Mysql and Wordpress Kubernetes installtion giving Name Resolution Error

3/11/2019

I am trying to install wordpress on kubernetes using NFS as a persistent volume. so far I have followed steps from below link.

Install Wordpress

I am able to successfully install the mysql and mysql Pod displays the below messages.

MySQL init process done. Ready for start up.

2019-03-11 12:23:54 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2019-03-11 12:23:54 0 [Note] mysqld (mysqld 5.6.43) starting as process 1 ...
2019-03-11 12:23:54 1 [Note] Plugin 'FEDERATED' is disabled.
2019-03-11 12:23:54 1 [Note] InnoDB: Using atomics to ref count buffer pool pages
2019-03-11 12:23:54 1 [Note] InnoDB: The InnoDB memory heap is disabled
2019-03-11 12:23:54 1 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2019-03-11 12:23:54 1 [Note] InnoDB: Memory barrier is not used
2019-03-11 12:23:54 1 [Note] InnoDB: Compressed tables use zlib 1.2.11
2019-03-11 12:23:54 1 [Note] InnoDB: Using Linux native AIO
2019-03-11 12:23:54 1 [Note] InnoDB: Using CPU crc32 instructions
2019-03-11 12:23:54 1 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2019-03-11 12:23:54 1 [Note] InnoDB: Completed initialization of buffer pool
2019-03-11 12:23:54 1 [Note] InnoDB: Highest supported file format is Barracuda.
2019-03-11 12:23:54 1 [Note] InnoDB: 128 rollback segment(s) are active.
2019-03-11 12:23:54 1 [Note] InnoDB: Waiting for purge to start
2019-03-11 12:23:54 1 [Note] InnoDB: 5.6.43 started; log sequence number 1625997
2019-03-11 12:23:54 1 [Note] Server hostname (bind-address): '*'; port: 3306
2019-03-11 12:23:54 1 [Note] IPv6 is available.
2019-03-11 12:23:54 1 [Note]   - '::' resolves to '::';
2019-03-11 12:23:54 1 [Note] Server socket created on IP: '::'.
2019-03-11 12:23:54 1 [Warning] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory.
2019-03-11 12:23:54 1 [Warning] 'proxies_priv' entry '@ root@mysql-65db44d76-ss9g7' ignored in --skip-name-resolve mode.
2019-03-11 12:23:54 1 [Note] Event Scheduler: Loaded 0 events
2019-03-11 12:23:54 1 [Note] mysqld: ready for connections.
Version: '5.6.43'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  MySQL Community Server (GPL)

Now when I create a Wordpress Deployment, it shows the below errors

kubi@kubem:~/wordpress2$ kubectl logs -f wordpress-67bbb57489-glm5r

Warning: mysqli::__construct(): php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution in Standard input code on line 22

Warning: mysqli::__construct(): (HY000/2002): php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution in Standard input code on line 22

MySQL Connection Error: (2002) php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution

Here are the Both Wordpress POD and Mysql POD describe :

Wordpress --

kubi@kubem:~/wordpress2$ kubectl describe  pod wordpress-67bbb57489-glm5r
Name:               wordpress-67bbb57489-glm5r
Namespace:          default
Priority:           0
PriorityClassName:  <none>
Node:               kubew1/192.168.56.111
Start Time:         Mon, 11 Mar 2019 13:26:56 +0100
Labels:             app=wordpress
                    pod-template-hash=67bbb57489
                    tier=frontend
Annotations:        <none>
Status:             Running
IP:                 10.244.1.48
Controlled By:      ReplicaSet/wordpress-67bbb57489
Containers:
  wordpress:
    Container ID:   docker://06e30ceddb0ebfdb9c71b597d538d2e58bc306d63837fa2d48447ec547ff23b5
    Image:          wordpress:latest
    Image ID:       docker-pullable://wordpress@sha256:08c71170cdd4427d155906f8eb0e715768c133f836780c97b0e3cc3e7c1288e2
    Port:           80/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Mon, 11 Mar 2019 13:34:56 +0100
    Last State:     Terminated
      Reason:       Error
      Exit Code:    1
      Started:      Mon, 11 Mar 2019 13:30:52 +0100
      Finished:     Mon, 11 Mar 2019 13:34:39 +0100
    Ready:          True
    Restart Count:  2
    Environment:
      WORDPRESS_DB_HOST:      mysql
      WORDPRESS_DB_PASSWORD:  <set to the key 'password.txt' in secret 'mysql-pass'>  Optional: false
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-fl5nc (ro)
      /var/www/html from wordpress-local-storage (rw)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  wordpress-local-storage:
    Type:    EmptyDir (a temporary directory that shares a pod's lifetime)
    Medium:  
  default-token-fl5nc:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-fl5nc
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type     Reason     Age                  From               Message
  ----     ------     ----                 ----               -------
  Normal   Scheduled  11m                  default-scheduler  Successfully assigned default/wordpress-67bbb57489-glm5r to kubew1
  Warning  BackOff    4m                   kubelet, kubew1    Back-off restarting failed container
  Normal   Pulling    3m48s (x3 over 11m)  kubelet, kubew1    pulling image "wordpress:latest"
  Normal   Pulled     3m45s (x3 over 11m)  kubelet, kubew1    Successfully pulled image "wordpress:latest"
  Normal   Created    3m44s (x3 over 11m)  kubelet, kubew1    Created container
  Normal   Started    3m44s (x3 over 11m)  kubelet, kubew1    Started container

Mysql --

Name:               mysql-65db44d76-ss9g7
Namespace:          default
Priority:           0
PriorityClassName:  <none>
Node:               kubew2/192.168.56.112
Start Time:         Mon, 11 Mar 2019 13:23:46 +0100
Labels:             app=wordpress
                    pod-template-hash=65db44d76
                    tier=mysql
Annotations:        <none>
Status:             Running
IP:                 10.244.2.41
Controlled By:      ReplicaSet/mysql-65db44d76
Containers:
  mysql:
    Container ID:   docker://4758a3a3fe6dbce6cfa185949c7b987019a2003d7f09924c182b36574290d9c7
    Image:          mysql:5.6
    Image ID:       docker-pullable://mysql@sha256:36cad5daaae69fbcc15dd33b9f25f35c41bbe7e06cb7df5e14d8b966fb26c1b4
    Port:           3306/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Mon, 11 Mar 2019 13:23:47 +0100
    Ready:          True
    Restart Count:  0
    Environment:
      MYSQL_ROOT_PASSWORD:  <set to the key 'password.txt' in secret 'mysql-pass'>  Optional: false
    Mounts:
      /var/lib/mysql from mysql-local-storage (rw)
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-fl5nc (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  mysql-local-storage:
    Type:    EmptyDir (a temporary directory that shares a pod's lifetime)
    Medium:  
  default-token-fl5nc:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-fl5nc
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type    Reason     Age   From               Message
  ----    ------     ----  ----               -------
  Normal  Scheduled  16m   default-scheduler  Successfully assigned default/mysql-65db44d76-ss9g7 to kubew2
  Normal  Pulled     16m   kubelet, kubew2    Container image "mysql:5.6" already present on machine
  Normal  Created    16m   kubelet, kubew2    Created container
  Normal  Started    16m   kubelet, kubew2    Started container

Here are the PV and PVC status -- It shows that only mysql has bound but wordpress is not.

kubi@kubem:~/wordpress2$ kubectl get pvc,pv
NAME                                   STATUS    VOLUME           CAPACITY   ACCESS MODES   STORAGECLASS   AGE
persistentvolumeclaim/mysql-lv-claim   Bound     local-volume-1   8Gi        RWO                           27m
persistentvolumeclaim/wp-lv-claim      Pending                                                             24m

NAME                              CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS     CLAIM                    STORAGECLASS   REASON   AGE
persistentvolume/local-volume-1   8Gi        RWO            Retain           Bound      default/mysql-lv-claim                           27m
persistentvolume/local-volume-2   8Gi        RWO            Retain           Released   default/wp-lv-claim                              27m

Please suggest how to investigate the issue further, so that I can get the wordpress running on my cluster.

Cluster specification : 1 Master + 2 Slaves on Ubuntu VMs

Thanks

-- Pert8S
docker
kubectl
kubernetes
mysql
wordpress

0 Answers