Score Higher on Verified XK0-006 | CompTIA Linux+ V8 Exam Questions with Answers

This issue is directly related to SELinux enforcement, which is a key topic in the Security domain of CompTIA Linux+ V8. The logs clearly indicate that SSH key-based authentication is failing due to an SELinux access control violation rather than a traditional file permission or SSH configuration problem.

The most important clue is the AVC denial message, which shows that the sshd process is being denied read access to the authorized_keys file. The security context of the file is listed as unconfined_u:object_r:home_root_t:s0. Under a targeted SELinux policy, SSH is only permitted to read authorized_keys files that are labeled with the correct SELinux type, typically ssh_home_t.

Because SELinux is running in enforcing mode, it actively blocks access that violates policy rules, even if standard UNIX permissions are correct. Although the file permissions (600) are acceptable for an authorized_keys file, SELinux does not rely solely on traditional permissions. The mismatch between the expected SELinux context and the actual context prevents sshd from accessing the file, causing SSH to fall back to password authentication.

Option D correctly identifies the root cause: the authorized_keys file does not have the correct SELinux security context. This is a well-documented Linux+ V8 troubleshooting scenario, commonly resolved by restoring the correct context using commands such as restorecon or by ensuring the file resides in a properly labeled home directory.

The other options are incorrect. Restarting sshd does not fix SELinux labeling issues. The policy itself is functioning as intended, and file ownership alone does not override SELinux access controls.

Linux+ V8 documentation emphasizes that SELinux denials must be addressed by correcting file contexts rather than weakening security controls. Therefore, the correct answer is D.

Version control is a core DevOps practice, and CompTIA Linux+ V8 includes Git fundamentals as part of automation and orchestration objectives. To create a new local Git repository, the correct command is git init.

The git init command initializes a new Git repository in the current directory by creating a hidden .git directory. This directory contains all the metadata required for version control, including commit history, branches, configuration settings, and object storage. After running git init, the directory becomes a fully functional local repository ready to track files and commits.

The other options do not create a new repository. git clone is used to copy an existing remote repository to a local system, not to create a new one. git config is used to set Git configuration values such as username, email, or default editor. git add stages files for commit but only works after a repository has already been initialized.

Linux+ V8 documentation highlights git init as the foundational command for starting version control in new projects. This command is frequently used in DevOps workflows when creating infrastructure-as-code repositories, automation scripts, or application source trees from scratch.

By initializing a local repository, engineers can begin tracking changes, collaborating with others, and integrating Git into CI/CD pipelines. Therefore, the correct answer is A. git init.

Environment variables in Linux can exist either locally within a shell or be exported to child processes. CompTIA Linux+ V8 emphasizes the distinction between shell variables and environment variables, as this affects how applications inherit configuration values.

Option D, export ENABLE_AUTH=1, is the correct choice because it both assigns the variable and marks it for export to the environment. Once exported, the variable becomes available to all subsequently executed commands and child processes spawned from the current shell. This behavior is required when applications or scripts rely on environment variables for configuration.

Option B, ENABLE_AUTH=1, only sets a shell-local variable. While it is accessible within the current shell session, it is not inherited by child processes unless explicitly exported. Option A, let ENABLE_AUTH=1, performs arithmetic evaluation and does not export the variable. Option C incorrectly assigns the output of a command substitution and does not set the desired value.

Linux+ V8 documentation highlights export as the correct mechanism for making variables available system-wide within a user session. Therefore, the correct answer is D.