Before we see how the behind-the-scenes thing works, let's look at how to SSH into the minikube VM. You can do it like this -
First, start the minikube VM with hyperkit driver
# Run the minikube VM like this
mk start --driver hyperkit
If you don't have hyperkit, then install it using brew (Homebrew)
brew install hyperkit
Next, let's SSH into the minikube VM
minikube ssh
And the output would look like this -
$ minikube ssh
_ _
_ _ ( ) ( )
___ ___ (_) ___ (_)| |/') _ _ | |_ __
/' _ ` _ `\| |/' _ `\| || , < ( ) ( )| '_`\ /'__`\
| ( ) ( ) || || ( ) || || |\`\ | (_) || |_) )( ___/
(_) (_) (_)(_)(_) (_)(_)(_) (_)`\___/'(_,__/'`\____)
$
Now let's look at how this thing works behind the scenes :)
Now, let's think about this - what information does one require to SSH into a machine? Remote or local, regardless
One would need to know the IP address of the server running in the machine (at which it's listening at); one would need to know the port at which the SSH server is running; we also need to know the SSH credentials - for example SSH username and password, or something like SSH username and SSH private key, if the credential is a key. By the way, this is all assuming that one can SSH into the machine - that is, there's an SSH server running at a given port and the port is accessible from the machine we have, with no firewall issues etc
Let's try to get all of this information now
Let's look at what minikube profile we are using first
minikube profile list
You can see output like this -
$ mk profile list
|----------|-----------|---------|--------------|------|---------|---------|-------|--------|
| Profile | VM Driver | Runtime | IP | Port | Version | Status | Nodes | Active |
|----------|-----------|---------|--------------|------|---------|---------|-------|--------|
| minikube | hyperkit | docker | 192.168.65.2 | 8443 | v1.27.4 | Running | 1 | * |
|----------|-----------|---------|--------------|------|---------|---------|-------|--------|
We have a profile named minikube profile in my case. It's a default profile name I think, when no name is used during minikube start command
Look for the profile's machine details under ~/.minikube/machines/<profile-name>/config.json . For example, for minikube profile, in my case, it looks like this - ~/.minikube/machines/minikube/config.json -
{
"ConfigVersion": 3,
"Driver": {
"IPAddress": "192.168.65.2",
"MachineName": "minikube",
"SSHUser": "docker",
"SSHPort": 22,
"SSHKeyPath": "/Users/karuppiah/.minikube/machines/minikube/id_rsa",
"StorePath": "/Users/karuppiah/.minikube",
"SwarmMaster": false,
"SwarmHost": "",
"SwarmDiscovery": "",
"Boot2DockerURL": "file:///Users/karuppiah/.minikube/cache/iso/amd64/minikube-v1.31.0-amd64.iso",
"DiskSize": 20000,
"CPU": 2,
"Memory": 4000,
"Cmdline": "loglevel=3 console=ttyS0 console=tty0 noembed nomodeset norestore waitusb=10 systemd.legacy_systemd_cgroup_controller=yes random.trust_cpu=on hw_rng_model=virtio base host=minikube",
"NFSShares": [],
"NFSSharesRoot": "/nfsshares",
"UUID": "7aa1c19a-6834-11ee-a8ca-acde48001122",
"VpnKitSock": "",
"VSockPorts": [],
"ExtraDisks": 0
},
"DriverName": "hyperkit",
"HostOptions": {
"Driver": "",
"Memory": 0,
"Disk": 0,
"EngineOptions": {
"ArbitraryFlags": null,
"Dns": null,
"GraphDir": "",
"Env": null,
"Ipv6": false,
"InsecureRegistry": [
"10.96.0.0/12"
],
"Labels": null,
"LogLevel": "",
"StorageDriver": "",
"SelinuxEnabled": false,
"TlsVerify": false,
"RegistryMirror": [],
"InstallURL": "https://get.docker.com"
},
"SwarmOptions": {
"IsSwarm": false,
"Address": "",
"Discovery": "",
"Agent": false,
"Master": false,
"Host": "tcp://0.0.0.0:3376",
"Image": "swarm:latest",
"Strategy": "spread",
"Heartbeat": 0,
"Overcommit": 0,
"ArbitraryFlags": null,
"ArbitraryJoinFlags": null,
"Env": null,
"IsExperimental": false
},
"AuthOptions": {
"CertDir": "/Users/karuppiah/.minikube",
"CaCertPath": "/Users/karuppiah/.minikube/certs/ca.pem",
"CaPrivateKeyPath": "/Users/karuppiah/.minikube/certs/ca-key.pem",
"CaCertRemotePath": "",
"ServerCertPath": "/Users/karuppiah/.minikube/machines/server.pem",
"ServerKeyPath": "/Users/karuppiah/.minikube/machines/server-key.pem",
"ClientKeyPath": "/Users/karuppiah/.minikube/certs/key.pem",
"ServerCertRemotePath": "",
"ServerKeyRemotePath": "",
"ClientCertPath": "/Users/karuppiah/.minikube/certs/cert.pem",
"ServerCertSANs": null,
"StorePath": "/Users/karuppiah/.minikube"
}
},
"Name": "minikube"
}
It contains all the details, like SSH key path, SSH server port, SSH username, SSH server IP address
...
"Driver": {
"IPAddress": "192.168.65.2",
"MachineName": "minikube",
"SSHUser": "docker",
"SSHPort": 22,
"SSHKeyPath": "/Users/karuppiah/.minikube/machines/minikube/id_rsa",
...
I found the SSH key just by experimenting and looking for folders and files named ssh and similar in my machine. I found the private key credential for SSHing into the machine at ~/.minikube/machines/minikube/id_rsa , which is mentioned in the profile config JSON
I found the username by using whoami after getting into the machine with minikube ssh and it's the same one mentioned in the profile config JSON. I checked IP using minikube profile list table. You can also find the IP using ifconfig after getting into the machine with minikube ssh, like this -
$ minikube ssh
_ _
_ _ ( ) ( )
___ ___ (_) ___ (_)| |/') _ _ | |_ __
/' _ ` _ `\| |/' _ `\| || , < ( ) ( )| '_`\ /'__`\
| ( ) ( ) || || ( ) || || |\`\ | (_) || |_) )( ___/
(_) (_) (_)(_)(_) (_)(_)(_) (_)`\___/'(_,__/'`\____)
$ whoami
docker
$
$ ifconfig
bridge Link encap:Ethernet HWaddr 9A:C4:47:0F:A9:8C
inet addr:10.244.0.1 Bcast:10.244.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1078 errors:0 dropped:0 overruns:0 frame:0
TX packets:1183 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:88539 (86.4 KiB) TX bytes:118699 (115.9 KiB)
docker0 Link encap:Ethernet HWaddr 02:42:DE:3F:40:E0
inet addr:172.17.0.1 Bcast:172.17.255.255 Mask:255.255.0.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
eth0 Link encap:Ethernet HWaddr 66:8F:EF:A0:31:45
inet addr:192.168.65.2 Bcast:192.168.65.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:295237 errors:0 dropped:0 overruns:0 frame:0
TX packets:15928 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:432434274 (412.4 MiB) TX bytes:1653741 (1.5 MiB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:175877 errors:0 dropped:0 overruns:0 frame:0
TX packets:175877 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:30983261 (29.5 MiB) TX bytes:30983261 (29.5 MiB)
veth1325a6d7 Link encap:Ethernet HWaddr 96:06:58:31:BD:D7
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1079 errors:0 dropped:0 overruns:0 frame:0
TX packets:1183 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:103673 (101.2 KiB) TX bytes:118687 (115.9 KiB)
$
These details are also in the profile config JSON. The SSH server port is 22, which is the default port.
So, with all that information, let's see how minikube ssh works behind the scenes. We have the private key, we have the IP address along with the port number and we have the username too. Finally, it looks like this -
ssh -i ~/.minikube/machines/minikube/id_rsa docker@192.168.65.2
$ ssh -i ~/.minikube/machines/minikube/id_rsa docker@192.168.65.2
_ _
_ _ ( ) ( )
___ ___ (_) ___ (_)| |/') _ _ | |_ __
/' _ ` _ `\| |/' _ `\| || , < ( ) ( )| '_`\ /'__`\
| ( ) ( ) || || ( ) || || |\`\ | (_) || |_) )( ___/
(_) (_) (_)(_)(_) (_)(_)(_) (_)`\___/'(_,__/'`\____)
$
So, that's how minikube ssh works in MacOS with Hyperkit VMs