Root Pixel2 with Magisk

Root steps

1. head to Google's firmware download page for Pixel devices and select your model from the menu on the right.
2. Unzip the file, original rom
3. Looking for "image-walleye" or "image-taimen"
4. Looking for "boot.img"
5. Put "boot.img" to phone
6. Install Magisk Manager app. Tap "Install" then "Patch boot image File"\
7. Magisk Manager app should generate file "patched_boot.img". Copy file to computer
8. Restart device to boot loader mode "adb reboot bootloader"
9. Refresh boot img by command "fastboot flash boot "PATH_TO_PATCHED_BOOT.IMG"
10. Relaunch device "Fastboot reboot" and magick manager. Should see Magisk SU

Put back factory boot.img for receive system OTA

1. Restart device to boot loader mode
2. Refresh boot img by command "fastboot flash boot "PATH_TO_FACTORY_BOOT.IMG"
3. Relaunch device with "Fastboot reboot"