Skip to content

Commit 7a73cf8

Browse files
ShaunaDiazShaunaDiaz
authored
Merge pull request #70065 from ShaunaDiaz/OSDOCS-7308
OSDOCS-7308: run MicroShift on disconnected host
2 parents a837529 + cd132c2 commit 7a73cf8

File tree

6 files changed

+214
-0
lines changed

6 files changed

+214
-0
lines changed

‎_topic_maps/_topic_map_ms.yml

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -404,6 +404,8 @@ Topics:
404404
File: microshift-networking-settings
405405
- Name: Firewall configuration
406406
File: microshift-firewall
407+
- Name: Networking settings for fully disconnected hosts
408+
File: microshift-disconnected-network-config
407409
---
408410
Name: Storage
409411
Dir: microshift_storage

‎microshift_install/microshift-embed-in-rpm-ostree-offline-use.adoc

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -33,3 +33,4 @@ include::modules/microshift-creating-ostree-iso.adoc[leveloffset=+2]
3333

3434
* link:https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/composing_a_customized_rhel_system_image/assembly_pushing-a-container-to-a-register-and-embedding-it-into-a-image_composing-a-customized-rhel-system-image#con_the-container-registry-credentials_assembly_pushing-a-container-to-a-register-and-embedding-it-into-a-image[Pushing a container to a registry and embedding it into an image]
3535
* link:https://www.osbuild.org/guides/image-builder-on-premises/container-auth.html[Container registry credentials]
36+
* xref:../microshift_networking/microshift-disconnected-network-config.adoc#microshift-disconnected-network-config[Configuring network settings for fully disconnected hosts]

‎microshift_networking/microshift-disconnected-network-config.adoc

Lines changed: 14 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,14 @@
1+
:_mod-docs-content-type: ASSEMBLY
2+
[id="microshift-disconnected-network-config"]
3+
= Configuring network settings for fully disconnected hosts
4+
include::_attributes/attributes-microshift.adoc[]
5+
:context: microshift-networking-disconnected-hosts
6+
toc::[]
7+
8+
Learn how to apply networking customization and settings to run {microshift-short} on fully disconnected hosts. A disconnected host should be the {op-system-base-full} operating system, versions 9.0+, whether real or virtual, that runs without network connectivity.
9+
10+
include::modules/microshift-disconnected-host-con.adoc[leveloffset=+1]
11+
12+
include::modules/microshift-undo-network-config.adoc[leveloffset=+1]
13+
14+
include::modules/microshift-disconnected-host-procedure.adoc[leveloffset=+1]

‎modules/microshift-disconnected-host-con.adoc

Lines changed: 38 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,38 @@
1+
// Module included in the following assemblies:
2+
//
3+
// * microshift_networking/microshift-disconnected-network-config.adoc
4+
5+
:_mod-docs-content-type: CONCEPT
6+
[id="microshift-disconnected-host-preparation_{context}"]
7+
= Preparing networking for fully disconnected hosts
8+
9+
Use the procedure that follows to start and run {microshift-short} clusters on devices running fully disconnected operating systems. A {microshift-short} host is considered fully disconnected if it has no external network connectivity.
10+
11+
Typically this means that the device does not have an attached network interface controller (NIC) to provide a subnet. These steps can also be completed on a host with a NIC that is removed after setup. You can also automate these steps on a host that does not have a NIC by using the `%post` phase of a Kickstart file.
12+
13+
[IMPORTANT]
14+
====
15+
Configuring networking settings for disconnected environments is necessary because {microshift-short} requires a network device to support cluster communication. To meet this requirement, you must configure {microshift-short} networking settings to use the "fake" IP address you assign to the system loopback device during setup.
16+
====
17+
18+
[id="microshift-disconnected-host-procedure-summary{context}"]
19+
== Procedure summary
20+
21+
To run {microshift-short} on a disconnected host, the following steps are required:
22+
23+
Prepare the host::
24+
* Stop {microshift-short} if it is currently running and clean up changes the service has made to the network.
25+
* Set a persistent hostname.
26+
* Add a “fake” IP address on the loopback interface.
27+
* Configure DNS to use the fake IP as local name server.
28+
* Add an entry for the hostname to `/etc/hosts`.
29+
30+
Update the {microshift-short} configuration::
31+
* Define the `nodeIP` parameter as the new loopback IP address.
32+
* Set the `.node.hostnameOverride` parameter to the persistent hostname.
33+
34+
For the changes to take effect::
35+
* Disable the default NIC if attached.
36+
* Restart the host or device.
37+
38+
After starting, {microshift-short} runs using the loopback device for within-cluster communication.

‎modules/microshift-disconnected-host-procedure.adoc

Lines changed: 120 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,120 @@
1+
// Module included in the following assemblies:
2+
//
3+
// * microshift_networking/microshift-disconnected-network-config.adoc
4+
5+
:_mod-docs-content-type: PROCEDURE
6+
[id="microshift-disconnected-host-network-config_{context}"]
7+
= Configuring the networking settings for fully disconnected hosts
8+
9+
To configure the networking settings for running {microshift-short} on a fully disconnected host, you must prepare the host, update the networking configuration, then restart to apply the new settings. All commands are executed from the host CLI.
10+
11+
.Prerequisites
12+
* RHEL 9 or newer.
13+
* {microshift-short} 4.14 or newer.
14+
* Access to the host CLI.
15+
* A valid IP address chosen to avoid both internal and potential future external IP conflicts when running {microshift-short}.
16+
* {microshift-short} networking settings are set to defaults.
17+
18+
[IMPORTANT]
19+
====
20+
The following procedure is for use cases in which access to the {microshift-short} cluster is not required after devices are deployed in the field. There is no remote cluster access after the network connection is removed.
21+
====
22+
23+
.Procedure
24+
25+
. Add a fake IP address to the loopback interface by running the following command:
26+
+
27+
[source,terminal]
28+
----
29+
$ IP="10.44.0.1" <1>
30+
$ sudo nmcli con add type loopback con-name stable-microshift ifname lo ip4 ${IP}/32
31+
----
32+
<1> The fake IP address used in this example is “10.44.0.1”.
33+
+
34+
[NOTE]
35+
====
36+
Any valid IP works if it avoids both internal {microshift-short} and potential future external IP conflicts. This can be any subnet that does not collide with the {microshift-short} node subnet or is be accessed by other services on the device.
37+
====
38+
39+
. Configure the DNS interface to use the local name server by setting modifying the settings to ignore automatic DNS and reset it to the local name server:
40+
+
41+
.. Bypass the automatic DNS by running the following command:
42+
+
43+
[source,terminal]
44+
----
45+
$ sudo nmcli conn modify stable-microshift ipv4.ignore-auto-dns yes
46+
----
47+
+
48+
.. Point the DNS interface to use the local name server:
49+
+
50+
[source,terminal]
51+
----
52+
$ sudo nmcli conn modify stable-microshift ipv4.dns "10.44.1.1"
53+
----
54+
55+
. Get the hostname of the device by running the following command:
56+
+
57+
[source,terminal]
58+
----
59+
$ NAME="$(hostnamectl hostname)"
60+
----
61+
62+
. Add an entry for the hostname of the node in the `/etc/hosts` file by running the following command:
63+
+
64+
[source,terminal]
65+
----
66+
$ echo "$IP $NAME" | sudo tee -a /etc/hosts >/dev/null
67+
----
68+
69+
. Update the {microshift-short} configuration file by adding the following YAML snippet to `/etc/microshift/config.yaml`:
70+
+
71+
[source,terminal]
72+
----
73+
sudo tee /etc/microshift/config.yaml > /dev/null <<EOF
74+
node:
75+
hostnameOverride: hostnameOverride: $(echo $NAME)
76+
nodeIP: $(echo $IP)
77+
EOF
78+
----
79+
80+
. {microshift-short} is now ready to use the loopback device for cluster communications. Finish preparing the device for offline use.
81+
82+
.. If the device currently has a NIC attached, disconnect the device from the network.
83+
.. Shut down the device and disconnect the NIC.
84+
.. Restart the device for the offline configuration to take effect.
85+
86+
. Restart the {microshift-short} host to apply the configuration changes by running the following command:
87+
+
88+
[source,terminal]
89+
----
90+
$ sudo systemctl reboot <1>
91+
----
92+
<1> This step restarts the cluster. Wait for the greenboot health check to report the system healthy before implementing verification.
93+
94+
.Verification
95+
96+
At this point, network access to the {microshift-short} host has been severed. If you have access to the host terminal, you can use the host CLI to verify that the cluster has started in a stable state.
97+
98+
. Verify that the {microshift-short} cluster is running by entering the following command:
99+
+
100+
[source,terminal]
101+
----
102+
$ export KUBECONFIG=/var/lib/microshift/resources/kubeadmin/kubeconfig
103+
$ sudo -E oc get pods -A
104+
----
105+
+
106+
.Example output
107+
[source,terminal]
108+
----
109+
NAMESPACE NAME READY STATUS RESTARTS AGE
110+
kube-system csi-snapshot-controller-74d566564f-66n2f 1/1 Running 0 1m
111+
kube-system csi-snapshot-webhook-69bdff8879-xs6mb 1/1 Running 0 1m
112+
openshift-dns dns-default-dxglm 2/2 Running 0 1m
113+
openshift-dns node-resolver-dbf5v 1/1 Running 0 1m
114+
openshift-ingress router-default-8575d888d8-xmq9p 1/1 Running 0 1m
115+
openshift-ovn-kubernetes ovnkube-master-gcsx8 4/4 Running 1 1m
116+
openshift-ovn-kubernetes ovnkube-node-757mf 1/1 Running 1 1m
117+
openshift-service-ca service-ca-7d7c579f54-68jt4 1/1 Running 0 1m
118+
openshift-storage topolvm-controller-6d777f795b-bx22r 5/5 Running 0 1m
119+
openshift-storage topolvm-node-fcf8l 4/4 Running 0 1m
120+
----

‎modules/microshift-undo-network-config.adoc

Lines changed: 39 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,39 @@
1+
// Module included in the following assemblies:
2+
//
3+
// * microshift_networking/microshift-disconnected-network-config.adoc
4+
5+
:_mod-docs-content-type: PROCEDURE
6+
[id="microshift-undo-network-config_{context}"]
7+
= Restoring {microshift-short} networking settings to default
8+
9+
You can remove networking customizations and return the network to default settings by stopping {microshift-short} and running a clean-up script.
10+
11+
.Prerequisites
12+
* RHEL 9 or newer.
13+
* MicroShift 4.14 or newer.
14+
* Access to the host CLI.
15+
16+
.Procedure
17+
18+
. Stop the {microshift-short} service by running the following command:
19+
+
20+
[source,terminal]
21+
----
22+
$ sudo systemctl stop microshift
23+
----
24+
25+
. Stop the `kubepods.slice` systemd unit by running the following command:
26+
+
27+
[source,terminal]
28+
----
29+
$ sudo systemctl stop kubepods.slice
30+
----
31+
32+
. {microshift-short} installs a helper script to undo network changes made by OVN-K. Run the cleanup script by entering the following command:
33+
+
34+
[source,terminal]
35+
----
36+
$ sudo /usr/bin/microshift-cleanup-data --ovn
37+
----
38+
39+
//Q: any sample output? what should we see when we run the script?

0 commit comments

Comments
 (0)