Tag: docker

Helper module to generate JWT for LINE OAuth2 v2.1

LINE Messaging API 最近一個比較重大的變更是 access token 新版的發放方式(v2.1),同時也配合 OAuth2 。比較不同的點是它是用 JSON Web Token (JWT) 去取 access token,這樣的好處是如果今天 Provider 本身(也就是付錢的人)請開發商開發 bot ,他並不需要把 channel secret/access token 都給開發商(這通常也暗示你要把開發人員加到 bot admin 去,當然也可以不這麼做,就是麻煩了點)。

改用 JWT 的好處在於開發商只需要知道 channel ID 以及 Provider 幫他申請的一組 Assertion Signing Key (RSA 加密的),對 Provider 來說資訊的保護層級就提高了,終止合作只要把這組 Assertion Signing Key 砍掉就好,不必重新申請 channel access token 且/或 channel secret。

但相反地,開發商沒有 long-lived channel access token,新版的 OAuth2 認證方式使用 JWT 產生的 access token 最長只有 30 天的限期,期限到了之前要再生,某種程度造成程式開發上的困難(安全與方便通常不是站在同一邊的),原本的邏輯上要多加處理 token expiry 。

對於 API 變動來說,可以分為兩部份來看。其一,是 JWT 的取得;其二,是 access token 的取得。前者並沒有直接呼叫到 LINE Messaging API server ,所以在開發 SDK 的時候,可以先著重在已有 JWT 的情況下與 server 端做申請/列出/撤銷 access token 的行為。這部份也提出了 pull request (PR) 在等待官方團隊的審核。

Web interface for generating JWT

而 JWT 的生成就比較麻煩了,在看官網的介紹時發現做 JWT 沒有想像中那麼容易。(中間省略一段心路歷程)最後就是決定自己開發工具來幫助生成 JWT 。

clsung/line-oauth2-helper 名字有 “OAuth2” ,實則沒有關係,是用來生 JWT 的,但因為這生出來的 JWT 也只能讓 LINE OAuth2 v2.1+ 使用,所以才取這個名子。

執行的方式看 README 即可,若是一般 go 開發者使用,那 go get github.com/clsung/line-oauth2-helper/cmd/line_jwt 最快,若是系統沒有 go 的,可以考慮用 docker 的版本(若是都沒有的,請按上一頁離開):docker pull clsung/line-oauth2-helper:stable

用 line_jwt 執行的話,預設生出來的 JWT 需要在 30 分鐘內去 access LINE server ,而生出來的 access token 會在 30 天後過期,要細部調整的則建議就使用 docker / web 的版本。若是要接在程式碼當 API 呼叫的,也可以參考 cmd/ 下的程式自行開發。

Fix: Unit “containerd.service” has failed

When I upgraded yum packages, docker service had stopped. So I check the system status try to figure out the root cause….

After google ‘Subject: Unit “containerd.service” has failed’, we can find a related github issue. It seems to be a containerd problem than a docker problem, and here’s the fix: (the following shows the before and after)

[docker] Multi-stage builds

Consider the following scenario: you are going to rolling update your cluster, and it turns out your network bandwidth is limited for some reason and size of built docker image is not small enough. What’s worse, every instance of cluster will need to pull the docker image before start-up… Read More

CoreOS remove early-docker since 1284.0.0

It happens the docker daemon wasn’t alive when I login to the console.

After review the release document, it seems early-docker.target should be remove in all related target.

Ref: CoreOS Release 1284.0


Developing with consul on Macbook

For development use, we need to have consul running on localhost. When using a Macbook (Air), we need to specify the “-bind=” and “-client=” in order to have programs (tests) access to the consul agent in the container:  Read More

Install docker on Centos 7

Perform a yum search docker, we can see two docker available:

docker.x86_64 : Automates deployment of containerized applications
docker-io.x86_64 : Automates deployment of containerized applications

Well, at least for today, the docker.x86_64, which is mentioned in , is still 0.11. So please install the docker-io.x86_64, which is 1.0.0-1.el7.

Updated 20140829: there’s more up-to-date repo for docker.

Updated 20150111: it seems the repo is out of managed now. And official repo is upgraded to 1.3.2. Thus the official repo is recommended now.

% # just use original one
% # curl -O https://copr.fedoraproject.org/coprs/goldmann/docker-io/repo/epel-7/goldmann-docker-io-epel-7.repo
% # sudo mv goldmann-docker-io-epel-7.repo
% # yum update
% # yum install docker-io
% sudo service docker start
Redirecting to /bin/systemctl start docker.service