这是我的configmap.yaml文件：
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql
labels:
app: mysql
app.kubernetes.io/name: mysql
data:
primary.cnf: |
# Apply this config only on the primary.
[mysqld]
log-bin
replica.cnf: |
# Apply this config only on replicas.
[mysqld]
super-read-only
文件内容如下mysql-depl.yaml：
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: mysql
spec:
selector:
matchLabels:
app: mysql
app.kubernetes.io/name: mysql
serviceName: mysql
replicas: 3
template:
metadata:
labels:
app: mysql
app.kubernetes.io/name: mysql
spec:
initContainers:
- name: init-mysql
image: mysql
command:
- bash
- "-c"
- |
set -ex
# Generate mysql server-id from pod ordinal index.
[[ $HOSTNAME =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
echo [mysqld] > /mnt/conf.d/server-id.cnf
# Add an offset to avoid reserved server-id=0 value.
echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf
# Copy appropriate conf.d files from config-map to emptyDir.
if [[ $ordinal -eq 0 ]]; then
cp /mnt/config-map/primary.cnf /mnt/conf.d/
else
cp /mnt/config-map/replica.cnf /mnt/conf.d/
fi
volumeMounts:
- name: conf
mountPath: /mnt/conf.d
- name: config-map
mountPath: /mnt/config-map
- name: clone-mysql
image: gcr.io/google-samples/xtrabackup:1.0
command:
- bash
- "-c"
- |
set -ex
# Skip the clone if data already exists.
[[ -d /var/lib/mysql/mysql ]] && exit 0
# Skip the clone on primary (ordinal index 0).
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
[[ $ordinal -eq 0 ]] && exit 0
# Clone data from previous peer.
ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql
# Prepare the backup.
xtrabackup --prepare --target-dir=/var/lib/mysql
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
containers:
- name: mysql
image: mysql:5.7
env:
- name: MYSQL_ALLOW_EMPTY_PASSWORD
value: "1"
ports:
- name: mysql
containerPort: 3306
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
resources:
requests:
cpu: 500m
memory: 1Gi
livenessProbe:
exec:
command: ["mysqladmin", "ping"]
initialDelaySeconds: 30
periodSeconds: 10
timeoutSeconds: 5
readinessProbe:
exec:
# Check we can execute queries over TCP (skip-networking is off).
command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"]
initialDelaySeconds: 5
periodSeconds: 2
timeoutSeconds: 1
- name: xtrabackup
image: gcr.io/google-samples/xtrabackup:1.0
ports:
- name: xtrabackup
containerPort: 3307
command:
- bash
- "-c"
- |
set -ex
cd /var/lib/mysql
# Determine binlog position of cloned data, if any.
if [[ -f xtrabackup_slave_info && "x$(<xtrabackup_slave_info)" != "x" ]]; then
# XtraBackup already generated a partial "CHANGE MASTER TO" query
# because we're cloning from an existing replica. (Need to remove the tailing semicolon!)
cat xtrabackup_slave_info | sed -E 's/;$//g' > change_master_to.sql.in
# Ignore xtrabackup_binlog_info in this case (it's useless).
rm -f xtrabackup_slave_info xtrabackup_binlog_info
elif [[ -f xtrabackup_binlog_info ]]; then
# We're cloning directly from primary. Parse binlog position.
[[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1
rm -f xtrabackup_binlog_info xtrabackup_slave_info
echo "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH[1]}',\
MASTER_LOG_POS=${BASH_REMATCH[2]}" > change_master_to.sql.in
fi
# Check if we need to complete a clone by starting replication.
if [[ -f change_master_to.sql.in ]]; then
echo "Waiting for mysqld to be ready (accepting connections)"
until mysql -h 127.0.0.1 -e "SELECT 1"; do sleep 1; done
echo "Initializing replication from clone position"
mysql -h 127.0.0.1 \
-e "$(<change_master_to.sql.in), \
MASTER_HOST='mysql-0.mysql', \
MASTER_USER='root', \
MASTER_PASSWORD='', \
MASTER_CONNECT_RETRY=10; \
START SLAVE;" || exit 1
# In case of container restart, attempt this at-most-once.
mv change_master_to.sql.in change_master_to.sql.orig
fi
# Start a server to send backups when requested by peers.
exec ncat --listen --keep-open --send-only --max-conns=1 3307 -c \
"xtrabackup --backup --slave-info --stream=xbstream --host=127.0.0.1 --user=root"
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
resources:
requests:
cpu: 100m
memory: 100Mi
volumes:
- name: conf
emptyDir: {}
- name: config-map
configMap:
name: mysql
volumeClaimTemplates:
- metadata:
name: data
spec:
accessModes: ["ReadWriteOnce"]
resources:
requests:
storage: 10Gi
---
# Headless service for stable DNS entries of StatefulSet members.
apiVersion: v1
kind: Service
metadata:
name: mysql
labels:
app: mysql
app.kubernetes.io/name: mysql
spec:
ports:
- name: mysql
port: 3306
clusterIP: None
selector:
app: mysql
---
# Client service for connecting to any MySQL instance for reads.
# For writes, you must instead connect to the primary: mysql-0.mysql.
apiVersion: v1
kind: Service
metadata:
name: mysql-read
labels:
app: mysql
app.kubernetes.io/name: mysql
readonly: "true"
spec:
ports:
- name: mysql
port: 3306
selector:
app: mysql
当我成功应用这两个文件并检查 pod 时，kubectl get pods我看到的结果如下：
NAME READY STATUS RESTARTS AGE
mysql-0 1/2 CrashLoopBackOff 9 (52s ago) 20m
我Kind在本地 Ubuntu 22.04 机器上使用以下配置的集群：
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
- role: worker
结果describe pod mysql-0：
Name: mysql-0
Namespace: default
Priority: 0
Service Account: default
Node: kind-worker/172.18.0.3
Start Time: Fri, 30 Dec 2022 11:34:11 -0800
Labels: app=mysql
app.kubernetes.io/name=mysql
controller-revision-hash=mysql-7d8d6f4696
statefulset.kubernetes.io/pod-name=mysql-0
Annotations: <none>
Status: Running
IP: 10.244.1.3
IPs:
IP: 10.244.1.3
Controlled By: StatefulSet/mysql
Init Containers:
init-mysql:
Container ID: containerd://0cb850e677789c328b394905d40eee8cab539847fab784162b25f05dbbce0d31
Image: mysql
Image ID: docker.io/library/mysql@sha256:3d7ae561cf6095f6aca8eb7830e1d14734227b1fb4748092f2be2cfbccf7d614
Port: <none>
Host Port: <none>
Command:
bash
-c
set -ex
# Generate mysql server-id from pod ordinal index.
[[ $HOSTNAME =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
echo [mysqld] > /mnt/conf.d/server-id.cnf
# Add an offset to avoid reserved server-id=0 value.
echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf
# Copy appropriate conf.d files from config-map to emptyDir.
if [[ $ordinal -eq 0 ]]; then
cp /mnt/config-map/primary.cnf /mnt/conf.d/
else
cp /mnt/config-map/replica.cnf /mnt/conf.d/
fi
State: Terminated
Reason: Completed
Exit Code: 0
Started: Fri, 30 Dec 2022 11:34:45 -0800
Finished: Fri, 30 Dec 2022 11:34:45 -0800
Ready: True
Restart Count: 0
Environment: <none>
Mounts:
/mnt/conf.d from conf (rw)
/mnt/config-map from config-map (rw)
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-r4j87 (ro)
clone-mysql:
Container ID: containerd://0b0ffb57fca6234b09b033963850a7cc7acdc4150b85652f3eb195aef970ca7f
Image: gcr.io/google-samples/xtrabackup:1.0
Image ID: sha256:cee14c121daad572f219c0128ea1fdff4b81e7faf714c78b853427af3bda1cf7
Port: <none>
Host Port: <none>
Command:
bash
-c
set -ex
# Skip the clone if data already exists.
[[ -d /var/lib/mysql/mysql ]] && exit 0
# Skip the clone on primary (ordinal index 0).
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
[[ $ordinal -eq 0 ]] && exit 0
# Clone data from previous peer.
ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql
# Prepare the backup.
xtrabackup --prepare --target-dir=/var/lib/mysql
State: Terminated
Reason: Completed
Exit Code: 0
Started: Fri, 30 Dec 2022 11:35:13 -0800
Finished: Fri, 30 Dec 2022 11:35:13 -0800
Ready: True
Restart Count: 0
Environment: <none>
Mounts:
/etc/mysql/conf.d from conf (rw)
/var/lib/mysql from data (rw,path="mysql")
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-r4j87 (ro)
Containers:
mysql:
Container ID: containerd://f228587f532100ac6a1685b935877dcfdeb304c30d89542261976f243cbd936b
Image: mysql
Image ID: docker.io/library/mysql@sha256:3d7ae561cf6095f6aca8eb7830e1d14734227b1fb4748092f2be2cfbccf7d614
Port: 3306/TCP
Host Port: 0/TCP
State: Waiting
Reason: CrashLoopBackOff
Last State: Terminated
Reason: Error
Exit Code: 1
Started: Fri, 30 Dec 2022 15:18:57 -0800
Finished: Fri, 30 Dec 2022 15:18:58 -0800
Ready: False
Restart Count: 47
Requests:
cpu: 500m
memory: 1Gi
Liveness: exec [mysqladmin ping] delay=30s timeout=5s period=10s #success=1 #failure=3
Readiness: exec [mysql -h 127.0.0.1 -e SELECT 1] delay=5s timeout=1s period=2s #success=1 #failure=3
Environment:
MYSQL_ALLOW_EMPTY_PASSWORD: 1
Mounts:
/etc/mysql/conf.d from conf (rw)
/var/lib/mysql from data (rw,path="mysql")
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-r4j87 (ro)
xtrabackup:
Container ID: containerd://9c4b58c109e500e1cc2c68d3f1830cc065e850713b01a724d5a293a21fc21bb5
Image: gcr.io/google-samples/xtrabackup:1.0
Image ID: sha256:cee14c121daad572f219c0128ea1fdff4b81e7faf714c78b853427af3bda1cf7
Port: 3307/TCP
Host Port: 0/TCP
Command:
bash
-c
set -ex
cd /var/lib/mysql
# Determine binlog position of cloned data, if any.
if [[ -f xtrabackup_slave_info && "x$(<xtrabackup_slave_info)" != "x" ]]; then
# XtraBackup already generated a partial "CHANGE MASTER TO" query
# because we're cloning from an existing replica. (Need to remove the tailing semicolon!)
cat xtrabackup_slave_info | sed -E 's/;$//g' > change_master_to.sql.in
# Ignore xtrabackup_binlog_info in this case (it's useless).
rm -f xtrabackup_slave_info xtrabackup_binlog_info
elif [[ -f xtrabackup_binlog_info ]]; then
# We're cloning directly from primary. Parse binlog position.
[[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1
rm -f xtrabackup_binlog_info xtrabackup_slave_info
echo "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH[1]}',\
MASTER_LOG_POS=${BASH_REMATCH[2]}" > change_master_to.sql.in
fi
# Check if we need to complete a clone by starting replication.
if [[ -f change_master_to.sql.in ]]; then
echo "Waiting for mysqld to be ready (accepting connections)"
until mysql -h 127.0.0.1 -e "SELECT 1"; do sleep 1; done
echo "Initializing replication from clone position"
mysql -h 127.0.0.1 \
-e "$(<change_master_to.sql.in), \
MASTER_HOST='mysql-0.mysql', \
MASTER_USER='root', \
MASTER_PASSWORD='', \
MASTER_CONNECT_RETRY=10; \
START SLAVE;" || exit 1
# In case of container restart, attempt this at-most-once.
mv change_master_to.sql.in change_master_to.sql.orig
fi
# Start a server to send backups when requested by peers.
exec ncat --listen --keep-open --send-only --max-conns=1 3307 -c \
"xtrabackup --backup --slave-info --stream=xbstream --host=127.0.0.1 --user=root"
State: Running
Started: Fri, 30 Dec 2022 11:35:46 -0800
Ready: True
Restart Count: 0
Requests:
cpu: 100m
memory: 100Mi
Environment: <none>
Mounts:
/etc/mysql/conf.d from conf (rw)
/var/lib/mysql from data (rw,path="mysql")
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-r4j87 (ro)
Conditions:
Type Status
Initialized True
Ready False
ContainersReady False
PodScheduled True
Volumes:
data:
Type: PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
ClaimName: data-mysql-0
ReadOnly: false
conf:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
config-map:
Type: ConfigMap (a volume populated by a ConfigMap)
Name: mysql
Optional: false
kube-api-access-r4j87:
Type: Projected (a volume that contains injected data from multiple sources)
TokenExpirationSeconds: 3607
ConfigMapName: kube-root-ca.crt
ConfigMapOptional: <nil>
DownwardAPI: true
QoS Class: Burstable
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning BackOff 65s (x987 over 3h43m) kubelet Back-off restarting failed container
附言：我也想知道为什么会显示READY 1/2？之前我以同样的方式部署cassandra，但还是显示READY 1/1，在 1 节点机器上也一样mysql。这里还添加了什么？
编辑：这是结果kubectl logs mysql-0 -c mysql：
2022-12-31 00:48:16+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.31-1.el8 started.
2022-12-31 00:48:16+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2022-12-31 00:48:16+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.31-1.el8 started.
2022-12-31T00:48:17.443527Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.31) starting as process 1
2022-12-31T00:48:17.443610Z 0 [ERROR] [MY-010338] [Server] Can't find error-message file '/usr/share/mysql-8.0/errmsg.sys'. Check error-message file location and 'lc-messages-dir' configuration directive.
2022-12-31T00:48:17.507830Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2022-12-31T00:48:17.637835Z 1 [ERROR] [MY-012960] [InnoDB] Cannot create redo log files because data files are corrupt or the database was not shut down cleanly after creating the data files.
2022-12-31T00:48:18.122850Z 1 [ERROR] [MY-010334] [Server] Failed to initialize DD Storage Engine
2022-12-31T00:48:18.123114Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2022-12-31T00:48:18.123131Z 0 [ERROR] [MY-010119] [Server] Aborting
2022-12-31T00:48:18.123592Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.31) MySQL Community Server - GPL.
答案1
这是给你的一半答案：
PS：我也想知道为什么它显示READY 1/2？
输出READY x/y会告诉您 pod 中有多少个容器处于“就绪”状态。在 Cassandra 部署中，您只有一个容器。在 MySQL 部署中，您有两个容器：
mysql根据镜像命名的容器mysql:5.7xtrabackup根据镜像命名的容器gcr.io/google-samples/xtrabackup:1.0
容器xtrabackup正在运行但是mysql容器出现故障，所以你看到了READY 1/2。