Merge pull request #387 from jpetazzo/velny-k8s101-2018

bring NY 2018 changes to EU 2018
2026-08-18 19:47:52 +00:00 · 2018-10-30 12:32:24 +01:00
parent c5c1ccaa25 24e7cab2ca
commit 8530dc750f
12 changed files with 48 additions and 585 deletions
@@ -77,79 +77,6 @@ and displays aggregated logs.

 ---

-class: extra-details
-
-## Compose file format version
-
-*Particularly relevant if you have used Compose before...*
-
- Compose 1.6 introduced support for a new Compose file format (aka "v2")
-
- Services are no longer at the top level, but under a `services` section
-
- There has to be a `version` key at the top level, with value `"2"` (as a string, not an integer)
-
- Containers are placed on a dedicated network, making links unnecessary
-
- There are other minor differences, but upgrade is easy and straightforward
-
---
-
-## Service discovery in container-land
-
- We do not hard-code IP addresses in the code
-
- We do not hard-code FQDN in the code, either
-
- We just connect to a service name, and container-magic does the rest
-
-  (And by container-magic, we mean "a crafty, dynamic, embedded DNS server")
-
---
-
-## Example in `worker/worker.py`
-
-```python
-redis = Redis("`redis`")
-
-
-def get_random_bytes():
-    r = requests.get("http://`rng`/32")
-    return r.content
-
-
-def hash_bytes(data):
-    r = requests.post("http://`hasher`/",
-                      data=data,
-                      headers={"Content-Type": "application/octet-stream"})
-```
-
-(Full source code available [here](
-https://@@GITREPO@@/blob/8279a3bce9398f7c1a53bdd95187c53eda4e6435/dockercoins/worker/worker.py#L17
-))
-
---
-
-class: extra-details
-
-## Links, naming, and service discovery
-
- Containers can have network aliases (resolvable through DNS)
-
- Compose file version 2+ makes each container reachable through its service name
-
- Compose file version 1 did require "links" sections
-
- Network aliases are automatically namespaced
-
-  - you can have multiple apps declaring and using a service named `database`
-
-  - containers in the blue app will resolve `database` to the IP of the blue database
-
-  - containers in the green app will resolve `database` to the IP of the green database
-
---
-
 ## What's this application?

 --
@@ -240,50 +167,6 @@ Stop the app with `^C`, edit `dockercoins.yml`, comment out the `volumes` sectio

 ---

-class: extra-details
-
-## Why does the speed seem irregular?
-
- It *looks like* the speed is approximately 4 hashes/second
-
- Or more precisely: 4 hashes/second, with regular dips down to zero
-
- Why?
-
--
-
-class: extra-details
-
- The app actually has a constant, steady speed: 3.33 hashes/second
-  <br/>
-  (which corresponds to 1 hash every 0.3 seconds, for *reasons*)
-
- Yes, and?
-
---
-
-class: extra-details
-
-## The reason why this graph is *not awesome*
-
- The worker doesn't update the counter after every loop, but up to once per second
-
- The speed is computed by the browser, checking the counter about once per second
-
- Between two consecutive updates, the counter will increase either by 4, or by 0
-
- The perceived speed will therefore be 4 - 4 - 4 - 0 - 4 - 4 - 0 etc.
-
- What can we conclude from this?
-
--
-
-class: extra-details
-
- "I'm clearly incapable of writing good frontend code!" 😀 — Jérôme
-
---
-
 ## Stopping the application

 - If we interrupt Compose (with `^C`), it will politely ask the Docker Engine to stop the app