With bash on Windows 10, why does it execute my $() as separate commands? - mysql

Question

I'm learning how to work with Docker and Minikube on a Windows 10 Home computer. I've installed the needed software OK. I've installed Docker, minikube, kubectl, and a recent version of MySQL, properly pathed so its CLI can be used. I'm using either the Bash console provided by GIT, and/or the Bash console provided by Cygwin. Both seem to provide the same (bad) results.
I start Docker, and install the MySQL service. The kubectl get all shows everything running OK.
Per the programming book I'm working through, I want to try accessing MySQL through this command:
mysql -h $(minikube service mysql-svc --format "{{.IP}}") -P $(minikube service mysql-svc --format "{{.Port}}") -u root -p
The result should be the MySQL CLI prompt, like mysql> . Instead I get this behavior:
A popup window stating "Windows cannot find '192.168.99.101'. Make sure you typed the name correctly, and then try again."
The console text:
The system cannot find the file 192.168.99.101.
*
X open url failed: 192.168.99.101: exit status 1
*
* minikube is exiting due to an error. If the above message is not useful, open an issue:
- (URL for sending an error message)
A popup window stating "Windows cannot find '31067'. Make sure you typed the name correctly, and then try again."
The console text:
mysql: [ERROR] Unknown suffix '|' used for variable 'port' (value (gives the border fence that surrounds the output from minikube service mysql-svc .)
mysql: [ERROR] (path to mysql.exe): Error while setting value '|-----|--- (etc)' to 'port'
The expected behavior is to insert an IP and Port into the mysql command line, then firing a command like mysql -h http://192.168.99.101 -P 31067 -u root -p .
I think that the problem is with the using the Bash console in a Windows environment. Any explanation is appreciated.
Thanks,
Jerome.
UPDATE ON 8/7/2020:
I'm asked to more thoroughly document my issue. Here we go.
Here is what Docker knows:
$ docker images
REPOSITORY TAG
IMAGE ID CREATED SIZE
logicaltiger/cloudnative-statelessness-posts latest
3a3c66daf7f3 5 days ago 139MB
logicaltiger/cloudnative-statelessness-connections latest
d060e9857f49 5 days ago 139MB
logicaltiger/cloudnative-statelessness-connectionposts-stateful latest
ce33f0966380 5 days ago 123MB
openjdk 8-jdk-alpine
a3562aa0b991 15 months ago 105MB
mysql 8.0.12
ee1e8adfcefb 22 months ago 484MB
Here is my reconfiguring of minikube. Other posters suggested that minikube runs iffy unless given a lot of resources.
$ minikube delete
* Deleting "minikube" in virtualbox ...
* Removed all traces of the "minikube" cluster.
$ minikube start --cpus=4 --memory=4096
* minikube v1.12.1 on Microsoft Windows 10 Home 10.0.18363 Build 18363
* Automatically selected the virtualbox driver
* Starting control plane node minikube in cluster minikube
* Creating virtualbox VM (CPUs=4, Memory=4096MB, Disk=20000MB) ...
* Found network options:
- NO_PROXY=192.168.99.100
- no_proxy=192.168.99.100
* Preparing Kubernetes v1.18.3 on Docker 19.03.12 ...
- env NO_PROXY=192.168.99.100
* Verifying Kubernetes components...
* Enabled addons: default-storageclass, storage-provisioner
* Done! kubectl is now configured to use "minikube"
After starting mysql from its yaml file I have it running:
$ kubectl get all
NAME READY STATUS RESTARTS AGE
pod/mysql-7dbfd4dbc4-b2tmm 1/1 Running 0 2m55s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) A
GE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 6
m43s
service/mysql-svc NodePort 10.102.7.119 <none> 3306:32235/TCP 2
m55s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/mysql 1/1 1 1 2m55s
NAME DESIRED CURRENT READY AGE
replicaset.apps/mysql-7dbfd4dbc4 1 1 1 2m55s
Now get the mysql-svc URL:
$ minikube service mysql-svc --url
http://192.168.99.102:32235
Try to run the book example. Again I get the two popup windows and what is shown below in the terminal. I omit the popup window text here...
$ mysql -h $(minikube service mysql-svc --format "{{.IP}}") -P $(minikube service mysql-svc --format "{{.Port}}") -u root -p
The system cannot find the file 192.168.99.102.
*
X open url failed: 192.168.99.102: exit status 1
*
* minikube is exiting due to an error. If the above message is not useful, open
an issue:
- https://github.com/kubernetes/minikube/issues/new/choose
The system cannot find the file 32235.
*
X open url failed: 32235: exit status 1
*
* minikube is exiting due to an error. If the above message is not useful, open
an issue:
- https://github.com/kubernetes/minikube/issues/new/choose
mysql: [ERROR] Unknown suffix '|' used for variable 'port' (value '|-----------|
-----------|-------------|-------|')
mysql: [ERROR] C:\Program Files\MySQL\MySQL Server 8.0\bin\mysql.exe: Error whil
e setting value '|-----------|-----------|-------------|-------|' to 'port'
I'm asked what happens if I put in the IP directly. From above, that IP was http://192.168.99.102:32235
$ mysql -h http://192.168.99.102 -P 32235 -u root -p
Enter password: **********
ERROR 2005 (HY000): Unknown MySQL server host 'http://192.168.99.102' (0)
When directly entering the IP and Port, the MySQL server IS reached (see the "Enter password:" prompt) but the request is refused. I'm thinking that I don't know how to make MySQL use the HTTP request.
But is the MySQL not knowing what to do with the IP, and the way that the indirect method (minikube service mysql -svc ...), related?
Continuing, I edit my cookbook-deployment-posts.yaml file with the MySQL address:
kind: Service
apiVersion: v1
metadata:
name: posts-svc
spec:
selector:
app: posts
ports:
- protocol: "TCP"
port: 80
targetPort: 8080
type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: posts
labels:
app: posts
spec:
replicas: 1
selector:
matchLabels:
app: posts
template:
metadata:
labels:
app: posts
spec:
containers:
- name: posts
image: cdavisafc/cloudnative-statelessness-posts
env:
- name: INSTANCE_IP
valueFrom:
fieldRef:
fieldPath: status.podIP
- name: PORT
value: "8080"
- name: SPRING_APPLICATION_JSON
value: '{"spring":{"datasource":{"url":"jdbc:mysql://192.168.99.102:32235/cookbook"}}}'
Going to kubectl get all, the posts-svc continually starts, errors out and reboots. Don't know what is wrong...
Jerome.

Answer 1

I now see a number of things going wrong.
First, I keep thinking that the mysql call is somehow related to the MySQL installed on my PC. It never is. Just because I manually create a cookbook database on my PC instance doesn't mean that the textbook example thru Docker / Minikube ever references it.
Second, the textbook is missing the --url from its minikube requests. Here is what is happening.
> kubectl create -f mysql-deployment.yaml
> minikube service mysql-svc --url
http://192.168.99.102:31030
> minikube service mysql-svc
This opens the web browser to show the service at 192.168.99.102:31030. The mysql service doesn't render a web page, but that doesn't matter to this example. The console then shows the details of the service (namespace, name, target port, url) in an ASCII box.
minikube service mysql-svc --format "{{.IP}}"
This wants to open the web browser to show the service at http://192.168.99.102, with an implied port of 80. But there is nothing there, and Windows complains at a popup box. The console then complains about not opening that url.
minikube service mysql-svc --format "{{.Port}}"
This wants to open the web browser to show the service at 31030, which isn't a valid URL. Complaints, complaints.
What I really wanted all along is to add the --url to the minikube bits:
mysql -h $(minikube service mysql-svc --format "{{.IP}}" --url) -P $(minikube service mysql-svc --format "{{.Port}}" --url) -u root -p
This connects to the managed mysql in the console, yielding the mysql> prompt. Now I can run 'create database cookbook;'.
Solved!