feat: install and remove a package

Sponsored-by: author

3 files changed, 37 insertions, 5 deletions

diff --git a/debian.md b/debian.md
index 5f9d29e..ba35311 100644
--- a/debian.md
+++ b/debian.md
@@ -57,3 +57,26 @@ given a Debian system
 when I run, as debian, sudo apt update
 then command is successful
 ~~~
+
+## Can install and remove a package
+
+_Requirement: The system administrator can install and remove a
+package._
+
+Justification: Without this, it may be impossible to install a bug fix
+or security update.
+
+The scenario uses the `liwc` package, which is rarely used or
+installed by anyone. If your Debian system does have it, this will
+fail and you will need to edit the scenario to use a different
+package.
+
+~~~scenario
+given a Debian system
+when I try to run, as debian, dpkg -l liwc
+then command fails
+when I run, as debian, sudo apt update
+when I run, as debian, sudo apt install -y liwc
+when I run, as debian, sudo apt remove -y liwc
+then command is successful
+~~~
diff --git a/debian.py b/debian.py
index 7456d8a..ec14bd8 100644
--- a/debian.py
+++ b/debian.py
@@ -15,13 +15,17 @@ def debian_system(ctx, hostname=None):
 
 
 def run_as_on_host(ctx, username=None, argv0=None, args=None):
-    runcmd_run = globals()["runcmd_run"]
     runcmd_exit_code_is_zero = globals()["runcmd_exit_code_is_zero"]
+    try_to_run_as_on_host(ctx, username=username, argv0=argv0, args=args)
+    runcmd_exit_code_is_zero(ctx)
+
 
-    logging.debug(f"run_as_on_host: username={username!r}")
-    logging.debug(f"run_as_on_host: argv0={argv0!r}")
-    logging.debug(f"run_as_on_host: args={args!r}")
+def try_to_run_as_on_host(ctx, username=None, argv0=None, args=None):
+    runcmd_run = globals()["runcmd_run"]
+
+    logging.debug(f"try_to_run_as_on_host: username={username!r}")
+    logging.debug(f"try_to_run_as_on_host: argv0={argv0!r}")
+    logging.debug(f"try_to_run_as_on_host: args={args!r}")
     target = f"{username}@{ctx['hostname']}"
     argv = ["ssh", target, "--", shlex.quote(argv0)] + shlex.split(args)
     runcmd_run(ctx, argv)
-    runcmd_exit_code_is_zero(ctx)
diff --git a/debian.yaml b/debian.yaml
index 45497ee..c488841 100644
--- a/debian.yaml
+++ b/debian.yaml
@@ -7,3 +7,8 @@
   impl:
     python:
       function: run_as_on_host
+
+- when: I try to run, as {username}, {argv0}{args:text}
+  impl:
+    python:
+      function: try_to_run_as_on_host