8 files changed, 44 insertions, 0 deletions

diff --git a/util/__pycache__/exceptions.cpython-310.pyc b/util/__pycache__/exceptions.cpython-310.pyc
new file mode 100644
index 0000000..f00abf6
--- /dev/null
+++ b/util/__pycache__/exceptions.cpython-310.pyc
diff --git a/util/__pycache__/exceptions.cpython-39.pyc b/util/__pycache__/exceptions.cpython-39.pyc
new file mode 100644
index 0000000..3e6ee44
--- /dev/null
+++ b/util/__pycache__/exceptions.cpython-39.pyc
diff --git a/util/__pycache__/helpers.cpython-39.pyc b/util/__pycache__/helpers.cpython-39.pyc
new file mode 100644
index 0000000..2522a13
--- /dev/null
+++ b/util/__pycache__/helpers.cpython-39.pyc
diff --git a/util/__pycache__/runners.cpython-310.pyc b/util/__pycache__/runners.cpython-310.pyc
new file mode 100644
index 0000000..81b112d
--- /dev/null
+++ b/util/__pycache__/runners.cpython-310.pyc
diff --git a/util/__pycache__/runners.cpython-39.pyc b/util/__pycache__/runners.cpython-39.pyc
new file mode 100644
index 0000000..6e66aae
--- /dev/null
+++ b/util/__pycache__/runners.cpython-39.pyc
diff --git a/util/exceptions.py b/util/exceptions.py
new file mode 100644
index 0000000..b14896d
--- /dev/null
+++ b/util/exceptions.py
@@ -0,0 +1,2 @@
+class StepFailedError(Exception):
+    pass
diff --git a/util/helpers.py b/util/helpers.py
new file mode 100644
index 0000000..5f970df
--- /dev/null
+++ b/util/helpers.py
@@ -0,0 +1,13 @@
+import os
+
+OS_TYPE = os.getenv("OS_TYPE")
+
+
+# Returns True if all preconditions pass
+def check_preconditions(obj):
+    if "preconditions" in obj:
+        if ("os" in obj["preconditions"]
+                and obj["preconditions"]["os"] != OS_TYPE):
+            return False
+
+    return True
diff --git a/util/runners.py b/util/runners.py
new file mode 100644
index 0000000..9252d86
--- /dev/null
+++ b/util/runners.py
@@ -0,0 +1,29 @@
+import os
+import re
+from util.exceptions import StepFailedError
+
+HOME = os.getenv("HOME")
+
+
+def run_step(step):
+    step_type = step["=="]
+
+    if step_type == "run":
+        do_run(step["command"])
+    elif step_type == "link":
+        do_link(step["from"], step["to"])
+
+
+def do_run(command):
+    print(f"! {command}")
+    if not os.system(command) == 0:
+        raise StepFailedError("Non-zero return code")
+
+
+def do_link(source, destination):
+    destination = re.sub(r"^~/", HOME + "/", destination)
+    print(f"Linking {source} -> {destination}")
+    try:
+        os.link(source, destination)
+    except Exception as e:
+        raise StepFailedError("Link raised exeption: " + str(e)) from e