Docker Book: Difference between revisions
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Notes for upcoming book on Docker | Notes for upcoming book on Docker and PHP. | ||
== Installing Docker == | == Installing Docker == | ||
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* Point to instructions on Docker website, no point in duplicating these | * Point to instructions on Docker website, no point in duplicating these | ||
* Make sure you are running the latest version | * Make sure you are running the latest version | ||
* Use upstream repositories as the distribution ones are too out of date | |||
* If running Ubuntu, use LTS as the host | |||
== Hello World == | == Hello World == | ||
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== Basic PHP example == | == Basic PHP example == | ||
* <code>docker run --rm php:7.4-apache-buster | * <code>docker run --rm php:7.4-apache-buster php -v</code>, show output | ||
Dockerfile: | Dockerfile: | ||
| Line 25: | Line 26: | ||
<?php phpinfo(); | <?php phpinfo(); | ||
* <code>docker build -t phpinfo:latest .</code> | |||
* <code>docker run --rm -p 8000:80 phpinfo</code> | |||
* Visit localhost:8000 in browser | |||
* Ctrl+C terminates container and Docker will remove it automatically due to the <code>--rm</code> flag | |||
== Docker Compose == | |||
Docker Composer (<code>docker-compose</code>) is a way to configure Docker with YAML. For example, you can specify environment variables in a YAML list, instead of having to supply them all on the command line. It also makes life much easier if you want to run multiple containers together, e.g. web and database containers. | |||
If you are adding Docker to a project for the first time, you should use Docker Compose by default. | |||
== Dependencies == | |||
If you have multiple containers, it is likely that there will be dependencies between them. For example, the container hosting your web application most likely depends on the database container - until the database container has been started, the application is not 'ready'. | |||
Dependencies can be expressed with the <code>depends_on</code> attribute. | |||
[[Category:Docker]] | |||
Latest revision as of 08:55, 20 August 2021
Notes for upcoming book on Docker and PHP.
Installing Docker
- Point to instructions on Docker website, no point in duplicating these
- Make sure you are running the latest version
- Use upstream repositories as the distribution ones are too out of date
- If running Ubuntu, use LTS as the host
Hello World
docker run --rm hello-world- Include example output for checking
- Explain use of
--rmflag - without this we end up with lots of stopped but not removed images
Basic PHP example
docker run --rm php:7.4-apache-buster php -v, show output
Dockerfile:
FROM php:7.4-apache-buster COPY index.php /var/www/html/index.php
index.php:
<?php phpinfo();
docker build -t phpinfo:latest .docker run --rm -p 8000:80 phpinfo- Visit localhost:8000 in browser
- Ctrl+C terminates container and Docker will remove it automatically due to the
--rmflag
Docker Compose
Docker Composer (docker-compose) is a way to configure Docker with YAML. For example, you can specify environment variables in a YAML list, instead of having to supply them all on the command line. It also makes life much easier if you want to run multiple containers together, e.g. web and database containers.
If you are adding Docker to a project for the first time, you should use Docker Compose by default.
Dependencies
If you have multiple containers, it is likely that there will be dependencies between them. For example, the container hosting your web application most likely depends on the database container - until the database container has been started, the application is not 'ready'.
Dependencies can be expressed with the depends_on attribute.