Merge branch 'master' into patch-1

2021-04-18 23:39:09 +02:00 · 2021-04-18 23:39:09 +02:00 · 7b3f8ed6ce
parent b62a3e49fe 34821eb496
commit 7b3f8ed6ce
14 changed files with 78 additions and 67 deletions
--- a/deployments/coredns.yaml
+++ b/deployments/coredns.yaml
@ -62,7 +62,7 @@ data:
        loadbalance
    }
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
  name: coredns
--- a/docs/01-prerequisites.md
+++ b/docs/01-prerequisites.md
@ -2,7 +2,7 @@

 ## VM Hardware Requirements

-8 GB of RAM (Preferebly 16 GB)
+8 GB of RAM (Preferably 16 GB)
 50 GB Disk space

 ## Virtual Box
--- a/docs/02-compute-resources.md
+++ b/docs/02-compute-resources.md
@ -73,7 +73,7 @@ Vagrant generates a private key for each of these VMs. It is placed under the .v

 ## Troubleshooting Tips

-If any of the VMs failed to provision, or is not configured correct, delete the vm using the command:
+1. If any of the VMs failed to provision, or is not configured correct, delete the vm using the command:

 `vagrant destroy <vm>`

@ -97,3 +97,11 @@ In such cases delete the VM, then delete the VM folder and then re-provision
 `rmdir "<path-to-vm-folder>\kubernetes-ha-worker-2"`

 `vagrant up`
+
+2. When you try "sysctl net.bridge.bridge-nf-call-iptables=1", it would sometimes return "sysctl: cannot stat /proc/sys/net/bridge/bridge-nf-call-iptables: No such file or directory" error. The below would resolve the issue.
+
+`modprobe br_netfilter`
+
+`sysctl -p /etc/sysctl.conf`
+
+`net.bridge.bridge-nf-call-iptables=1`
--- a/docs/05-kubernetes-configuration-files.md
+++ b/docs/05-kubernetes-configuration-files.md
@ -45,10 +45,9 @@ Results:

 ```
 kube-proxy.kubeconfig
-
+```

 Reference docs for kube-proxy [here](https://kubernetes.io/docs/reference/command-line-tools-reference/kube-proxy/)
-```

 ### The kube-controller-manager Kubernetes Configuration File

--- a/docs/07-bootstrapping-etcd.md
+++ b/docs/07-bootstrapping-etcd.md
@ -8,7 +8,7 @@ The commands in this lab must be run on each controller instance: `master-1`, an

 ### Running commands in parallel with tmux

-[tmux](https://github.com/tmux/tmux/wiki) can be used to run commands on multiple compute instances at the same time. See the [Running commands in parallel with tmux](01-prerequisites.md#running-commands-in-parallel-with-tmux) section in the Prerequisites lab.
+[tmux](https://github.com/tmux/tmux/wiki) can be used to run commands on multiple compute instances at the same time.

 ## Bootstrapping an etcd Cluster Member

--- a/docs/08-bootstrapping-kubernetes-controllers.md
+++ b/docs/08-bootstrapping-kubernetes-controllers.md
@ -78,7 +78,7 @@ Documentation=https://github.com/kubernetes/kubernetes
 ExecStart=/usr/local/bin/kube-apiserver \\
  --advertise-address=${INTERNAL_IP} \\
  --allow-privileged=true \\
-  --apiserver-count=3 \\
+  --apiserver-count=2 \\
  --audit-log-maxage=30 \\
  --audit-log-maxbackup=3 \\
  --audit-log-maxsize=100 \\
@ -99,7 +99,7 @@ ExecStart=/usr/local/bin/kube-apiserver \\
  --kubelet-client-certificate=/var/lib/kubernetes/kube-apiserver.crt \\
  --kubelet-client-key=/var/lib/kubernetes/kube-apiserver.key \\
  --kubelet-https=true \\
-  --runtime-config=api/all \\
+  --runtime-config=api/all=true \\
  --service-account-key-file=/var/lib/kubernetes/service-account.crt \\
  --service-cluster-ip-range=10.96.0.0/24 \\
  --service-node-port-range=30000-32767 \\
--- a/docs/10-tls-bootstrapping-kubernetes-workers.md
+++ b/docs/10-tls-bootstrapping-kubernetes-workers.md
@ -14,7 +14,11 @@ This is not a practical approach when you have 1000s of nodes in the cluster, an
 - The Nodes can retrieve the signed certificate from the Kubernetes CA
 - The Nodes can generate a kube-config file using this certificate by themselves
 - The Nodes can start and join the cluster by themselves
- The Nodes can renew certificates when they expire by themselves
+- The Nodes can request new certificates via a CSR, but the CSR must be manually approved by a cluster administrator
+
+In Kubernetes 1.11 a patch was merged to require administrator or Controller approval of node serving CSRs for security reasons.
+
+Reference: https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet-tls-bootstrapping/#certificate-rotation

 So let's get started!

@ -86,7 +90,7 @@ For the workers(kubelet) to access the Certificates API, they need to authentica

 Bootstrap Tokens take the form of a 6 character token id followed by 16 character token secret separated by a dot. Eg: abcdef.0123456789abcdef. More formally, they must match the regular expression [a-z0-9]{6}\.[a-z0-9]{16}

-Bootstrap Tokens are created as a secret in the kube-system namespace on the master node.
+

 ```
 master-1$ cat > bootstrap-token-07401b.yaml <<EOF
@ -311,7 +315,6 @@ ExecStart=/usr/local/bin/kubelet \\
  --kubeconfig=/var/lib/kubelet/kubeconfig \\
  --cert-dir=/var/lib/kubelet/pki/ \\
  --rotate-certificates=true \\
-  --rotate-server-certificates=true \\
  --network-plugin=cni \\
  --register-node=true \\
  --v=2
@ -327,7 +330,6 @@ Things to note here:
 - **bootstrap-kubeconfig**: Location of the bootstrap-kubeconfig file.
 - **cert-dir**: The directory where the generated certificates are stored.
 - **rotate-certificates**: Rotates client certificates when they expire.
- **rotate-server-certificates**: Requests for server certificates on bootstrap and rotates them when they expire.

 ## Step 7 Configure the Kubernetes Proxy

@ -397,6 +399,8 @@ Approve

 `master-1$ kubectl certificate approve csr-95bv6`

+Note: In the event your cluster persists for longer than 365 days, you will need to manually approve the replacement CSR.
+
 Reference: https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet-tls-bootstrapping/#kubectl-approval

 ## Verification
--- a/docs/11-configuring-kubectl.md
+++ b/docs/11-configuring-kubectl.md
@ -29,9 +29,9 @@ Generate a kubeconfig file suitable for authenticating as the `admin` user:

  kubectl config use-context kubernetes-the-hard-way
 }
+```

 Reference doc for kubectl config [here](https://kubernetes.io/docs/tasks/access-application-cluster/configure-access-multiple-clusters/)
-```

 ## Verification

--- a/docs/13-kube-apiserver-to-kubelet.md
+++ b/docs/13-kube-apiserver-to-kubelet.md
@ -53,6 +53,6 @@ subjects:
    name: kube-apiserver
 EOF
 ```
-Reference: https://v1-12.docs.kubernetes.io/docs/reference/access-authn-authz/rbac/#rolebinding-and-clusterrolebinding
+Reference: https://kubernetes.io/docs/reference/access-authn-authz/rbac/#rolebinding-and-clusterrolebinding

 Next: [DNS Addon](14-dns-addon.md)
--- a/docs/16-e2e-tests.md
+++ b/docs/16-e2e-tests.md
@ -3,9 +3,9 @@
 Install Go

 ```
-wget https://dl.google.com/go/go1.12.1.linux-amd64.tar.gz
+wget https://dl.google.com/go/go1.15.linux-amd64.tar.gz

-sudo tar -C /usr/local -xzf go1.12.1.linux-amd64.tar.gz
+sudo tar -C /usr/local -xzf go1.15.linux-amd64.tar.gz
 export GOPATH="/home/vagrant/go"
 export PATH=$PATH:/usr/local/go/bin:$GOPATH/bin
 ```
--- a/docs/17-extra-dynamic-kubelet-configuration.md
+++ b/docs/17-extra-dynamic-kubelet-configuration.md
@ -11,9 +11,18 @@ NODE_NAME="worker-1"; NODE_NAME="worker-1"; curl -sSL "https://localhost:6443/ap
 kubectl -n kube-system create configmap nodes-config --from-file=kubelet=kubelet_configz_${NODE_NAME} --append-hash -o yaml
 ```

-Edit node to use the dynamically created configuration
+Edit `worker-1` node to use the dynamically created configuration
 ```
-kubectl edit worker-2
+master-1# kubectl edit node worker-1
+```
+
+Add the following YAML bit under `spec`:
+```
+configSource:
+    configMap:
+        name: CONFIG_MAP_NAME # replace CONFIG_MAP_NAME with the name of the ConfigMap
+        namespace: kube-system
+        kubeletConfigKey: kubelet
 ```

 Configure Kubelet Service
@ -45,3 +54,5 @@ RestartSec=5
 WantedBy=multi-user.target
 EOF
 ```
+
+Reference: https://kubernetes.io/docs/tasks/administer-cluster/reconfigure-kubelet/
--- a/practice-questions-answers/cluster-maintenance/backup-etcd/etcd-backup-and-restore.md
+++ b/practice-questions-answers/cluster-maintenance/backup-etcd/etcd-backup-and-restore.md
@ -5,7 +5,7 @@
 Reference: https://github.com/etcd-io/etcd/releases

 ```
-ETCD_VER=v3.3.13
+ETCD_VER=v3.4.9

 # choose either URL
 GOOGLE_URL=https://storage.googleapis.com/etcd
@ -30,9 +30,15 @@ mv /tmp/etcd-download-test/etcdctl /usr/bin
 ```
 ETCDCTL_API=3 etcdctl --endpoints=https://[127.0.0.1]:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt \
     --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key \
-     snapshot save /tmp/snapshot-pre-boot.db
+     snapshot save /opt/snapshot-pre-boot.db
 ```

+Note: In this case, the **ETCD** is running on the same server where we are running the commands (which is the *controlplane* node). As a result, the **--endpoint** argument is optional and can be ignored. 
+
+The options **--cert, --cacert and --key** are mandatory to authenticate to the ETCD server to take the backup.
+
+If you want to take a backup of the ETCD service running on a different machine, you will have to provide the correct endpoint to that server (which is the IP Address and port of the etcd server with the **--endpoint** argument)
+
 # -----------------------------
 # Disaster Happens
 # -----------------------------
@ -40,51 +46,34 @@ ETCDCTL_API=3 etcdctl --endpoints=https://[127.0.0.1]:2379 --cacert=/etc/kuberne
 # 3. Restore ETCD Snapshot to a new folder

 ```
-ETCDCTL_API=3 etcdctl --endpoints=https://[127.0.0.1]:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt \
-     --name=master \
-     --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key \
-     --data-dir /var/lib/etcd-from-backup \
-     --initial-cluster=master=https://127.0.0.1:2380 \
-     --initial-cluster-token=etcd-cluster-1 \
-     --initial-advertise-peer-urls=https://127.0.0.1:2380 \
-     snapshot restore /tmp/snapshot-pre-boot.db
+ETCDCTL_API=3 etcdctl  --data-dir /var/lib/etcd-from-backup \
+     snapshot restore /opt/snapshot-pre-boot.db
 ```

+Note: In this case, we are restoring the snapshot to a different directory but in the same server where we took the backup (**the controlplane node)**
+As a result, the only required option for the restore command is the **--data-dir**.  
+
 # 4. Modify /etc/kubernetes/manifests/etcd.yaml

-Update ETCD POD to use the new data directory and cluster token by modifying the pod definition file at `/etc/kubernetes/manifests/etcd.yaml`. When this file is updated, the ETCD pod is automatically re-created as this is a static pod placed under the `/etc/kubernetes/manifests` directory.
-
-Update --data-dir to use new target location
+We have now restored the etcd snapshot  to a new path on the controlplane - **/var/lib/etcd-from-backup**, so, the only change to be made in the YAML file, is to change the hostPath for the volume called **etcd-data** from old directory (/var/lib/etcd) to the new directory **/var/lib/etcd-from-backup**.

 ```
--data-dir=/var/lib/etcd-from-backup
-```
-
-Update new initial-cluster-token to specify new cluster
-
-```
--initial-cluster-token=etcd-cluster-1
-```
-
-Update volumes and volume mounts to point to new path
-
-```
-    volumeMounts:
-    - mountPath: /var/lib/etcd-from-backup
-      name: etcd-data
-    - mountPath: /etc/kubernetes/pki/etcd
-      name: etcd-certs
-  hostNetwork: true
-  priorityClassName: system-cluster-critical
  volumes:
  - hostPath:
      path: /var/lib/etcd-from-backup
      type: DirectoryOrCreate
    name: etcd-data
-  - hostPath:
-      path: /etc/kubernetes/pki/etcd
-      type: DirectoryOrCreate
-    name: etcd-certs
 ```
+With this change, /var/lib/etcd on the **container** points to /var/lib/etcd-from-backup on the **controlplane** (which is what we want)

-> Note: You don't really need to update data directory and volumeMounts.mountPath path above. You could simply just update the hostPath.path in the volumes section to point to the new directory. But if you are not working with a kubeadm deployed cluster, then you might have to update the data directory. That's why I left it as is. 
+
+When this file is updated, the ETCD pod is automatically re-created as this is a static pod placed under the `/etc/kubernetes/manifests` directory.
+
+
+> Note: as the ETCD pod has changed it will automatically restart, and also kube-controller-manager and kube-scheduler. Wait 1-2 to mins for this pods to restart. You can make a `watch "docker ps | grep etcd"` to see when the ETCD pod is restarted.
+
+> Note2: If the etcd pod is not getting `Ready 1/1`, then restart it by `kubectl delete pod -n kube-system etcd-controlplane` and wait 1 minute.
+
+> Note3: This is the simplest way to make sure that ETCD uses the restored data after the ETCD pod is recreated. You **don't** have to change anything else.
+  
+  **If** you do change **--data-dir** to **/var/lib/etcd-from-backup** in the YAML file, make sure that the **volumeMounts** for **etcd-data** is updated as well, with the mountPath pointing to /var/lib/etcd-from-backup (**THIS COMPLETE STEP IS OPTIONAL AND NEED NOT BE DONE FOR COMPLETING THE RESTORE**)
--- a/tools/kubernetes-certs-checker.xlsx
+++ b/tools/kubernetes-certs-checker.xlsx
--- a/vagrant/ubuntu/cert_verify.sh
+++ b/vagrant/ubuntu/cert_verify.sh
@ -310,8 +310,8 @@ check_cert_kpkubeconfig()
        elif [ -f $KPKUBECONFIG ]
            then
                printf "${NC}kube-proxy kubeconfig file found, verifying the authenticity\n"
-                KPKUBECONFIG_SUBJECT=$(cat $KPKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 --text | grep "Subject: CN" | tr -d " ")
-                KPKUBECONFIG_ISSUER=$(cat $KPKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 --text | grep "Issuer: CN" | tr -d " ")
+                KPKUBECONFIG_SUBJECT=$(cat $KPKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -text | grep "Subject: CN" | tr -d " ")
+                KPKUBECONFIG_ISSUER=$(cat $KPKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -text | grep "Issuer: CN" | tr -d " ")
                KPKUBECONFIG_CERT_MD5=$(cat $KPKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -noout | openssl md5 | awk '{print $2}')
                KPKUBECONFIG_KEY_MD5=$(cat $KPKUBECONFIG | grep "client-key-data" | awk '{print $2}' | base64 --decode | openssl rsa -noout | openssl md5 | awk '{print $2}')
                KPKUBECONFIG_SERVER=$(cat $KPKUBECONFIG | grep "server:"| awk '{print $2}')
@ -337,8 +337,8 @@ check_cert_kcmkubeconfig()
        elif [ -f $KCMKUBECONFIG ]
            then
                printf "${NC}kube-controller-manager kubeconfig file found, verifying the authenticity\n"
-                KCMKUBECONFIG_SUBJECT=$(cat $KCMKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 --text | grep "Subject: CN" | tr -d " ")
-                KCMKUBECONFIG_ISSUER=$(cat $KCMKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 --text | grep "Issuer: CN" | tr -d " ")
+                KCMKUBECONFIG_SUBJECT=$(cat $KCMKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -text | grep "Subject: CN" | tr -d " ")
+                KCMKUBECONFIG_ISSUER=$(cat $KCMKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -text | grep "Issuer: CN" | tr -d " ")
                KCMKUBECONFIG_CERT_MD5=$(cat $KCMKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -noout | openssl md5 | awk '{print $2}')
                KCMKUBECONFIG_KEY_MD5=$(cat $KCMKUBECONFIG | grep "client-key-data" | awk '{print $2}' | base64 --decode | openssl rsa -noout | openssl md5 | awk '{print $2}')
                KCMKUBECONFIG_SERVER=$(cat $KCMKUBECONFIG | grep "server:"| awk '{print $2}')
@ -365,8 +365,8 @@ check_cert_kskubeconfig()
        elif [ -f $KSKUBECONFIG ]
            then
                printf "${NC}kube-scheduler kubeconfig file found, verifying the authenticity\n"
-                KSKUBECONFIG_SUBJECT=$(cat $KSKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 --text | grep "Subject: CN" | tr -d " ")
-                KSKUBECONFIG_ISSUER=$(cat $KSKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 --text | grep "Issuer: CN" | tr -d " ")
+                KSKUBECONFIG_SUBJECT=$(cat $KSKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -text | grep "Subject: CN" | tr -d " ")
+                KSKUBECONFIG_ISSUER=$(cat $KSKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -text | grep "Issuer: CN" | tr -d " ")
                KSKUBECONFIG_CERT_MD5=$(cat $KSKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -noout | openssl md5 | awk '{print $2}')
                KSKUBECONFIG_KEY_MD5=$(cat $KSKUBECONFIG | grep "client-key-data" | awk '{print $2}' | base64 --decode | openssl rsa -noout | openssl md5 | awk '{print $2}')
                KSKUBECONFIG_SERVER=$(cat $KSKUBECONFIG | grep "server:"| awk '{print $2}')
@ -392,8 +392,8 @@ check_cert_adminkubeconfig()
        elif [ -f $ADMINKUBECONFIG ]
            then
                printf "${NC}admin kubeconfig file found, verifying the authenticity\n"
-                ADMINKUBECONFIG_SUBJECT=$(cat $ADMINKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 --text | grep "Subject: CN" | tr -d " ")
-                ADMINKUBECONFIG_ISSUER=$(cat $ADMINKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 --text | grep "Issuer: CN" | tr -d " ")
+                ADMINKUBECONFIG_SUBJECT=$(cat $ADMINKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -text | grep "Subject: CN" | tr -d " ")
+                ADMINKUBECONFIG_ISSUER=$(cat $ADMINKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -text | grep "Issuer: CN" | tr -d " ")
                ADMINKUBECONFIG_CERT_MD5=$(cat $ADMINKUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -noout | openssl md5 | awk '{print $2}')
                ADMINKUBECONFIG_KEY_MD5=$(cat $ADMINKUBECONFIG | grep "client-key-data" | awk '{print $2}' | base64 --decode | openssl rsa -noout | openssl md5 | awk '{print $2}')
                ADMINKUBECONFIG_SERVER=$(cat $ADMINKUBECONFIG | grep "server:"| awk '{print $2}')
@ -611,8 +611,8 @@ check_cert_worker_1_kubeconfig()
        elif [ -f $WORKER_1_KUBECONFIG ]
            then
                printf "${NC}worker-1 kubeconfig file found, verifying the authenticity\n"
-                WORKER_1_KUBECONFIG_SUBJECT=$(cat $WORKER_1_KUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 --text | grep "Subject: CN" | tr -d " ")
-                WORKER_1_KUBECONFIG_ISSUER=$(cat $WORKER_1_KUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 --text | grep "Issuer: CN" | tr -d " ")
+                WORKER_1_KUBECONFIG_SUBJECT=$(cat $WORKER_1_KUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -text | grep "Subject: CN" | tr -d " ")
+                WORKER_1_KUBECONFIG_ISSUER=$(cat $WORKER_1_KUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -text | grep "Issuer: CN" | tr -d " ")
                WORKER_1_KUBECONFIG_CERT_MD5=$(cat $WORKER_1_KUBECONFIG | grep "client-certificate-data:" | awk '{print $2}' | base64 --decode | openssl x509 -noout | openssl md5 | awk '{print $2}')
                WORKER_1_KUBECONFIG_KEY_MD5=$(cat $WORKER_1_KUBECONFIG | grep "client-key-data" | awk '{print $2}' | base64 --decode | openssl rsa -noout | openssl md5 | awk '{print $2}')
                WORKER_1_KUBECONFIG_SERVER=$(cat $WORKER_1_KUBECONFIG | grep "server:"| awk '{print $2}')