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https://github.com/willfarrell/docker-crontab
A docker job scheduler (aka. crontab for docker)
https://github.com/willfarrell/docker-crontab
crontab docker
Last synced: 3 months ago
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A docker job scheduler (aka. crontab for docker)
- Host: GitHub
- URL: https://github.com/willfarrell/docker-crontab
- Owner: willfarrell
- License: mit
- Created: 2017-02-12T23:10:48.000Z (over 7 years ago)
- Default Branch: main
- Last Pushed: 2023-09-12T15:27:58.000Z (about 1 year ago)
- Last Synced: 2024-06-28T06:41:42.131Z (4 months ago)
- Topics: crontab, docker
- Language: Shell
- Size: 95.7 KB
- Stars: 294
- Watchers: 8
- Forks: 63
- Open Issues: 27
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
README
# docker-crontab
A simple wrapper over `docker` to all complex cron job to be run in other containers.
## Supported tags and Dockerfile links
- [`latest` (*Dockerfile*)](https://github.com/willfarrell/docker-crontab/blob/master/Dockerfile)
- [`1.0.0` (*Dockerfile*)](https://github.com/willfarrell/docker-crontab/blob/1.0.0/Dockerfile)
- [`0.6.0` (*Dockerfile*)](https://github.com/willfarrell/docker-crontab/blob/0.6.0/Dockerfile)
 [](http://microbadger.com/images/willfarrell/crontab "Get your own image badge on microbadger.com")
## Why?
Yes, I'm aware of [mcuadros/ofelia](https://github.com/mcuadros/ofelia) (>250MB when this was created), it was the main inspiration for this project.
A great project, don't get me wrong. It was just missing certain key enterprise features I felt were required to support where docker is heading.
## Features
- Easy to read schedule syntax allowed.
- Allows for comments, cause we all need friendly reminders of what `update_script.sh` actually does.
- Start an image using `image`.
- Run command in a container using `container`.
- Run command on a instances of a scaled container using `project`.
- Ability to trigger scripts in other containers on completion cron job using `trigger`.
## Config file
The config file can be specifed in any of `json`, `toml`, or `yaml`, and can be defined as either an array or mapping (top-level keys will be ignored; can be useful for organizing commands)
- `name`: Human readable name that will be used as the job filename. Will be converted into a slug. Optional.
- `comment`: Comments to be included with crontab entry. Optional.
- `schedule`: Crontab schedule syntax as described in https://en.wikipedia.org/wiki/Cron. Ex `@hourly`, `@every 1h30m`, `* * * * *`. Required.
- `command`: Command to be run on in crontab container or docker container/image. Required.
- `image`: Docker images name (ex `library/alpine:3.5`). Optional.
- `project`: Docker Compose/Swarm project name. Optional, only applies when `contain` is included.
- `container`: Full container name or container alias if `project` is set. Ignored if `image` is included. Optional.
- `dockerargs`: Command line docker `run`/`exec` arguments for full control. Defaults to ` `.
- `trigger`: Array of docker-crontab subset objects. Subset includes: `image`,`project`,`container`,`command`,`dockerargs`
- `onstart`: Run the command on `crontab` container start, set to `true`. Optional, defaults to falsey.
See [`config-samples`](config-samples) for examples.
```json
[{
"schedule":"@every 5m",
"command":"/usr/sbin/logrotate /etc/logrotate.conf"
},{
"comment":"Regenerate Certificate then reload nginx",
"schedule":"43 6,18 * * *",
"command":"sh -c 'dehydrated --cron --out /etc/ssl --domain ${LE_DOMAIN} --challenge dns-01 --hook dehydrated-dns'",
"dockerargs":"--env-file /opt/crontab/env/letsencrypt.env -v webapp_nginx_tls_cert:/etc/ssl -v webapp_nginx_acme_challenge:/var/www/.well-known/acme-challenge",
"image":"willfarrell/letsencrypt",
"trigger":[{
"command":"sh -c '/etc/scripts/make_hpkp ${NGINX_DOMAIN} && /usr/sbin/nginx -t && /usr/sbin/nginx -s reload'",
"project":"conduit",
"container":"nginx"
}],
"onstart":true
}]
```
## How to use
### Command Line
```bash
docker build -t crontab .
docker run -d \
-v /var/run/docker.sock:/var/run/docker.sock:ro \
-v ./env:/opt/env:ro \
-v /path/to/config/dir:/opt/crontab:rw \
-v /path/to/logs:/var/log/crontab:rw \
crontab
```
### Use with docker-compose
1. Figure out which network name used for your docker-compose containers
* use `docker network ls` to see existing networks
* if your `docker-compose.yml` is in `my_dir` directory, you probably has network `my_dir_default`
* otherwise [read the docker-compose docs](https://docs.docker.com/compose/networking/)
2. Add `dockerargs` to your docker-crontab `config.json`
* use `--network NETWORK_NAME` to connect new container into docker-compose network
* use `--rm --name NAME` to use named container
* e.g. `"dockerargs": "--network my_dir_default --rm --name my-best-cron-job"`
### Dockerfile
```Dockerfile
FROM willfarrell/crontab
COPY config.json ${HOME_DIR}/
```
### Logrotate Dockerfile
```Dockerfile
FROM willfarrell/crontab
RUN apk add --no-cache logrotate
RUN echo "*/5 * * * * /usr/sbin/logrotate /etc/logrotate.conf" >> /etc/crontabs/logrotate
COPY logrotate.conf /etc/logrotate.conf
CMD ["crond", "-f"]
```
### Logging - In Dev
All `stdout` is captured, formatted, and saved to `/var/log/crontab/jobs.log`. Set `LOG_FILE` to `/dev/null` to disable logging.
example: `e6ced859-1563-493b-b1b1-5a190b29e938 2017-06-18T01:27:10+0000 [info] Start Cronjob **map-a-vol** map a volume`
grok: `CRONTABLOG %{DATA:request_id} %{TIMESTAMP_ISO8601:timestamp} \[%{LOGLEVEL:severity}\] %{GREEDYDATA:message}`
## TODO
- [ ] Have ability to auto regenerate crontab on file change (signal HUP?)
- [ ] Run commands on host machine (w/ --privileged?)
- [ ] Write tests
- [ ] Setup TravisCI