py-cookiecutter-templates/docker-compose/{{ cookiecutter.__project_slug }}/README.md

# {{ cookiecutter.__service_slug.capitalize() }} Docker Compose files

Docker Compose files to spin up an instance of {{ cookiecutter.__service_slug.capitalize() }}.

# How to run

Add a `COMPOSE_ENV` file and save its location as a shell variable along with the location where this repo lives, here for example `/opt/containers/{{ cookiecutter.__project_slug }}` plus all other variables. At [env/fqdn_context.env.example](env/fqdn_context.env.example) you'll find an example environment file.

When everything's ready start {{ cookiecutter.__service_slug.capitalize() }} with Docker Compose, otherwise head down to [Initial setup](#initial-setup) first.

## Environment
```
export COMPOSE_DIR='/opt/containers/{{ cookiecutter.__project_slug }}'
export COMPOSE_CTX='ux_vilnius'
export COMPOSE_PROJECT='{{ cookiecutter.__service_slug }}-'"${COMPOSE_CTX}"
export COMPOSE_FILE="${COMPOSE_DIR}"'/docker-compose.yml'{% if cookiecutter.build == "yes" %}
export COMPOSE_OVERRIDE="${COMPOSE_DIR%/}"'/docker-compose.override.yml'{% endif %}
export COMPOSE_ENV=<add accordingly>
```

## Context

On your deployment machine create the necessary Docker context to connect to and control the Docker daemon on whatever target host you'll be using, for example:
```
docker context create fully.qualified.domain.name --docker 'host=ssh://root@fully.qualified.domain.name'
```

{%- if cookiecutter.build == "yes" %}

## Build

{%- set components = cookiecutter.__component_list_slug.split(',') -%}
{% for component in components %}
{%- if loop.first %}
We build the `{{ cookiecutter.__service_slug }}` image locally. Our adjustment to the official image is simply adding `/tmp/{{ cookiecutter.__service_slug }}` to it. See [build-context/{{ cookiecutter.__service_slug }}/Dockerfile](build-context/{{ cookiecutter.__service_slug }}/Dockerfile). We use `/tmp/{{ cookiecutter.__service_slug }}` to bind-mount a dedicated ZFS dataset for the application's `tmpdir` location.
{%- endif %}
{%- endfor %}

```
docker compose --project-name "${COMPOSE_PROJECT}" --file "${COMPOSE_FILE}" --file "${COMPOSE_OVERRIDE}" --env-file "${COMPOSE_ENV}" --profile 'build' build
```
{%- endif %}

## Start

```
{%- if ',' in cookiecutter.__component_list_slug %}
docker --context 'fully.qualified.domain.name' compose --project-name "${COMPOSE_PROJECT}" --file "${COMPOSE_FILE}" --env-file "${COMPOSE_ENV}" --profile 'full' up --detach
{%- else %}
docker --context 'fully.qualified.domain.name' compose --project-name "${COMPOSE_PROJECT}" --file "${COMPOSE_FILE}" --env-file "${COMPOSE_ENV}" up --detach
{%- endif %}
```

# Initial setup

We're assuming you run Docker Compose workloads with ZFS-based bind mounts. ZFS management, creating a zpool and setting adequate properties for its datasets is out of scope of this document.

## Datasets

Create ZFS datasets and set permissions as needed.

* Parent dateset
    ```
    zfs create -o mountpoint=/opt/docker-data 'zpool/docker-data'
    ```

* Container-specific datasets
    ```
{%- if ',' in cookiecutter.__component_list_slug -%}
{%- set components = cookiecutter.__component_list_slug.split(',') -%}
{%- for component in components %}
    zfs create -p 'zpool/docker-data/{{ cookiecutter.__service_slug }}-'"${COMPOSE_CTX}"'/{{ component }}/data/db'
    zfs create -p 'zpool/docker-data/{{ cookiecutter.__service_slug }}-'"${COMPOSE_CTX}"'/{{ component }}/data/logs'
    zfs create -p 'zpool/docker-data/{{ cookiecutter.__service_slug }}-'"${COMPOSE_CTX}"'/{{ component }}/config'
{%- endfor -%}
{%- else %}
    zfs create -p 'zpool/docker-data/{{ cookiecutter.__service_slug }}-'"${COMPOSE_CTX}"'/{{ cookiecutter.__service_slug }}/data/db'
    zfs create -p 'zpool/docker-data/{{ cookiecutter.__service_slug }}-'"${COMPOSE_CTX}"'/{{ cookiecutter.__service_slug }}/data/logs'
    zfs create -p 'zpool/docker-data/{{ cookiecutter.__service_slug }}-'"${COMPOSE_CTX}"'/{{ cookiecutter.__service_slug }}/config'
{%- endif %}
    ```
    When changing bind mount locations to real ones remember to also update `volumes:` in [docker-compose.yml](docker-compose.yml).

* Create subdirs
    ```
{%- set components = cookiecutter.__component_list_slug.split(',') -%}
{% for component in components %}
{%- if loop.first %}
    mkdir -p '/opt/docker-data/{{ cookiecutter.__service_slug }}-'"${COMPOSE_CTX}"'/{{ cookiecutter.__service_slug }}/'{'.ssh','config','data','projects'}
{%- endif %}
{%- endfor %}
    ```

* Change ownership
    ```
{%- set components = cookiecutter.__component_list_slug.split(',') -%}
{% for component in components %}
{%- if loop.first %}
    chown -R 1000:1000 '/opt/docker-data/{{ cookiecutter.__service_slug }}-${COMPOSE_CTX}/{{ cookiecutter.__service_slug }}/data/'{*,.*}
{%- endif %}
{%- endfor %}
    ```

## Additional files

Place the following files on target server. Use the directory structure at [build-context](build-context) as a guide, specifically at `docker-data`.

```
build-context/
{%- if ',' in cookiecutter.__component_list_slug -%}
{%- set components = cookiecutter.__component_list_slug.split(',') -%}
{%- for component in components %}
{%- if not loop.last %}
├── {{ component }}
│   ├── docker-data
│   |   └── config
│   │       └── {{ component }}.cfg
│   ├── Dockerfile
│   └── extras
{%- else %}
└── {{ component }}
    ├── docker-data
    |   └── config
    │       └── {{ component }}.cfg
    ├── Dockerfile
    └── extras
{%- endif %}
{%- endfor %}
{%- else %}
├── docker-data
│   └── config
│       └── {{ cookiecutter.__service_slug }}.cfg
├── Dockerfile
└── extras
{%- endif %}
```

When done head back up to [How to run](#how-to-run).