G033 - Deploying services 02 ~ Nextcloud - Part 3 - MariaDB database server

The Nextcloud platform needs a database and MariaDB is the database engine chosen for this task.

MariaDB Kustomize project's folders

Since the MariaDB database is just another component of your Nextcloud platform, you'll have to put its corresponding folders within the nextcloud/components path you created already in the previous Redis guide.

$ mkdir -p $HOME/k8sprjs/nextcloud/components/db-mariadb/{configs,resources,secrets}

Like Redis, MariaDB also has configurations, secrets and resources files making up its Kustomize setup.

MariaDB configuration files

The MariaDB deployment requires a lot of adjustments that have to be handled in configuration files.

Configuration file `my.cnf`

The my.cnf is the default configuration file for MariaDB. In it you can adjust many parameters of this database engine, something you'll need to do in this case.

Create a my.cnf file in the configs folder.

$ touch $HOME/k8sprjs/nextcloud/components/db-mariadb/configs/my.cnf

Edit my.cnf to put in it the configuration below.
```
[server]
skip_name_resolve = 1
innodb_buffer_pool_size = 224M
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 32M
query_cache_type = 1
query_cache_limit = 2M
query_cache_min_res_unit = 2k
query_cache_size = 64M
slow_query_log = 1
slow_query_log_file = /var/lib/mysql/slow.log
long_query_time = 1
innodb_io_capacity = 2000
innodb_io_capacity_max = 3000

[client-server]
!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mariadb.conf.d/

[client]
default-character-set = utf8mb4

[mysqld]
character_set_server = utf8mb4
collation_server = utf8mb4_general_ci
transaction_isolation = READ-COMMITTED
binlog_format = ROW
log_bin = /var/lib/mysql/mysql-bin.log
expire_logs_days = 7
max_binlog_size = 100M
innodb_file_per_table=1
innodb_read_only_compressed = OFF
tmp_table_size= 32M
max_heap_table_size= 32M
max_connections=512
```
The my.cnf above is a modified version of an example found in the official Nexcloud documentation.
- This configuration fits the requirements of transaction isolation level (READ-COMMITED) and binlog format (ROW) demanded by Nextcloud.
- The innodb_buffer_pool_size parameter preconfigures the size of the buffer pool in memory, which should have between the 60% and the 80% of the RAM available for MariaDB.
- The innodb_io_capacity and innodb_io_capacity_max parameters are related to the I/O capacity of the underlying storage. Here they've been increased from their default values to fit better the ssd volume used for storing the MariaDB data.
- The character set configured is utf8mb4, which is wider than the regular utf8 one.
- Nextcloud uses table compression, but writing in such format comes disabled by default since MariaDB 10.6. To enable it, the innodb_read_only_compressed parameter has to be set as OFF.
- With max_connections, it limits the maximum connections that can connect to the instance.

Properties file `dbnames.properties`

There are a few names you need to specify in your database setup. Those names are values that you want to load as variables in the server container rather than typing them directly on MariaDB's configuration.

Create a dbnames.properties file under the configs path.

$ touch $HOME/k8sprjs/nextcloud/components/db-mariadb/configs/dbnames.properties

Copy the following parameter lines into dbnames.properties.
```
nextcloud-db-name=nextcloud-db
nextcloud-username=nextcloud
prometheus-exporter-username=exporter
```
The three key-value pairs above mean the following.
- nextcloud-db-name: name for the Nexcloud's database.
- nextcloud-username: name for the user associated to the Nextcloud's database.
- prometheus-exporter-username: name for the Prometheus metrics exporter user.

Initializer shell script `initdb.sh`

The Prometheus metrics exporter system you'll include in the MariaDB's deployment requires its own user to access certain statistical data from your MariaDB instance. You've already configured its name as a variable in the previous dbnames.properties file, but you also need to create the user within the MariaDB installation. The problem is that MariaDB can only create one user in its initial run, and you need also to create the user Nextcloud needs to work with its own database.

To solve this issue, you can use a initializer shell script that creates that extra user you need in the MariaDB database.

Create a initdb.sh file in the configs directory.

$ touch $HOME/k8sprjs/nextcloud/components/db-mariadb/configs/initdb.sh

Fill the initdb.sh file with the following shell script.
```
#!/bin/sh
echo ">>> Creating user for Mysql Prometheus metrics exporter"
mysql -u root -p$MYSQL_ROOT_PASSWORD --execute \
"CREATE USER '${MARIADB_PROMETHEUS_EXPORTER_USERNAME}'@'localhost' IDENTIFIED BY '${MARIADB_PROMETHEUS_EXPORTER_PASSWORD}' WITH MAX_USER_CONNECTIONS 3;
GRANT PROCESS, REPLICATION CLIENT, SELECT ON *.* TO '${MARIADB_PROMETHEUS_EXPORTER_USERNAME}'@'localhost';
FLUSH privileges;"
```
See that the script what in fact does is execute some SQL code through a mysql command to create the required user. And notice how, instead of putting raw values, environmental variables (MARIADB_PROMETHEUS_EXPORTER_USERNAME and MARIADB_PROMETHEUS_EXPORTER_PASSWORD) are used as placeholders for several values. Those variables will be defined within the Deployment resource definition you'll prepare later in this guide.

MariaDB passwords

There's a number of passwords you need to set up in the MariaDB installation.

The MariaDB root user's password.
The Nextcloud database user's password.
The Prometheus metrics exporter user's password.

For convenience, let's declare all these passwords as variables in the same properties file, so they can be turned into a Secret resource later.

Create a dbusers.pwd file under the secrets path.

$ touch $HOME/k8sprjs/nextcloud/components/db-mariadb/secrets/dbusers.pwd

Fill dbusers.pwd with the following variables.

root-password=l0nG.Pl4in_T3xt_sEkRet_p4s5wORD-FoR_rOo7_uZ3r!
nextcloud-user-password=l0nG.Pl4in_T3xt_sEkRet_p4s5wORD-FoR_nEx7k1OuD_uZ3r!
prometheus-exporter-password=l0nG.Pl4in_T3xt_sEkRet_p4s5wORD-FoR_3xP0rTeR_uZ3r!

The passwords have to be put here as plain unencrypted text, so be careful of who accesses this file.

MariaDB storage

Storage in Kubernetes has essentially two sides: the enablement of storage as persistent volumes (PVs), and the claims (PVCs) on each of those persistent volumes. For MariaDB you'll need one persistent volume, which you'll declare in the last part of this Nextcloud guide, and the claim on that particular PV.

A persistent volume claim is a resource, so create a db-mariadb.persistentvolumeclaim.yaml file under the resources folder.
```
$ touch $HOME/k8sprjs/nextcloud/components/db-mariadb/resources/db-mariadb.persistentvolumeclaim.yaml
```
Copy the yaml manifest below into db-mariadb.persistentvolumeclaim.yaml.
```
apiVersion: v1
kind: PersistentVolumeClaim

metadata:
  name: db-mariadb
spec:
  accessModes:
  - ReadWriteOnce
  storageClassName: local-path
  volumeName: db-nextcloud
  resources:
    requests:
      storage: 3.5G
```
There are a few details to understand from the PVC above.
- The spec.accessModes is specified. This is mandatory in a claim and it cannot demand a mode that's not enabled in the persistent volume itself.
- The spec.storageClassName is a parameter that indicates what storage profile (a particular set of properties) to use with the persistent volume. K3s comes with just the local-path included by default, something you can check out on your own K3s cluster with kubectl.
```
$ kubectl get storageclass
NAME                   PROVISIONER             RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
local-path (default)   rancher.io/local-path   Delete          WaitForFirstConsumer   false                  10d
```
- The spec.volumeName is the name of the persistent volume, in the same namespace, this claim binds itself to.
- In a claim is also mandatory to specify how much storage is requested, hence the need to put the spec.resources.requests.storage parameter there. Be careful of not requesting more space than what's available in the volume.
- Needless to say, but the persistent volume related to this claim must correspond to the values set here.

MariaDB StatefulSet resource

Instead of using a Deployment resource to put MariaDB in your Kubernetes cluster, you'll use a StatefulSet. Stateful sets are meant for deploying apps or services that store data (state) permanently, as databases such as MariaDB do.

Create a db-mariadb.statefulset.yaml in the resources path.

$ touch $HOME/k8sprjs/nextcloud/components/db-mariadb/resources/db-mariadb.statefulset.yaml

Put in db-mariadb.statefulset.yaml the next resource description.

apiVersion: apps/v1
kind: StatefulSet

metadata:
  name: db-mariadb
spec:
  replicas: 1
  serviceName: db-mariadb
  template:
    spec:
      containers:
      - name: server
        image: mariadb:10.6-focal
        ports:
        - containerPort: 3306
        env:
        - name: MYSQL_DATABASE
          valueFrom:
            configMapKeyRef:
              name: db-mariadb
              key: nextcloud-db-name
        - name: MYSQL_ROOT_PASSWORD
          valueFrom:
            secretKeyRef:
              name: db-mariadb
              key: root-password
        - name: MYSQL_USER
          valueFrom:
            configMapKeyRef:
              name: db-mariadb
              key: nextcloud-username
        - name: MYSQL_PASSWORD
          valueFrom:
            secretKeyRef:
              name: db-mariadb
              key: nextcloud-user-password
        - name: MARIADB_PROMETHEUS_EXPORTER_USERNAME
          valueFrom:
            configMapKeyRef:
              name: db-mariadb
              key: prometheus-exporter-username
        - name: MARIADB_PROMETHEUS_EXPORTER_PASSWORD
          valueFrom:
            secretKeyRef:
              name: db-mariadb
              key: prometheus-exporter-password
        resources:
          limits:
            memory: 320Mi
        volumeMounts:
        - name: mariadb-config 
          subPath: my.cnf
          mountPath: /etc/mysql/my.cnf
        - name: mariadb-config 
          subPath: initdb.sh
          mountPath: /docker-entrypoint-initdb.d/initdb.sh
        - name: mariadb-storage
          mountPath: /var/lib/mysql
      - name: metrics
        image: prom/mysqld-exporter:v0.13.0
        ports:
        - containerPort: 9104
        args:
        - --collect.info_schema.tables
        - --collect.info_schema.innodb_tablespaces
        - --collect.info_schema.innodb_metrics
        - --collect.global_status
        - --collect.global_variables
        - --collect.slave_status
        - --collect.info_schema.processlist
        - --collect.perf_schema.tablelocks
        - --collect.perf_schema.eventsstatements
        - --collect.perf_schema.eventsstatementssum
        - --collect.perf_schema.eventswaits
        - --collect.auto_increment.columns
        - --collect.binlog_size
        - --collect.perf_schema.tableiowaits
        - --collect.perf_schema.indexiowaits
        - --collect.info_schema.userstats
        - --collect.info_schema.clientstats
        - --collect.info_schema.tablestats
        - --collect.info_schema.schemastats
        - --collect.perf_schema.file_events
        - --collect.perf_schema.file_instances
        - --collect.perf_schema.replication_group_member_stats
        - --collect.perf_schema.replication_applier_status_by_worker
        - --collect.slave_hosts
        - --collect.info_schema.innodb_cmp
        - --collect.info_schema.innodb_cmpmem
        - --collect.info_schema.query_response_time
        - --collect.engine_tokudb_status
        - --collect.engine_innodb_status
        env:
        - name: MARIADB_PROMETHEUS_EXPORTER_USERNAME
          valueFrom:
            configMapKeyRef:
              name: db-mariadb
              key: prometheus-exporter-username
        - name: MARIADB_PROMETHEUS_EXPORTER_PASSWORD
          valueFrom:
            secretKeyRef:
              name: db-mariadb
              key: prometheus-exporter-password
        - name: DATA_SOURCE_NAME
          value: "$(MARIADB_PROMETHEUS_EXPORTER_USERNAME):$(MARIADB_PROMETHEUS_EXPORTER_PASSWORD)@(localhost:3306)/"
        resources:
          limits:
            memory: 32Mi
      volumes:
      - name: mariadb-config
        configMap:
          name: db-mariadb
          items:
          - key: initdb.sh
            path: initdb.sh
          - key: my.cnf
            path: my.cnf
      - name: mariadb-storage
        persistentVolumeClaim:
          claimName: db-mariadb

If you compare this StatefulSet with Redis' Deployment you'll find many similarities regarding parameters, but there are also several differences.

serviceName: links this StatefulSet to a Service.

BEWARE!
A StatefulSet can only be linked to an already existing Service.
template.spec.containers: like in the Redis case, two containers are set in the pod as sidecars.
- Container server: the MariaDB server instance.
  - The image of MariaDB here is based on the Focal Fossa version (20.04 LTS) of Ubuntu.
  - The env section contains several environment parameters. The ones with the MYSQL_ prefix are directly recognized by the MariaDB server. The MARIADB_PROMETHEUS_EXPORTER_USERNAME and MARIADB_PROMETHEUS_EXPORTER_PASSWORD are meant only for the initdb.sh initializer script. Notice how the values of these environment parameters are taken from a db-mariadb secret and a db-mariadb config map you'll declare later.
  - The volumeMounts contains three mount points.
    - MountPath /etc/mysql/my.cnf: the default path where MariaDB has its my.cnf file. This my.cnf file is the one you created before, and you'll load it later in the db-mariadb config map resource.
    - MountPath /docker-entrypoint-initdb.d/initdb.sh: the path /docker-entrypoint-initdb.d is a special one within the MariaDB container, prepared to execute (in alphabetical order) any shell or SQL scripts you put in here just the first time this container is executed. This way you can initialize databases or create extra users, as your initdb.sh script does. You'll also include initdb.sh in the db-mariadb config map resource.
    - MountPath /var/lib/mysql: this is the default data folder of MariaDB. It's where the volume mariadb-storage's filesystem will be mounted into.
- Container metrics: the Prometheus metrics exporter service related to the MariaDB server.
  - The image of this exporter is not clear on what Linux Distribution is based, although probably is Debian.
  - In args are set a number of parameters meant for the command launching the service in the container.
  - In env you have the environment parameters MARIADB_PROMETHEUS_EXPORTER_USERNAME and MARIADB_PROMETHEUS_EXPORTER_PASSWORD you already saw in the definition of the MariaDB container. They're defined here so the next environment parameter, DATA_SOURCE_NAME, can use them. This last parameter is required for this Prometheus metrics service to connect to the MariaDB instance with its own user (the one created by the initdb.sh script that initializes MariaDB). Also see how the URL it connects to is localhost:3306, because the two containers are running in the same pod.
template.spec.volumes: sets the storage volumes that are to be used in the pod described in this template.
- With name mariadb-config: the my.cnf and initdb.sh files are enabled here as volumes. The files will have the permission mode 644 by default in the container that mounts them.
- With name mariadb-storage: here the PersistentVolumeClaim named db-mariadb is enabled as a volume called mariadb-storage.

MariaDB Service resource

The previous StatefulSet requires a Service named db-mariadb to run, so you need to declare it.

Create a file named db-mariadb.service.yaml under resources.

$ touch $HOME/k8sprjs/nextcloud/components/db-mariadb/resources/db-mariadb.service.yaml

Edit db-mariadb.service.yaml and put the following yaml in it.

apiVersion: v1
kind: Service

metadata:
  annotations:
    prometheus.io/scrape: "true"
    prometheus.io/port: "9104"
  name: db-mariadb
spec:
  type: ClusterIP
  clusterIP: 10.43.100.2
  ports:
  - port: 3306
    protocol: TCP
    name: server
  - port: 9104
    protocol: TCP
    name: metrics

The main things to notice here is that the cluster IP is the one you've chosen beforehand and the port numbers correspond with the ones configured as containerPorts in the MariaDB's StatefulSet.

MariaDB Kustomize project

Now you have to create the main kustomization.yaml file describing your MariaDB Kustomize project.

Under db-mariadb, create a kustomization.yaml file.

$ touch $HOME/k8sprjs/nextcloud/components/db-mariadb/kustomization.yaml

Fill kustomization.yaml with the yaml definition below.

# MariaDB setup
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

commonLabels:
  app: db-mariadb

resources:
- resources/db-mariadb.persistentvolumeclaim.yaml
- resources/db-mariadb.service.yaml
- resources/db-mariadb.statefulset.yaml

replicas:
- name: db-mariadb
  count: 1

images:
- name: mariadb
  newTag: 10.6-focal
- name: prom/mysqld-exporter
  newTag: v0.13.0

configMapGenerator:
- name: db-mariadb
  envs:
  - configs/dbnames.properties
  files:
  - configs/initdb.sh
  - configs/my.cnf

secretGenerator:
- name: db-mariadb
  envs:
  - secrets/dbusers.pwd

This kustomization.yaml is very similar to the one you did for Redis, with the main difference being in the generator sections.

The configMapGenerator sets up one ConfigMap resource called db-mariadb. When generated, it'll contain the two archives specified under files and all the key-value pairs included in the file referenced in envs.
The secretGenerator prepares one Secret resource named db-mariadb that only contains the key-value sets within the file pointed at in the envs section.

Checking the Kustomize yaml output

At this point, you can verify with kubectl that the Kustomize project for MariaDB gives you the proper yaml output.

Execute kubectl kustomize and pipe the yaml output on the less command or dump it on a file.
```
$ kubectl kustomize $HOME/k8sprjs/nextcloud/components/db-mariadb | less
```

See that your yaml output is like the one below.

apiVersion: v1
data:
  initdb.sh: |
    #!/bin/sh
    echo ">>> Creating user for Mysql Prometheus metrics exporter"
    mysql -u root -p$MYSQL_ROOT_PASSWORD --execute \
    "CREATE USER '${MARIADB_PROMETHEUS_EXPORTER_USERNAME}'@'localhost' IDENTIFIED BY '${MARIADB_PROMETHEUS_EXPORTER_PASSWORD}' WITH MAX_USER_CONNECTIONS 3;
    GRANT PROCESS, REPLICATION CLIENT, SELECT ON *.* TO '${MARIADB_PROMETHEUS_EXPORTER_USERNAME}'@'localhost';
    FLUSH privileges;"
  my.cnf: |
    [server]
    skip_name_resolve = 1
    innodb_buffer_pool_size = 224M
    innodb_flush_log_at_trx_commit = 2
    innodb_log_buffer_size = 32M
    query_cache_type = 1
    query_cache_limit = 2M
    query_cache_min_res_unit = 2k
    query_cache_size = 64M
    slow_query_log = 1
    slow_query_log_file = /var/lib/mysql/slow.log
    long_query_time = 1
    innodb_io_capacity = 2000
    innodb_io_capacity_max = 3000

    [client-server]
    !includedir /etc/mysql/conf.d/
    !includedir /etc/mysql/mariadb.conf.d/

    [client]
    default-character-set = utf8mb4

    [mysqld]
    character_set_server = utf8mb4
    collation_server = utf8mb4_general_ci
    transaction_isolation = READ-COMMITTED
    binlog_format = ROW
    log_bin = /var/lib/mysql/mysql-bin.log
    expire_logs_days = 7
    max_binlog_size = 100M
    innodb_file_per_table=1
    innodb_read_only_compressed = OFF
    tmp_table_size= 32M
    max_heap_table_size= 32M
    max_connections=512
  nextcloud-db-name: nextcloud-db
  nextcloud-username: nextcloud
  prometheus-exporter-username: exporter
kind: ConfigMap
metadata:
  labels:
    app: db-mariadb
  name: db-mariadb-88gc2m5h46
---
apiVersion: v1
data:
  nextcloud-user-password: |
    cTQ4OXE1NjlnYWRmamzDsWtqcXdpb2VrbnZrbG5rd2VvbG12bGtqYcOxc2RnYWlvcGgyYXNkZmFz
    a2RrbmZnbDIK
  prometheus-exporter-password: |
    bmd1ZXVlaTVpdG52Ym52amhha29hb3BkcGRrY25naGZ1ZXI5MzlrZTIwMm1mbWZ2bHNvc2QwM2Zr
    ZDkyM2zDsQo=
  root-password: |
    MDk0ODM1bXZuYjg5MDM4N212Mmk5M21jam5yamhya3Nkw7Fzb3B3ZWpmZ212eHNvZWRqOTNkam1k
    bDI5ZG1qego=
kind: Secret
metadata:
  labels:
    app: db-mariadb
  name: db-mariadb-dg5cm45947
type: Opaque
---
apiVersion: v1
kind: Service
metadata:
  annotations:
    prometheus.io/port: "9104"
    prometheus.io/scrape: "true"
  labels:
    app: db-mariadb
  name: db-mariadb
spec:
  clusterIP: 10.43.100.2
  ports:
  - name: server
    port: 3306
    protocol: TCP
  - name: metrics
    port: 9104
    protocol: TCP
  selector:
    app: db-mariadb
  type: ClusterIP
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  labels:
    app: db-mariadb
  name: db-mariadb
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 3.5G
  storageClassName: local-path
  volumeName: db-nextcloud
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  labels:
    app: db-mariadb
  name: db-mariadb
spec:
  replicas: 1
  selector:
    matchLabels:
      app: db-mariadb
  serviceName: db-mariadb
  template:
    metadata:
      labels:
        app: db-mariadb
    spec:
      containers:
      - env:
        - name: MYSQL_DATABASE
          valueFrom:
            configMapKeyRef:
              key: nextcloud-db-name
              name: db-mariadb-88gc2m5h46
        - name: MYSQL_ROOT_PASSWORD
          valueFrom:
            secretKeyRef:
              key: root-password
              name: db-mariadb-dg5cm45947
        - name: MYSQL_USER
          valueFrom:
            configMapKeyRef:
              key: nextcloud-username
              name: db-mariadb-88gc2m5h46
        - name: MYSQL_PASSWORD
          valueFrom:
            secretKeyRef:
              key: nextcloud-user-password
              name: db-mariadb-dg5cm45947
        - name: MARIADB_PROMETHEUS_EXPORTER_USERNAME
          valueFrom:
            configMapKeyRef:
              key: prometheus-exporter-username
              name: db-mariadb-88gc2m5h46
        - name: MARIADB_PROMETHEUS_EXPORTER_PASSWORD
          valueFrom:
            secretKeyRef:
              key: prometheus-exporter-password
              name: db-mariadb-dg5cm45947
        image: mariadb:10.6-focal
        name: server
        ports:
        - containerPort: 3306
        resources:
          limits:
            memory: 320Mi
        volumeMounts:
        - mountPath: /etc/mysql/my.cnf
          name: mariadb-config
          subPath: my.cnf
        - mountPath: /docker-entrypoint-initdb.d/initdb.sh
          name: mariadb-config
          subPath: initdb.sh
        - mountPath: /var/lib/mysql
          name: mariadb-storage
      - args:
        - --collect.info_schema.tables
        - --collect.info_schema.innodb_tablespaces
        - --collect.info_schema.innodb_metrics
        - --collect.global_status
        - --collect.global_variables
        - --collect.slave_status
        - --collect.info_schema.processlist
        - --collect.perf_schema.tablelocks
        - --collect.perf_schema.eventsstatements
        - --collect.perf_schema.eventsstatementssum
        - --collect.perf_schema.eventswaits
        - --collect.auto_increment.columns
        - --collect.binlog_size
        - --collect.perf_schema.tableiowaits
        - --collect.perf_schema.indexiowaits
        - --collect.info_schema.userstats
        - --collect.info_schema.clientstats
        - --collect.info_schema.tablestats
        - --collect.info_schema.schemastats
        - --collect.perf_schema.file_events
        - --collect.perf_schema.file_instances
        - --collect.perf_schema.replication_group_member_stats
        - --collect.perf_schema.replication_applier_status_by_worker
        - --collect.slave_hosts
        - --collect.info_schema.innodb_cmp
        - --collect.info_schema.innodb_cmpmem
        - --collect.info_schema.query_response_time
        - --collect.engine_tokudb_status
        - --collect.engine_innodb_status
        env:
        - name: MARIADB_PROMETHEUS_EXPORTER_USERNAME
          valueFrom:
            configMapKeyRef:
              key: prometheus-exporter-username
              name: db-mariadb-88gc2m5h46
        - name: MARIADB_PROMETHEUS_EXPORTER_PASSWORD
          valueFrom:
            secretKeyRef:
              key: prometheus-exporter-password
              name: db-mariadb-dg5cm45947
        - name: DATA_SOURCE_NAME
          value: $(MARIADB_PROMETHEUS_EXPORTER_USERNAME):$(MARIADB_PROMETHEUS_EXPORTER_PASSWORD)@(localhost:3306)/
        image: prom/mysqld-exporter:v0.13.0
        name: metrics
        ports:
        - containerPort: 9104
        resources:
          limits:
            memory: 32Mi
      volumes:
      - configMap:
          items:
          - key: initdb.sh
            path: initdb.sh
          - key: my.cnf
            path: my.cnf
          name: db-mariadb-88gc2m5h46
        name: mariadb-config
      - name: mariadb-storage
        persistentVolumeClaim:
          claimName: db-mariadb

Pay particular attention to the ConfigMap and Secret resources declared in the output.

Their names have a hash as a suffix appended to their names.
The db-mariadb config map has the initdb.sh and my.cnf loaded in it (filenames as keys and their full contents as values), and the key-value pairs found in dbnames.properties are set independently.
The db-mariadb secret has all the key-value pairs set in the dbusers.pwd but with the particularity that the values have been automatically encoded in base64.

Remember that, if you dumped the Kustomize output into a yaml file, you can validate it with kubeval.

Don't deploy this MariaDB project on its own

This MariaDB setup is missing one critical element, the persistent volume it needs to store data and which you must not confuse with the claim you've configured for your MariaDB server. That PV and other elements will be declared in the main Kustomize project you'll prepare in the final part of this guide. Till then, don't deploy this setup of MariaDB.

Relevant system paths

Folders in `kubectl` client system

$HOME/k8sprjs/nextcloud/components/db-mariadb
$HOME/k8sprjs/nextcloud/components/db-mariadb/configs
$HOME/k8sprjs/nextcloud/components/db-mariadb/resources
$HOME/k8sprjs/nextcloud/components/db-mariadb/secrets

Files in `kubectl` client system

$HOME/k8sprjs/nextcloud/components/db-mariadb/kustomization.yaml
$HOME/k8sprjs/nextcloud/components/db-mariadb/configs/dbnames.properties
$HOME/k8sprjs/nextcloud/components/db-mariadb/configs/initdb.sh
$HOME/k8sprjs/nextcloud/components/db-mariadb/configs/my.cnf
$HOME/k8sprjs/nextcloud/components/db-mariadb/resources/db-mariadb.persistentvolumeclaim.yaml
$HOME/k8sprjs/nextcloud/components/db-mariadb/resources/db-mariadb.service.yaml
$HOME/k8sprjs/nextcloud/components/db-mariadb/resources/db-mariadb.statefulset.yaml
$HOME/k8sprjs/nextcloud/components/db-mariadb/secrets/dbusers.pwd

References

Kubernetes

ConfigMaps and secrets

Official Doc - ConfigMaps
Official Doc - Configure a Pod to Use a ConfigMap
An Introduction to Kubernetes Secrets and ConfigMaps
Kubernetes - Using ConfigMap SubPaths to Mount Files
Kubernetes Secrets | Declare confidential data with examples
Kubernetes ConfigMaps and Secrets
Import data to config map from kubernetes secret

Storage

Official Doc - Local Storage Volumes
Official Doc - Local Persistent Volumes for Kubernetes Goes Beta
Official Doc - Reserving a PersistentVolume
Official Doc - Local StorageClass
Official Doc - Reclaiming Persistent Volumes
Kubernetes API - PersistentVolume
Kubernetes API - PersistentVolumeClaim
Kubernetes Persistent Volumes, Claims, Storage Classes, and More
Rancher K3s - Setting up the Local Storage Provider
K3s local path provisioner on GitHub
Using "local-path" in persistent volume requires sudo to edit files on host node?
Kubernetes size definitions: What's the difference of "Gi" and "G"?
distinguish unset and empty values for storageClassName
Kubernetes Mounting Volumes in Pods. Mount Path Ownership and Permissions

StatefulSets

Official Doc

Environment variables

Official Doc - Define Environment Variables for a Container
Official Doc - Define Dependent Environment Variables

MariaDB

MariaDB
MariaDB on DockerHub
MySQL Server Exporter on GitHub
MySQL Server Prometheus Exporter
Using Prometheus to Monitor MySQL and MariaDB
Server System Variables
Configuring MariaDB with Option Files
Add another user to MySQL in Kubernetes
Initialize a fresh instance of Mariadb
using environment variables in docker-compose mounted files for initializing mysql
How to initialize mysql container when created on Kubernetes?
import mysql data to kubernetes pod
Binary Log Formats
How to Enable and Use Binary Log in MySQL/MariaDB
How to Change a Default MySQL/MariaDB Data Directory in Linux
mysql Command-line Client
How to see/get a list of MySQL/MariaDB users accounts
Introduction to four key MariaDB client commands
How to fix Nextcloud 4047 InnoDB refuses to write tables with ROW_FORMAT=COMPRESSED or KEY_BLOCK_SIZE
Mariadb 10.6 won't allow writing in compressed innodb by default
Configuring MariaDB for Optimal Performance
15 Useful MySQL/MariaDB Performance Tuning and Optimization Tips
Analyze MySQL Performance
Setup innodb_io_capacity

Nextcloud

Database configuration

Navigation

<< Previous (G033. Deploying services 02. Nextcloud Part 2) | +Table Of Contents+ | Next (G033. Deploying services 02. Nextcloud Part 4) >>

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

G033 - Deploying services 02 ~ Nextcloud - Part 3 - MariaDB database server.md

G033 - Deploying services 02 ~ Nextcloud - Part 3 - MariaDB database server.md

G033 - Deploying services 02 ~ Nextcloud - Part 3 - MariaDB database server

MariaDB Kustomize project's folders

MariaDB configuration files

Configuration file `my.cnf`

Properties file `dbnames.properties`

Initializer shell script `initdb.sh`

MariaDB passwords

MariaDB storage

MariaDB StatefulSet resource

MariaDB Service resource

MariaDB Kustomize project

Checking the Kustomize yaml output

Don't deploy this MariaDB project on its own

Relevant system paths

Folders in `kubectl` client system

Files in `kubectl` client system

References

Kubernetes

ConfigMaps and secrets

Storage

StatefulSets

Environment variables

MariaDB

Nextcloud

Navigation

Files

G033 - Deploying services 02 ~ Nextcloud - Part 3 - MariaDB database server.md

Latest commit

History

G033 - Deploying services 02 ~ Nextcloud - Part 3 - MariaDB database server.md

File metadata and controls

G033 - Deploying services 02 ~ Nextcloud - Part 3 - MariaDB database server

MariaDB Kustomize project's folders

MariaDB configuration files

Configuration file my.cnf

Properties file dbnames.properties

Initializer shell script initdb.sh

MariaDB passwords

MariaDB storage

MariaDB StatefulSet resource

MariaDB Service resource

MariaDB Kustomize project

Checking the Kustomize yaml output

Don't deploy this MariaDB project on its own

Relevant system paths

Folders in kubectl client system

Files in kubectl client system

References

Kubernetes

ConfigMaps and secrets

Storage

StatefulSets

Environment variables

MariaDB

Nextcloud

Navigation

Configuration file `my.cnf`

Properties file `dbnames.properties`

Initializer shell script `initdb.sh`

Folders in `kubectl` client system

Files in `kubectl` client system