIT 2.1.0-beta3","prng_seeds":{"pid: 3271":792341169209,"pid: 3270":199173721770,"pid: 3261":219124362351},"timers":{"pending":9,"running":2},"hostname":"ip-x.y.z"}

Testing Go Plugins

How does one go about writing unit/integration tests for go plugins? Examples are in this repo but no test examples.

I know lua plugins have kong-pongo, is there a go variant?

how can i set request header?

example in go-hello only set header in response

but i want to set header berfor kong pass request to backend svc

i dig into to the kong.Request,but i only find Getxxx

please help me out

package management?

Just running make doesn't work, as it need the github.com/Kong/go-pdk module - irrespective of the path of the repository.

May be we can have a package management system? I would recommend using golang modules, but that's available only after go 1.11 . Is that's okay, I would be willing to raise a PR with go.mod and go.sum 😄

With go modules, people can place the repository anywhere and still make it work

go-pluginserver terminated: exit 0, context: ngx.timer

I ran go-hello plugin on ubuntu18.04 os，but encounter problems below:

2020/04/01 11:30:33 [notice] 18798#0: *9 [kong] go.lua:95 go-pluginserver terminated: exit 0, context: ngx.timer 2020/04/01 11:30:33 [notice] 18798#0: *9 [kong] go.lua:84 Starting go-pluginserver, context: ngx.timer

with the error log file keep refreshing until stop kong.
Many thanks!

Initialization code

As in Lua we have init_worker to initialize libraries needed in Access, I cannot seem to find the right place to add the initialization code for some encryption libraries ?