Add utility Taskfile for checksumming, text replacement, and Python venv creation.

taskfiles/utils.yml

@@ -0,0 +1,91 @@
+version: "3"
+
+tasks:
+  # ===
+  # CHECKSUM UTILS
+  # ===
+  compute-checksum:
+    desc: "Tries to compute a checksum for the given directory and output it to a file."
+    internal: true
+    silent: true
+    requires:
+      vars: ["DATA_DIR", "OUTPUT_FILE"]
+    cmds:
+      - >-
+        tar cf -
+        --directory "{{.DATA_DIR}}"
+        --group 0
+        --mtime "UTC 1970-01-01"
+        --numeric-owner
+        --owner 0
+        --sort name
+        . 2> /dev/null
+        | md5sum > {{.OUTPUT_FILE}}
+    # Ignore errors so that dependent tasks don't fail
+    ignore_error: true
+
+  validate-checksum:
+    desc: "Validates the checksum of the given directory matches the checksum in the given file, or
+    deletes the checksum file otherwise."
+    internal: true
+    silent: true
+    vars:
+      TMP_CHECKSUM_FILE: "{{.CHECKSUM_FILE}}.tmp"
+    requires:
+      vars: ["CHECKSUM_FILE", "DATA_DIR"]
+    cmds:
+      - task: "compute-checksum"
+        vars:
+          DATA_DIR: "{{.DATA_DIR}}"
+          OUTPUT_FILE: "{{.TMP_CHECKSUM_FILE}}"
+      - defer: "rm -f '{{.TMP_CHECKSUM_FILE}}'"
+      # Check that the directory exists and the checksum matches; otherwise delete the checksum file
+      - >-
+        (
+        test -d "{{.DATA_DIR}}"
+        && diff -q '{{.TMP_CHECKSUM_FILE}}' '{{.CHECKSUM_FILE}}' 2> /dev/null
+        ) || rm -f '{{.CHECKSUM_FILE}}'
+
+  # ===
+  # STRING UTILS
+  # ===
+  replace-text:
+    desc: "Replaces some text in a file using sed."
+    internal: true
+    requires:
+      vars: ["FILE_PATH", "SED_EXP"]
+    cmds:
+      - |-
+        # NOTE:
+        # 1. We can't use `sed -i` since `-i` has different syntax on Linux and macOS
+        # 2. We can't use `--regexp` instead of `-E` since `--regexp` is not supported on macOS
+        src="{{.FILE_PATH}}"
+        dst="{{.FILE_PATH}}.tmp"
+        sed -E '{{.SED_EXP}}' "${src}" > "${dst}"
+        mv "${dst}" "${src}"
+
+  # ===
+  # VENV UTILS
+  # ===
+  create-venv:
+    desc: "Creates a Python venv using the given requirements file."
+    internal: true
+    label: "create-venv-{{.LABEL}}"
+    requires:
+      vars: ["LABEL", "OUTPUT_DIR", "REQUIREMENTS_FILE"]
+    cmds:
+      - "rm -rf '{{.OUTPUT_DIR}}'"
+      - "python3 -m venv '{{.OUTPUT_DIR}}'"
+      # Remove calls to `hash` from the venv activation script since Task uses `gosh` rather than
+      # `bash`.
+      # NOTE: Older versions of Python's venv would only call `hash` if they detected the running
+      # shell was one that had the command, but that's not the case in newer versions.
+      - task: "replace-text"
+        vars:
+          FILE_PATH: "{{.OUTPUT_DIR}}/bin/activate"
+          SED_EXP: >-
+            s/^([[:space:]]*)hash[[:space:]]+.*/\1true/g
+      - |-
+        . "{{.OUTPUT_DIR}}/bin/activate"
+        pip3 install --upgrade pip
+        pip3 install --upgrade -r "{{.REQUIREMENTS_FILE}}"