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hail: A service for pull-based continuous deployment based on hydra.
Point hail to a hydra job, set up your nix-daemon to pull from your hydra's cache, and hail will automatically pull the latest results from the job and activate them. See the README for more details.
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| Versions [RSS] | 0.1.0.0, 0.1.0.1, 0.1.0.2, 0.1.0.3, 0.2.0.0 |
|---|---|
| Change log | ChangeLog.md |
| Dependencies | base (>=4.9 && <4.10), bytestring (>=0.10.8 && <0.11), directory (>=1.3.0 && <1.4), filepath (>=1.4.1 && <1.5), http-client (>=0.5.6 && <0.6), lens (>=4.15.1 && <4.16), lens-aeson (>=1.0.0 && <1.1), netrc (>=0.2.0.0 && <0.3), network-uri (>=2.6.1 && <2.7), optparse-applicative (>=0.13.1 && <0.14), parsec (>=3.1.11 && <3.2), process (>=1.4.3 && <1.5), text (>=1.2.2 && <1.3), wreq (>=0.5 && <0.6) [details] |
| License | Apache-2.0 |
| Copyright | (c) 2017, Takt Inc. |
| Author | Shea Levy |
| Maintainer | shea.levy@takt.com |
| Uploaded | by shlevy at 2017-08-23T10:46:42Z |
| Category | System |
| Home page | https://github.com/TaktInc/hail |
| Distributions | NixOS:0.2.0.0 |
| Reverse Dependencies | 1 direct, 0 indirect [details] |
| Executables | hail |
| Downloads | 3605 total (19 in the last 30 days) |
| Rating | (no votes yet) [estimated by Bayesian average] |
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| Status | Docs not available [build log] Last success reported on 2017-08-23 [all 3 reports] |
Readme for hail-0.2.0.0
[back to package description]hail
A service for pull-based continuous deployment based on hydra
Usage
hail --profile PROFILE --job-uri HYDRA_JOB_URI
Optional flags:
--netrc-file NETRC_FILEThe path to a netrc file specifying credentials for the hydra HTTP access. Defaults to/etc/netrcif it exists.--poll-period PERIODThe period with which to poll the job, in minutes (default: 5)--oneshotJust update once, rather than in a loop.
hail assumes that the nix available in its PATH is set up to pull from its hydra's binary cache.
Operation
hail will regularly poll the latest successful build of the provided HYDRA_JOB_URI. When it changes, it will update /nix/var/nix/profiles/PROFILE to point to the new build and run /nix/var/nix/profiles/PROFILE/bin/activate
If there is already a path at /nix/var/nix/profiles/PROFILE when hail starts up, it will run the activate program immediately.
Step-by-step
- Create a hydra jobset with a job that creates the profile for the service in question. The profile should have a program at
bin/activatethat:- Sets up everything needed for the service to run (e.g. adding systemd/init.d services, initializing dbs if needed, etc)
- Is idempotent
- Can detect if there is a previous version of the service running and switch as atomically as possible
- Set up your nix config to pull from your hydra's binary cache.
- Run
hailon all machines that should run the latest version of that service (see Bootstrapping) - Enjoy
Bootstrapping
If there are multiple services each managed independently with hail, you probably want to have those hail instances themselves managed by a manager hail instance. See hail-systemd-bootstrap.nix for a way to achieve this on systemd-based systems.
Future work
- Error reporting in a monitorable way
- Handle the case where we don't want to update until all of a jobset succeeds
- Native haskell client to talk to the nix daemon
- Proper handling of manually-initiated rollbacks etc.
- Libraries/templates for easily deploying new services
- A good blue-greening story
- Handle service removal
- Incorporate with distro-agnostic service runner