add epics-containers style postCreate to devcontainer

Author: gilesknap

.devcontainer/devcontainer.json

@@ -9,6 +9,7 @@
         // Allow X11 apps to run inside the container
         "DISPLAY": "${localEnv:DISPLAY}"
     },
+    "remoteUser": "${localEnv:EC_REMOTE_USER}",
     "customizations": {
         "vscode": {
             // Set *default* container specific settings.json values on container create.
@@ -33,14 +34,16 @@
             "upgradePackages": false
         }
     },
+    // You can place any outside of the container before-launch commands here
+    "initializeCommand": "bash .devcontainer/initializeCommand ${devcontainerId}",
+    // One time global setup commands inside the container
+    "postCreateCommand": "bash .devcontainer/postCreateCommand ${devcontainerId}",
     "runArgs": [
         // Allow the container to access the host X11 display and EPICS CA
         "--net=host",
         // Make sure SELinux does not disable with access to host filesystems like tmp
         "--security-opt=label=disable"
     ],
     // Mount the parent as /workspaces so we can pip install peers as editable
-    "workspaceMount": "source=${localWorkspaceFolder}/..,target=/workspaces,type=bind",
-    // After the container is created, install the python project in editable form
-    "postCreateCommand": "pip install $([ -f dev-requirements.txt ] && echo '-c dev-requirements.txt') -e '.[dev]' && pre-commit install"
+    "workspaceMount": "source=${localWorkspaceFolder}/..,target=/workspaces,type=bind"
 }

.devcontainer/initializeCommand

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+# custom initialization goes here - runs outside of the dev container
+# just before the container is launched but after the container is created
+
+echo "devcontainerID ${1}"

.devcontainer/postCreateCommand

@@ -0,0 +1,31 @@
+#!/bin/bash
+
+# Custom initialization goes here if needed.
+# Runs inside the dev container after the container is created
+
+################################################################################
+# When using docker we will not be root inside the container
+# the following steps are then required
+################################################################################
+
+if [[ $USER != "root" ]] ; then
+    # make sure the non-root user can access the virtual environment
+    sudo chown -R ${USER}:${USER} /venv
+fi
+
+################################################################################
+# Shell customizations
+################################################################################
+
+# pick a theme that does not cause completion corruption in zsh
+sed -i $HOME/.zshrc -e 's/ZSH_THEME="devcontainers"/ZSH_THEME="lukerandall"/'
+
+# allow personalization of all devcontainers in this subdirectory
+# by placing a .devcontainer_rc file in the workspace root
+if [[ -f /workspaces/.devcontainer_rc ]] ; then
+    source /workspaces/.devcontainer_rc
+fi
+
+#After the container is created, install the python project in editable form
+pip install $([ -f dev-requirements.txt ] && echo '-c dev-requirements.txt') -e '.[dev]'
+pre-commit install