Comments on course

jmanton

• On this page at the bottom it says istioctl x uninstall --purge. The 'x' is a typo. It should say (I think) istioctl uninstall --purge.

I will add comments to this post if I see any other typos or have comments on wording.

jmanton

On this page the last line in the yaml of the VirtualService specification is incorrectly indented. It says:

            port:
            number: 80

It should say:

            port:
              number: 80

jmanton

On this page at the bottom there is the text:

If we deployed the customers service version v2, the responses we would get back when calling the ht‌tp://customers.default.svc.cluster.local would be random. They would either come from the v2 or v1 version of the customers service. That is because the selector label in the Kubernetes service does not have the version label set.

The customers service version v2 service is deployed 2 pages later in the lab. So at this point this paragraph is confusing and doesn't really make sense. It should be moved to a page after the customers VirtualService has been modified to split traffic between the versions, perhaps on this page.

jmanton

I made another comment here about a hidden character. It said it had to be approved. When will that be done? Will I have to have more of my comments approved?

jmanton

On this page, in the yaml for the web-frontend, the value for the environment variable CUSTOMER_SERVICE_URL has an unprintable character.

To see this you can copy the URL string from the web page for that variable into a file on linux and examine with and without non-printing characters:

cat > testfile
value: 'ht‌tp://customers.default.svc.cluster.local'
ctrl-d

cat testfile
value: 'ht‌tp://customers.default.svc.cluster.local'

cat -v testfile
value: 'htM-bM-^@M-^Ltp://customers.default.svc.cluster.local'

If the unprintable section is not removed, the following error will show up when trying to access the page in the subsequent step:

Error calling downstream service
ERR_UNESCAPED_CHARACTERS
TypeError [ERR_UNESCAPED_CHARACTERS]: Request path contains unescaped characters
    at new ClientRequest (node:_http_client:184:13)
    at Object.request (node:http:102:10)
    at RedirectableRequest._performRequest (/app/node_modules/follow-redirects/index.js:279:24)
    at new RedirectableRequest (/app/node_modules/follow-redirects/index.js:61:8)
    at Object.request (/app/node_modules/follow-redirects/index.js:511:14)
    at dispatchHttpRequest (/app/node_modules/axios/lib/adapters/http.js:262:25)
    at new Promise (<anonymous>)
    at httpAdapter (/app/node_modules/axios/lib/adapters/http.js:49:10)
    at dispatchRequest (/app/node_modules/axios/lib/core/dispatchRequest.js:58:10)
    at Axios.request (/app/node_modules/axios/lib/core/Axios.js:109:15)

jmanton

@jmanton said:
I made another comment here about a hidden character. It said it had to be approved. When will that be done? Will I have to have more of my comments approved?

Ok, it got approved 1 minute after I posted this. Thanks

jmanton

As a side note, it may be that some of these errors would not be there if I downloaded the github repository. However, for me (and I assume at least some others) copying and pasting from the web page as I move through the course helps to keep me more engaged with the material. So the typos and hidden characters on the web pages for .yaml files make a difference for people that learn like I do.

fcioanca

Hi @jmanton

Thank you for flagging possible typos in the course. They will be addressed and fixed in collaboration with the course maintainer; some may be fixed faster than others.

Regarding the hidden characters you flagged, the html code used to format the text on the page does not show any characters. Unfortunately, we are not able to fix anything there to improve your experience. You can either use the files from the shared GitHub repo, or if you copy and paste from the course, you may want to use a simple text editor to paste the code first - this should help with the hidden characters.

I hope this helps!
Best regards,
Flavia
Linux Foundation Training Team

jmanton

On this page the same http field as in the above comment also has the hidden character embedded.
So on the above page, in the pod template for the web-frontend deployment has a hidden character in the value of the environment variable CUSTOMER_SERVICE_URL.

jmanton

The same page also has the indent problem in the web-frontend VirtualService. The "number: 80" line should be indented an additional 2 spaces.

jmanton

I was just blocked by CloudFlare, but apparently unblocked. I'm going to stop providing feedback, because apparently if the wrong character strings are in the posts I get an IP ban from CloudFlare.

This is not a good way to encourage feedback about problems in the course.

jmanton

@fcioanca said:
Hi @jmanton

Thank you for flagging possible typos in the course. They will be addressed and fixed in collaboration with the course maintainer; some may be fixed faster than others.

Regarding the hidden characters you flagged, the html code used to format the text on the page does not show any characters. Unfortunately, we are not able to fix anything there to improve your experience. You can either use the files from the shared GitHub repo, or if you copy and paste from the course, you may want to use a simple text editor to paste the code first - this should help with the hidden characters.

I hope this helps!
Best regards,
Flavia
Linux Foundation Training Team

The hidden character is just that. It is hidden. You have to look at it using an editor that prints hidden characters. However it happily copies and pastes into files, but when those files are used they will throw an error.

one000mph

On lab 4.2 it is unclear which namespace is being used to apply and read resources. Although I was able to figure this out, adding the namespace to the commands would be helpful to avoid errors

kubectl apply -n istio-system -f samples/addons/prometheus.yaml

With Prometheus now running and collecting metrics, send another request to the productpage service:

SLEEP_POD=$(kubectl get pod -n default -l app=sleep -ojsonpath='{.items[0].metadata.name}')

kubectl exec -n default $SLEEP_POD -it -- curl productpage:9080/productpage | head