差異處

這裏顯示兩個版本的差異處。

--- tech:kubectl [2021/04/17 12:54] – [顯示 K8s 內的 POD 清單] jonathan
+++ tech:kubectl [2023/02/04 16:47] (目前版本) – jonathan
@@ 行 13: / 行 13: @@
 scheduler            Healthy   ok
 etcd-0               Healthy   {"health":"true"}
+</cli>
+===== 讀取 K8s Cluster Name 的方式 =====
+  * 參考 - https://stackoverflow.com/questions/38242062/how-to-get-kubernetes-cluster-name-from-k8s-api
+  * 方法1 <cli>kubectl config current-context</cli>結果:<cli>
+rkeuser@devops2:~$ kubectl config current-context
+iiidevops-k8s
+</cli>
+  * 方法2 <cli>kubectl config view</cli>結果:<cli>
+rkeuser@devops2:~$ kubectl config view
+apiVersion: v1
+clusters:
+- cluster:
+    certificate-authority-data: DATA+OMITTED
+    server: https://172.16.0.172:6443
+  name: iiidevops-k8s
+contexts:
+- context:
+    cluster: iiidevops-k8s
+    user: kube-admin-iiidevops-k8s
+  name: iiidevops-k8s
+current-context: iiidevops-k8s
+kind: Config
+preferences: {}
+users:
+- name: kube-admin-iiidevops-k8s
+  user:
+    client-certificate-data: REDACTED
+    client-key-data: REDACTED
 </cli>
@@ 行 156: / 行 185: @@
 namespace "iii-devops-toolchain" deleted
 </cli>
+===== 讀取 Secret 的內容 =====
+  * <cli>kubectl get secret [secret_name]</cli> Exp.<cli>
+rkeuser@dev4-86:~$ kubectl get secret
+NAME                                    TYPE                                  DATA   AGE
+default-token-pssx6                     kubernetes.io/service-account-token   3      21d
+gitlab                                  Opaque                                1      21d
+harbor                                  Opaque                                1      21d
+harbor-harbor-clair                     Opaque                                3      21d
+harbor-harbor-clair-internal-tls        kubernetes.io/tls                     3      21d
+harbor-harbor-core                      Opaque                                8      21d
+:
+</cli>
+  * 顯示 secret 的內容, 有定義那些 key<cli>kubectl describe secret [secret_name]</cli> Exp.<cli>
+rkeuser@dev4-86:~$ kubectl describe secret harbor
+Name:         harbor
+Namespace:    default
+Labels:       <none>
+Annotations:  field.cattle.io/creatorId: user-jwvbx
+              field.cattle.io/projectId: local:p-rhflt
+              lifecycle.cattle.io/create.secretsController_local: true
+              secret.user.cattle.io/secret: true
+Type:  Opaque
+Data
+====
+harbor-local:  25 bytes
+</cli>
+  * 顯示 secret key 的 value 編碼內容<cli>
+kubectl get secrets/<secret_name> --template={{.data.<key>}}
+</cli> Exp.<cli>
+kubectl get secrets/harbor --template={{.data.harbor-local}}
+</cli>
+<WRAP center round tip 60%>
+** 如果要直接解碼可使用 base64 -d 的方式處理** Exp. <cli>
+kubectl get secrets/harbor --template={{.data.harbor-local}} | base64 -d
+</cli>
+</WRAP>
+===== 讀取 kubelet 內的 pod 目錄編號 =====
+  * 實際 pod 的檔案存在 node 內的 /var/lib/kubelet/pods 內, 可透過以下語法獲知 pod 的目錄編號<cli>
+kubectl get pods -A -o custom-columns=NodeName:.spec.nodeName,PodName:.metadata.name,PodUID:.metadata.uid
+</cli>
+    * ++看實際範例|<cli>
+rkeuser@demo-77:~$ kubectl get pods -A -o custom-columns=NodeName:.spec.nodeName,PodName:.metadata.name,PodUID:.metadata.uid
+NodeName     PodName                                                           PodUID
+.20.0.79   a1-master-db-dpy-79bc97bf96-xmqxw                                 34dad11c-7f38-44c1-b1b0-e06d760d2a7e
+.20.0.79   a1-master-db-gui-7cc89bcb59-vlhtz                                 9cc444c9-3986-4ba2-a535-9f44f6bb10cf
+.20.0.79   a1-master-sq-4-wkv2l                                              94dc6771-bea0-46bd-a0ec-0128e7c5c16d
+.20.0.78   apeg-python-flask-master-serv-dpy-86b655666-9ngdf                 0903dcd1-c1f5-4704-b8ba-7991d11e882d
+.20.0.78   aptgit-220209-master-db-dpy-5f7986d9c-wvv2c                       7209d08f-d0b8-428d-922c-87b3f6fe5787
+.20.0.77   aptgit-220209-master-db-gui-67bbbf77cb-h9qxh                      498451f9-fa3a-4fa6-bd2c-dd1ae1d9a3b7
+.20.0.79   aptgit-220209-master-db-gui-67bbbf77cb-t79qf                      ba6e310c-a106-426e-910a-290e836c40a9
+.20.0.78   aptgit-220209-master-serv-dpy-5cf7cccd4d-66vns                    522553e2-3323-44cb-bb02-3995d625c033
+.20.0.77   aptgit-220209-master-serv-dpy-5cf7cccd4d-k2jl8                    f8a147db-3eee-4d40-b051-f6b00bc0a644
+:
+</cli> 直接看 aptgit-220209-master-db-gui-67bbbf77cb-h9qxh -> 498451f9-fa3a-4fa6-bd2c-dd1ae1d9a3b7 這個 POD 的檔案<cli>
+rkeuser@demo-77:~$ sudo ls -lRt /var/lib/kubelet/pods/498451f9-fa3a-4fa6-bd2c-dd1ae1d9a3b7
+/var/lib/kubelet/pods/498451f9-fa3a-4fa6-bd2c-dd1ae1d9a3b7:
+total 16
+-rw-r--r-- 1 root root  241 Jan  7 09:04 etc-hosts
+drwxr-x--- 3 root root 4096 Jun 25  2022 containers
+drwxr-x--- 3 root root 4096 Jun 25  2022 plugins
+drwxr-x--- 3 root root 4096 Jun 25  2022 volumes
+/var/lib/kubelet/pods/498451f9-fa3a-4fa6-bd2c-dd1ae1d9a3b7/containers:
+total 4
+drwxr-x--- 2 root root 4096 Jan  7 09:04 mariadb-gui
+/var/lib/kubelet/pods/498451f9-fa3a-4fa6-bd2c-dd1ae1d9a3b7/containers/mariadb-gui:
+total 0
+-rw-rw-rw- 1 root root 0 Jan  7 09:04 832a851d
+-rw-rw-rw- 1 root root 0 Nov 19 09:26 d65ebd13
+-rw-rw-rw- 1 root root 0 Oct 15 06:39 d516d827
+-rw-rw-rw- 1 root root 0 Oct 14 19:16 ea72f4fc
+-rw-rw-rw- 1 root root 0 Sep 17 11:11 94285167
+-rw-rw-rw- 1 root root 0 Aug 28 18:14 edc19f39
+-rw-rw-rw- 1 root root 0 Jul 30  2022 cbf94e15
+-rw-rw-rw- 1 root root 0 Jul 14  2022 f3f9f859
+-rw-rw-rw- 1 root root 0 Jun 25  2022 46143b63
+/var/lib/kubelet/pods/498451f9-fa3a-4fa6-bd2c-dd1ae1d9a3b7/plugins:
+total 4
+drwxr-x--- 2 root root 4096 Jan 30 07:48 kubernetes.io~empty-dir
+/var/lib/kubelet/pods/498451f9-fa3a-4fa6-bd2c-dd1ae1d9a3b7/plugins/kubernetes.io~empty-dir:
+total 0
+/var/lib/kubelet/pods/498451f9-fa3a-4fa6-bd2c-dd1ae1d9a3b7/volumes:
+total 4
+drwxr-xr-x 2 root root 4096 Jan 30 07:48 kubernetes.io~secret
+/var/lib/kubelet/pods/498451f9-fa3a-4fa6-bd2c-dd1ae1d9a3b7/volumes/kubernetes.io~secret:
+total 0
+rkeuser@demo-77:~$
+</cli>++
 {{tag>k8s iiidevops kubectl}}