install: Add --karg-delete

This adds `--karg-delete` to install.

In some relatively rare use cases, one might want to remove a kernel argument shipped in the container image.

Fixes: #1229
Signed-off-by: Terence Lee <hone02@gmail.com>

Author: hone

crates/lib/src/install.rs

@@ -345,6 +345,12 @@ pub(crate) struct InstallConfigOpts {
     #[clap(long)]
     pub(crate) karg: Option<Vec<CmdlineOwned>>,
 
+    /// Remove a kernel argument.  This option can be provided multiple times.
+    ///
+    /// Example: --karg-delete=nosmt --karg=console=ttyS0,115200n8
+    #[clap(long)]
+    pub(crate) karg_delete: Option<Vec<String>>,
+
     /// The path to an `authorized_keys` that will be injected into the `root` account.
     ///
     /// The implementation of this uses systemd `tmpfiles.d`, writing to a file named
@@ -1124,13 +1130,18 @@ async fn install_container(
 
     // Keep this in sync with install/completion.rs for the Anaconda fixups
     let install_config_kargs = state.install_config.as_ref().and_then(|c| c.kargs.as_ref());
+    let install_config_karg_deletes = state
+        .install_config
+        .as_ref()
+        .and_then(|c| c.karg_deletes.as_ref());
 
     // Final kargs, in order:
     // - root filesystem kargs
     // - install config kargs
     // - kargs.d from container image
     // - args specified on the CLI
     let mut kargs = Cmdline::new();
+    let mut karg_deletes = Vec::<&str>::new();
 
     kargs.extend(&root_setup.kargs);
 
@@ -1142,6 +1153,19 @@ async fn install_container(
 
     kargs.extend(&kargsd);
 
+    // delete kargs before processing cli kargs, so cli kargs can override all other configs
+    if let Some(install_config_karg_deletes) = install_config_karg_deletes {
+        for karg_delete in install_config_karg_deletes {
+            karg_deletes.push(karg_delete);
+        }
+    }
+    if let Some(deletes) = state.config_opts.karg_delete.as_ref() {
+        for karg_delete in deletes {
+            karg_deletes.push(karg_delete);
+        }
+    }
+    delete_kargs(&mut kargs, &karg_deletes);
+
     if let Some(cli_kargs) = state.config_opts.karg.as_ref() {
         for karg in cli_kargs {
             kargs.extend(karg);
@@ -1224,6 +1248,18 @@ async fn install_container(
     Ok((deployment, aleph))
 }
 
+pub(crate) fn delete_kargs(existing: &mut Cmdline, deletes: &Vec<&str>) {
+    for delete in deletes {
+        if let Some(param) = utf8::Parameter::parse(&delete) {
+            if param.value().is_some() {
+                existing.remove_exact(&param);
+            } else {
+                existing.remove(&param.key());
+            }
+        }
+    }
+}
+
 /// Run a command in the host mount namespace
 pub(crate) fn run_in_host_mountns(cmd: &str) -> Result<Command> {
     let mut c = Command::new(bootc_utils::reexec::executable_path()?);
@@ -3085,4 +3121,21 @@ UUID=boot-uuid /boot ext4 defaults 0 0
 
         Ok(())
     }
+
+    #[test]
+    fn test_delete_kargs() -> Result<()> {
+        let mut cmdline = Cmdline::from("console=tty0 quiet debug nosmt foo=bar foo=baz bar=baz");
+
+        let deletions = vec!["foo=bar", "bar", "debug"];
+
+        delete_kargs(&mut cmdline, &deletions);
+
+        let result = cmdline.to_string();
+        assert!(!result.contains("foo=bar"));
+        assert!(!result.contains("bar"));
+        assert!(!result.contains("debug"));
+        assert!(result.contains("foo=baz"));
+
+        Ok(())
+    }
 }

crates/lib/src/install/config.rs

@@ -104,6 +104,9 @@ pub(crate) struct InstallConfiguration {
     /// Kernel arguments, applied at installation time
     #[serde(skip_serializing_if = "Option::is_none")]
     pub(crate) kargs: Option<Vec<String>>,
+    /// Deleting Kernel arguments, applied at installation time
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(crate) karg_deletes: Option<Vec<String>>,
     /// Supported architectures for this configuration
     pub(crate) match_architectures: Option<Vec<String>>,
     /// Ostree repository configuration
@@ -208,6 +211,11 @@ impl Mergeable for InstallConfiguration {
                     .get_or_insert_with(Default::default)
                     .extend(other_kargs)
             }
+            if let Some(other_karg_deletes) = other.karg_deletes {
+                self.karg_deletes
+                    .get_or_insert_with(Default::default)
+                    .extend(other_karg_deletes)
+            }
         }
     }
 }
@@ -242,6 +250,7 @@ impl InstallConfiguration {
     // Remove all configuration which is handled by `install to-filesystem`.
     pub(crate) fn filter_to_external(&mut self) {
         self.kargs.take();
+        self.karg_deletes.take();
     }
 
     #[cfg(feature = "install-to-disk")]
@@ -346,6 +355,7 @@ root-fs-type = "xfs"
             r##"[install]
 root-fs-type = "ext4"
 kargs = ["console=ttyS0", "foo=bar"]
+karg-deletes = ["debug", "bar=baz"]
 "##,
         )
         .unwrap();
@@ -359,6 +369,12 @@ kargs = ["console=ttyS0", "foo=bar"]
                         .map(ToOwned::to_owned)
                         .collect(),
                 ),
+                karg_deletes: Some(
+                    ["baz", "bar=baz"]
+                        .into_iter()
+                        .map(ToOwned::to_owned)
+                        .collect(),
+                ),
                 ..Default::default()
             }),
         };
@@ -372,7 +388,16 @@ kargs = ["console=ttyS0", "foo=bar"]
                     .map(ToOwned::to_owned)
                     .collect()
             )
-        )
+        );
+        assert_eq!(
+            install.karg_deletes,
+            Some(
+                ["debug", "bar=baz", "baz", "bar=baz"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect()
+            )
+        );
     }
 
     #[test]

crates/tests-integration/src/install.rs

@@ -169,6 +169,26 @@ pub(crate) fn run_alongside(image: &str, mut testargs: libtest_mimic::Arguments)
             generic_post_install_verification()?;
             Ok(())
         }),
+        Trial::test("install with --karg-delete", move || {
+            let sh = &xshell::Shell::new()?;
+            reset_root(sh, image)?;
+            cmd!(sh, "sudo {BASE_ARGS...} {target_args...} {image} bootc install to-filesystem --acknowledge-destructive --karg-delete=localtestkarg --replace=alongside /target").run()?;
+            cmd!(
+                sh,
+                "sudo {BASE_ARGS...} {target_args...} {image} bootc install finalize /target"
+            )
+            .run()?;
+            let entries = cmd!(
+                sh,
+                "sudo /bin/sh -c 'grep localtestkarg /boot/loader/entries/*.conf'"
+            )
+            .ignore_status()
+            .read()?;
+
+            assert!(entries.is_empty());
+
+            Ok(())
+        }),
     ];
 
     libtest_mimic::run(&testargs, tests.into()).exit()

tmt/plans/integration.fmf

@@ -230,4 +230,11 @@ execute:
     how: fmf
     test:
       - /tmt/tests/tests/test-38-install-bootloader-none
+
+/plan-39-install-karg-delete:
+  summary: Test bootc install --karg-delete
+  discover:
+    how: fmf
+    test:
+      - /tmt/tests/tests/test-39-install-karg-delete
 # END GENERATED PLANS

tmt/tests/booted/test-install-karg-delete.nu

@@ -0,0 +1,53 @@
+# number: 39
+# tmt:
+#   summary: Test bootc install --karg-delete
+#   duration: 30m
+#
+use std assert
+use tap.nu
+#
+# Use an OS-matched target image to avoid version mismatches
+let target_image = (tap get_target_image)
+
+# setup filesystem
+mkdir /var/mnt
+truncate -s 10G disk.img
+mkfs.ext4 disk.img
+mount -o loop disk.img /var/mnt
+
+# Mask off the bootupd state to reproduce https://github.com/bootc-dev/bootc/issues/1778
+# Also it turns out that installation outside of containers dies due to `error: Multiple commit objects found`
+# so we mask off /sysroot/ostree
+# And using systemd-run here breaks our install_t so we disable SELinux enforcement
+setenforce 0
+
+mkdir /etc/bootc/install
+{ install: { kargs: ["foo=bar"] } } | to toml | save /etc/bootc/install/99-test.toml
+
+let base_args = $"bootc install to-filesystem --disable-selinux --source-imgref ($target_image) --karg-delete localtestkarg --karg-delete foo"
+let install_cmd = if (tap is_composefs) {
+    let st = bootc status --json | from json
+    let bootloader = ($st.status.booted.composefs.bootloader | str downcase)
+    $"($base_args) --composefs-backend --bootloader=($bootloader) /var/mnt"
+} else {
+    $"($base_args) --bootloader none /var/mnt"
+}
+
+tap run_install $install_cmd
+
+# Verify the karg is gone from the bootloader entries
+let entries = (glob /var/mnt/boot/loader/entries/*.conf
+    | each { open $in | lines }
+    | flatten)
+
+let localtestkarg_found = ($entries | find "localtestkarg" | is-empty)
+assert $localtestkarg_found "Found localtestkarg in bootloader entries, but it should have been deleted"
+
+let foo_found = ($entries | find "foo" | is-empty)
+assert $foo_found "Found foo in bootloader entries, but it should have been deleted"
+
+# Clean up
+umount /var/mnt
+rm -rf disk.img
+
+tap ok

tmt/tests/tests.fmf

@@ -131,3 +131,8 @@
   summary: Test bootc install with --bootloader=none
   duration: 30m
   test: nu booted/test-install-bootloader-none.nu
+
+/test-39-install-karg-delete:
+  summary: Test bootc install --karg-delete
+  duration: 30m
+  test: nu booted/test-install-karg-delete.nu