Technosoft2000 Alpine Base image

An Alpine Base image for all related images provided by Technosoft2000

For easier creation and maintenance of docker images I've created an own base image which is based on the original Alpine Image but with the following container startup lifecyle:

Updates

2020-10-05 - 3.12-1

• updated to Alpine 3.12.0
• updated gosu to 1.12

For previous changes see at full changelog.

Features

• well defined container startup lifecyle, but still conform with the docker idea to run only one application
• no usage of a supervisor - be simple, be clean
• support for release ASCII graphics and information which is shown at startup
• integrated logging functions TODO

Usage

Create the container:

docker create --name=<container name> --restart=always \
[-v <host folder>:<container folder> \
[-e APP_REPO=https://github.com/<insert here the app repo>.git \]
[-e APP_BRANCH=master \]
[-e SET_CONTAINER_TIMEZONE=true \]
[-e CONTAINER_TIMEZONE=<container timezone value> \]
[-e PGID=<group ID (gid)> -e PUID=<user ID (uid)> \]
-p <external port>:<internal port> \
<image name>

Example for the technosoft2000/calibre-web image:

docker create --name=calibre-web --restart=always \
-v /volume1/books:/books \
-v /etc/localtime:/etc/localtime:ro \
-e PGID=65539 -e PUID=1029 \
-p 8083:8083 \
technosoft2000/calibre-web

or

docker create --name=calibre-web --restart=always \
-v /volume1/books:/books \
-e SET_CONTAINER_TIMEZONE=true \
-e CONTAINER_TIMEZONE=Europe/Vienna \
-e PGID=65539 -e PUID=1029 \
-p 8083:8083 \
technosoft2000/calibre-web

Start the container:

docker start <container name>

Parameters

Introduction

The parameters are split into two parts which are separated via colon. The left side describes the host and the right side the container. For example a port definition looks like this -p external:internal and defines the port mapping from internal (the container) to external (the host). So -p 8080:80 would expose port 80 from inside the container to be accessible from the host's IP on port 8080. Accessing http://'host':8080 (e.g. http://192.168.0.10:8080) would then show you what's running INSIDE the container on port 80.

Details

• -v /etc/localhost - for timesync - optional
• -e APP_REPO - set it to the application GitHub repository
• -e APP_BRANCH - set which application GitHub repository branch you want to use, master (default branch) - optional
• -e SET_CONTAINER_TIMEZONE - set it to true if the specified CONTAINER_TIMEZONE should be used - optional
• -e CONTAINER_TIMEZONE - container timezone as found under the directory /usr/share/zoneinfo/ - optional
• -e PGID for GroupID - see below for explanation - optional
• -e PUID for UserID - see below for explanation - optional

Container Timezone

In the case of the Synology NAS it is not possible to map /etc/localtime for timesync, and for this and similar case set SET_CONTAINER_TIMEZONE to true and specify with CONTAINER_TIMEZONE which timezone should be used. The possible container timezones can be found under the directory /usr/share/zoneinfo/.

Examples:

• UTC - this is the default value if no value is set
• Europe/Berlin
• Europe/Vienna
• America/New_York
• ...

Once the container is running you can get all possible timezones as tree via the command docker exec -it <CONTAINER> tree /usr/share/zoneinfo

See also at possible timezone values.

Don't use the value localtime because it results into: failed to access '/etc/localtime': Too many levels of symbolic links

User / Group Identifiers

Sometimes when using data volumes (-v flags) permissions issues can arise between the host OS and the container. We avoid this issue by allowing you to specify the user PUID and group PGID. Ensure the data volume directory on the host is owned by the same user you specify and it will "just work" ™.

In this instance PUID=1001 and PGID=1001. To find yours use id user as below:

  $ id <dockeruser>
    uid=1001(dockeruser) gid=1001(dockergroup) groups=1001(dockergroup)

Additional

Shell access whilst the container is running: docker exec -it <CONTAINER> /bin/bash

Upgrade to the latest version of the application which runs in the container: docker restart <CONTAINER>

To monitor the logs of the container in realtime: docker logs -f <CONTAINER>

Show used base image version number of the container: docker inspect -f '{{ index .Config.Labels "image.base.version" }}' <CONTAINER>