Generic

Tunnel internal networks via SSH with sshuttle

$ sshuttle -r dragon@172.17.10.10 10.50.0.0/16 10.49.0.0/16

Does a system support IPMI

IPMI support available:

$ sudo dmidecode --type 38
# dmidecode 3.0
Getting SMBIOS data from sysfs.
SMBIOS 3.0 present.

Invalid entry length (16). Fixed up to 11.
Handle 0x0058, DMI type 38, 18 bytes
IPMI Device Information
    Interface Type: KCS (Keyboard Control Style)
    Specification Version: 2.0
    I2C Slave Address: 0x10
    NV Storage Device: Not Present
    Base Address: 0x0000000000000CA2 (I/O)
    Register Spacing: Successive Byte Boundaries

IPMI support not available:

$ sudo dmidecode --type 38
# dmidecode 3.0
Scanning /dev/mem for entry point.
# No SMBIOS nor DMI entry point found, sorry.

Spectre & Meltdown

Note

Inspect the script. You never blindly run scripts you downloaded from the Internet, do you?

Note

Run the current kernel and install amd-microcode or intel-microcode package.

$ curl -L https://meltdown.ovh -o spectre-meltdown-checker.sh
$ chmod +x spectre-meltdown-checker.sh
$ sudo ./spectre-meltdown-checker.sh
Spectre and Meltdown mitigation detection tool v0.37+

Checking for vulnerabilities on current system
Kernel is Linux 4.4.0-127-generic #153-Ubuntu SMP Sat May 19 10:58:46 UTC 2018 x86_64
CPU is AMD EPYC 7251 8-Core Processor
[...]

Deleting all partitions

$ sudo dd if=/dev/zero of=/dev/sdc bs=512 count=1 conv=notrunc

ssh: Too many authentication failures

Description

$ ssh -i id_rsa.operator dragon@10.11.12.13
   Received disconnect from 10.11.12.13 port 22:2: Too many authentication failures
   Authentication failed.

Solution

Sometimes this is caused by too many files in ~/.ssh/. You can use the IdentitiesOnly option as a workaround.

$ ssh -o IdentitiesOnly=yes -i id_rsa.operator dragon@10.11.12.13

docker-compose: error getting credentials

error getting credentials - err: exit status 1, out: Cannot autolaunch D-Bus without X11 $DISPLAY

The problem may occur when using the Docker Compose CLI plugin on older Ubuntu version (before Focal). It can be fixed by reinstalling the package pass.