Connecting to MySQL 5.6 inside Docker For Desktop/Kubernetes: ERROR 1130 (HY000): Host 'xx.xx.xx.xx' is not allowed to connect to this MySQL server - mysql

Question

I'm following theses instructions (page 181) to create a persistent volume & claim, a mysql replica set & service. I specify mysql v5.6 in the yaml file for the replica set.
After viewing the log for the pod, it looks like it is successful. So then I
kubectl run -it --rm --image=mysql --restart=Never mysql-client -- bash
mysql -h mysql -p 3306 -u root
It prompts me for the password and then I get this error:
ERROR 1130 (HY000): Host '10.1.0.17' is not allowed to connect to this MySQL server
Apparently MySQL has a feature where it does not allow remote connections by default and I have to change the configuration files and I don't know how to do that inside a yaml file. Below is my YAML. How do I change it to allow remote connections?
Thanks
Siegfried
cat <<END-OF-FILE | kubectl apply -f -
apiVersion: apps/v1
kind: ReplicaSet
metadata:
name: mysql
# labels so that we can bind a Service to this Pod
labels:
app: mysql
spec:
replicas: 1
selector:
matchLabels:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
containers:
- name: tododata
image: mysql:5.6
resources:
requests:
cpu: 1
memory: 2Gi
env:
# Environment variables are not a best practice for security,
# but we're using them here for brevity in the example.
# See Chapter 11 for better options.
- name: MYSQL_ROOT_PASSWORD
value: some-password-here
livenessProbe:
tcpSocket:
port: 3306
ports:
- containerPort: 3306
volumeMounts:
- name: tododata
# /var/lib/mysql is where MySQL stores its databases
mountPath: "/var/lib/mysql"
volumes:
- name: tododata
persistentVolumeClaim:
claimName: tododata
END-OF-FILE
Sat Oct 24 2020 3PM EDT Update: Try Bitnami MySQL
I like Ben's idea of using bitnami mysql because then I don't have to create my own custom docker image. However, when using bitnami and trying to connect to they mysql server I get
ERROR 2003 (HY000): Can't connect to MySQL server on 'my-release-mysql.default.svc.cluster.local' (111)
This happens after I successfully get a bash shell with this command:
kubectl run my-release-mysql-client --rm --tty -i --restart='Never' --image docker.io/bitnami/mysql:8.0.22-debian-10-r0 --namespace default --command -- bash
Then, as per the instructions, I do this and get the HY000 error above.
mysql -h my-release-mysql.default.svc.cluster.local -uroot -p
Wed Nov 04 2020 Update:
Thanks Ben.. Yes -- I had already tried that on Oct 24 (approx) and when I do a k describe pod I get mysqladmin: connect to server at 'localhost' failed error: 'Can't connect to local MySQL server through socket '/opt/bitnami/mysql/tmp/mysql.sock' (2)' Check that mysqld is running and that the socket: '/opt/bitnami/mysql/tmp/mysql.sock' exists!.
Of course, when I run the mysql client as described in the nicely generated instructions, the client cannot connect because mysqld has died.
This is after having deleted the pvcs and stss and doing helm delete my-release prior to reinstalling via helm.
Unfortunately, when I tried this the first time (a couple of weeks ago) I did not set the root password and used the default generated password and I think it is still trying to use that.
This did work on azure kubernetes after having created a fresh azure kubernetes cluster. How can I reset my kubernetes cluster in my docker for desktop windows? I tried google searching and no luck so far.
Thanks
Siegfried

Answer 1

After a lot of help from the bitnami folks, I learned that my spinning disks on my 4 year old notebook computer are kinda slow (now why this is a problem with Bitnami MySQL and not Bitnami PostreSQL is a mystery).
This works for me:
helm install my-mysql bitnami/mysql \
--set image.debug=true \
--set primary.persistence.enabled=false,secondary.persistence.enabled=false \
--set primary.readinessProbe.enabled=false,primary.livenessProbe.enabled=false \
--set secondary.readinessProbe.enabled=false,secondary.livenessProbe.enabled=false
This turns off the peristent volumes so the data is lost when the pod dies.
Yes this is useful for me for development purposes and no one should be using Docker For Desktop/Kubernetes for production anyway... I just need to populate a tiny database and test my queries and if I need to repopulate database every time I reboot, well, that is not a big problem.
So maybe I need to get a new notebook computer? The price of notebook computers with 4TB of spinning disk space has gone up in the last couple of years.... And I cannot find any SSD drives of that size so even if I purchased a new replacement with spinning disks I might have the same problem? Hmm....
Thanks everyone for your help!
Siegfried

Answer 2

This appears to work just fine for me on windows. Complete the following steps:
helm repo add bitnami https://charts.bitnami.com/bitnami
helm install my-release --set root.password=awesomePassword bitnami/mysql
This is all you need to run the mysql instance. It does not makes a few services and a statefulset. Then, to connect to it, you
Either have to be in another another kubernetes container. Without this, you will not find the dns record for my-release-mysql.default.svc.cluster.local
run my-release-mysql-client --rm --tty -i --image docker.io/bitnami/mysql:8.0.22-debian-10-r0 --namespace default --command -- bash
mysql -h my-release-mysql.default.svc.cluster.local -uroot -p my_database
For the password, it should be 'awesomePassword'
Port forward the service to your local machine.
kubectl port-forward svc/my-release-mysql 3306:3306
As a note, a bitnami container will have issues if you kill it and restart it with only your helm commands and the password is not set. The persistent volume claim will usually stick around - so you would need to set the password to the old password. If you do not specify the password, you can get the password by running the commands bitnami tells you about.
NAME: my-release
LAST DEPLOYED: Thu Oct 29 20:39:23 2020
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES: Please be patient while the chart is being deployed
Tip:
Watch the deployment status using the command: kubectl get pods -w
--namespace default
Services:
echo Master: my-release-mysql.default.svc.cluster.local:3306 echo
Slave: my-release-mysql-slave.default.svc.cluster.local:3306
Administrator credentials:
echo Username: root echo Password : $(kubectl get secret
--namespace default my-release-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode)
To connect to your database:
Run a pod that you can use as a client:
kubectl run my-release-mysql-client --rm --tty -i --restart='Never' --image docker.io/bitnami/mysql:8.0.22-debian-10-r0 --namespace default --command -- bash
To connect to master service (read/write):
mysql -h my-release-mysql.default.svc.cluster.local -uroot -p my_database
To connect to slave service (read-only):
mysql -h my-release-mysql-slave.default.svc.cluster.local -uroot -p my_database
To upgrade this helm chart:
Obtain the password as described on the 'Administrator credentials' section and set the 'root.password' parameter as shown
below:
ROOT_PASSWORD=$(kubectl get secret --namespace default my-release-mysql -o jsonpath="{.data.mysql-root-password}" | base64
--decode)
helm upgrade my-release bitnami/mysql --set root.password=$ROOT_PASSWORD