Small Docker Notes - Revision history

Admin at 12:54, 26 December 2019

2019-12-26T12:54:48Z

Admin at 12:41, 28 April 2016

2016-04-28T12:41:27Z

Admin at 10:11, 28 April 2016

2016-04-28T10:11:02Z

Admin: Created page with "Note - ''vm'' and ''container'' is used below interchangeably. == Installation and Verification ==

  # install Docker $ curl -fsSL https://get.docker.com/ | sh    # add..."

2016-04-28T10:09:57Z

Created page with "Note - ''vm'' and ''container'' is used below interchangeably. == Installation and Verification == <pre> # install Docker $ curl -fsSL https://get.docker.com/ | sh # add..."

New page

Note - ''vm'' and ''container'' is used below interchangeably.

== Installation and Verification ==

<pre> # install Docker
$ curl -fsSL https://get.docker.com/ | sh

# add your-user to docker group to be able to run docker as non-root
$ usermod -aG docker your-user
# you'll need to log out and in after this, or run all docker commands as root

# verify the installation
$ docker run hello-world
# this should download image from docker hub, and print "Hello from Docker." message</pre>

== Stack in Separate Containers ==

Let's create few containers to hold different parts of the stack:
* nginx
* php-fpm
* mysql
* data volume for mysql
* kyoto tycoon with python
* data volume for kyoto tycoon

First, create config file for docker compose, called ''docker-compose.yml'' .

# enter the following; this pulls latest nginx image,
# and binds 8080 port on your machine to 80 port in the container
<pre>nginx:
# based on latest nginx image
image: nginx:latest
ports:
# map vm's port 80 to local port 8080
- 8080:80</pre>

Now we have defined our first image, let's get it running:
<pre>$ docker-compose up -d

# you should be able to reach the nginx on localhost:8080 now;
# you can always check running containers, incl. ports map, with
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
e795e45c3e6b nginx:latest "nginx -g 'daemon off" 24 hours ago Up 24 hours 443/tcp, 0.0.0.0:8080->80/tcp dockertut_nginx_1

# using container ID or name from `docker ps`, you can get lots of useful info with
$ docker inspect {container-id|name}
</pre>

=== Adding php-fpm ===

Let's now add VM for php-fpm, and edit the ''docker-compose.yml'' like this:
<pre>nginx:
build:
# don't use image, build based on ./docker/nginx/Dockerfile
./docker/nginx/
ports:
# vm's port 80 will be available as 8080 on localhost
- 8080:80
links:
# has access to 'php' vm
- php
volumes:
# mount current directory as /var/www/html inside the container
- .:/var/www/html

php:
image: php:5.5-fpm
expose:
# expose port 9000 only to other vm's, not host machine like the 'ports' command
- 9000
volumes:
- .:/var/www/html</pre>

Now the nginx image is based on ''Dockerfile'' in ''./docker/nginx/'' folder, which should look like this:

<pre>FROM nginx:latest
COPY ./default.conf /etc/nginx/conf.d/default.conf</pre>

This will build vm from ''nginx:latest'' image, and copy ''./docker/nginx/default.conf'' to ''/etc/nginx/conf.d/'' in the vm. Create this file with the following content:
<pre>server {
listen 80 default_server;
root /var/www/html;
index index.html index.php;

charset utf-8;

location / {
try_files $uri $uri/ /index.php?$query_string;
}

location = /favicon.ico { access_log off; log_not_found off; }
location = /robots.txt { access_log off; log_not_found off; }

access_log off;
error_log /var/log/nginx/error.log error;

sendfile off;

client_max_body_size 100m;

location ~ \.php$ {
fastcgi_split_path_info ^(.+\.php)(/.+)$;
fastcgi_pass php:9000;
fastcgi_index index.php;
include fastcgi_params;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_intercept_errors off;
fastcgi_buffer_size 16k;
fastcgi_buffers 4 16k;
}

location ~ /\.ht {
deny all;
}
}</pre>

Note that <tt>root /var/www/html;</tt> will actually use the mount of our local directory.

Also note <tt>fastcgi_pass php:9000;</tt> that uses the link created using ''links:'' key in the ''docker-compose.yml''.

Now, let's just add ''index.php'' in the root folder (where ''docker-compose.yml'' resides):

<pre><!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Hello World!</title>
</head>
<body>
<?php echo "this is php!"; ?>
</body>
</html></pre>

Let's start the images; this time, php image should be pulled as well:
<pre>$ docker-compose up -d
Pulling php (php:5.5-fpm)...
5.5-fpm: Pulling from library/php
efd26ecc9548: Already exists <-- the nginx image, already pulled
a3ed95caeb02: Download complete
...</pre>

If you get "''Service 'nginx' needs to be built, but --no-build was passed.''" message, run <tt>`docker-compose build`</tt> and <tt>`docker-compose up -d`</tt>. Verify all is OK and started:
<pre>docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
fd04b796e34f dockertut_nginx "nginx -g 'daemon off" 4 seconds ago Up 4 seconds 443/tcp, 0.0.0.0:8080->80/tcp dockertut_nginx_1
402fb35b762e php:5.5-fpm "php-fpm" 5 seconds ago Up 4 seconds 9000/tcp dockertut_php_1</pre>

Note that nginx's image name has changed, since we have built a new one.

Now, when you open ''localhost:8080'', you should get "this is php!" message. Open the ''index.php'' file, and edit it; the change should be immediately reflected. Sweet!

=== Data Volumes ===

Both the ''nginx'' and ''php'' vm's now use local folder through the ''volumes'' directive.

Better yet is to have a separate container; we'll build this container based on some image we're already using (to avoid having yet another image downloaded), but it won't be running - it'll just sit there, collecting data. Change ''docker-compose.yml'' like this:

<pre>nginx:
build:
./docker/nginx/
ports:
- 8080:80
links:
- php
volumes_from:
- app

php:
image: php:5.5-fpm
expose:
- 9000
volumes_from:
- app

app:
# it's good practice to "reuse" some image, not to have yet another one pulled
image: php:5.5-fpm
volumes:
- .:/var/www/html
# container won't run - it'll execute `true` and sit there, collecting data
command: "true"</pre>

Let's check all is OK:

<pre>$ docker-compose up -d
Creating dockertut_app_1...
Recreating dockertut_php_1...
Recreating dockertut_nginx_1...

# list all containers (note that 'app' container is not listed in `ps`, since it's not running):
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
af0110364abf dockertut_nginx "nginx -g 'daemon off" 2 minutes ago Up 2 minutes 443/tcp, 0.0.0.0:8080->80/tcp dockertut_nginx_1
94a1c3d317dd php:5.5-fpm "php-fpm" 2 minutes ago Up 2 minutes 9000/tcp dockertut_php_1
861cca283ceb php:5.5-fpm "true" 2 minutes ago Exited (0) 2 minutes ago dockertut_app_1</pre>

and check that ''localhost:8080'' is still responding.

TBC

← Older revision		Revision as of 12:54, 26 December 2019
Line 277:		Line 277:
	mysql> _</pre>		mysql> _</pre>
	Neat, huh? The ''-i'' means to run interactive command, ''-t'' to run in terminal.		Neat, huh? The ''-i'' means to run interactive command, ''-t'' to run in terminal.
		+
		+	== Manage Docker as non-root User ==
		+
		+	By creating <tt>docker</tt> group, and adding users to it, you may select users that can manage docker daemon and processes:
		+
		+	<pre>$ sudo groupadd docker
		+	$ sudo usermod -aG docker $USER</pre>
		+
		+	Afterwards, restart your machine (or, log out and in, and stop and start the docker daemon), and you should be able to control docker without the need for <tt>sudo</tt>.

@@ Line 13: / Line 13: @@
 $ docker run hello-world
    # this should download image from docker hub, and print "Hello from Docker." message</pre>
 == Stack in Separate Containers ==
@@ Line 74: / Line 81: @@
 <pre>FROM nginx:latest
 COPY ./default.conf /etc/nginx/conf.d/default.conf</pre>
 This will build vm from ''nginx:latest'' image, and copy ''./docker/nginx/default.conf'' to ''/etc/nginx/conf.d/'' in the vm. Create this file with the following content:
@@ Line 138: / Line 147: @@
 ...</pre>
-If you get "''Service 'nginx' needs to be built, but --no-build was passed.''" message, run <tt>`docker-compose build`</tt> and <tt>`docker-compose up -d`</tt>. Verify all is OK and started:
+If you get "''Service 'nginx' needs to be built, but --no-build was passed.''" message, run <tt>`docker-compose build`</tt> and again <tt>`docker-compose up -d`</tt>. Verify all is OK and started:
-<pre>docker ps
+<pre>$ docker ps
 CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                           NAMES
 fd04b796e34f        dockertut_nginx     "nginx -g 'daemon off"   4 seconds ago       Up 4 seconds        443/tcp, 0.0.0.0:8080->80/tcp   dockertut_nginx_1
@@ Line 195: / Line 204: @@
 and check that ''localhost:8080'' is still responding.
-TBC
+=== Adding MySQL ===

@@ Line 25: / Line 25: @@
 First, create config file for docker compose, called ''docker-compose.yml'' .
 <pre>nginx:
      # based on latest nginx image