April 2024
Intermediate to advanced
368 pages
9h 54m
Japanese
Content preview from つくって、壊して、直して学ぶ Kubernetes入門
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
171
Chapter
6
Part
2
Kubernetes
Kubernetes
6
.
4
Pod
の外部から情報を読み込む
ConfigMap
環境変数など、コンテナの外部から値を設定したいときに利用するリソースです。例えば、環
境ごとに異なるデータベース名、ユーザー名などを変更する可能性があるすべての設定情報に使
えます。
ConfigMap
を利用する方法は
3
つあります。
1
.
コンテナ内のコマンドの引数として読み込む
2
.
コンテナの環境変数として読み込む
3
.
ボリュームを利用してアプリケーションのファイルとして読み込む
今回はよく利用する
2
.
と
3
.
の方法を説明していきます。
1
.
に関して詳細を知りたい場合はド
キュメント
※
2
をご参照ください。
6.4.1
コンテナの環境変数として読み込む
環境変数を利用してアプリケーションに設定値を渡す方法です。アプリケーションの実装で環
境変数を受け取れるようになっていれば、この方法で簡単に外部から設定値を利用可能です。
今回はポート番号を外部から指定できるように
hello-server
の実装を変更しました（タ
グ
:
1
.
4
）。
Kubernetes
マニフェストを利用してポート番号を変更してみましょう。マニフェス
トは次のようになります。
※
2
https://kubernetes.io/docs/concepts/configuration/configmap/#configmaps-and-pods
Chapter
6
Part
2
Kubernetes
Kubernetes
172
YAML
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.