build_docs: shared nvm dir

Author: sdarwin

build_docs/linuxdocs.sh

@@ -199,21 +199,29 @@ if [ "$skippackagesoption" != "yes" ]; then
 
     if [ "$typeoption" = "antora" ] || [ "$install_antora_deps" = "yes" ]; then
 
-        mkdir -p ~/".nvm_${REPONAME}_antora"
+        # A shared nvm installation potentially exists in /opt/nvm
+        # and it saves disk space and downloads.
+
+        if [ -d "/opt/nvm" ]; then
+            export NVM_DIR=/opt/nvm
+            echo "Use shared nvm installation"
+        else
+            export NVM_DIR=$HOME/.nvm_${REPONAME}_antora
+            echo "Use home dir nvm installation"
+        fi
+        mkdir -p "$NVM_DIR"
         export NODE_VERSION=18.18.1
         # The container has a pre-installed nodejs. Overwrite those again.
-        export NVM_BIN="$HOME/.nvm_${REPONAME}_antora/versions/node/v${NODE_VERSION}/bin"
-        export NVM_DIR=$HOME/.nvm_${REPONAME}_antora
-        export NVM_INC=$HOME/.nvm_${REPONAME}_antora/versions/node/v${NODE_VERSION}/include/node
+        export NVM_BIN="$NVM_DIR/versions/node/v${NODE_VERSION}/bin"
+        export NVM_INC=$NVM_DIR/versions/node/v${NODE_VERSION}/include/node
         curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.5/install.sh | bash
-        export NVM_DIR=$HOME/.nvm_${REPONAME}_antora
         # shellcheck source=/dev/null
         . "$NVM_DIR/nvm.sh" && nvm install ${NODE_VERSION}
         # shellcheck source=/dev/null
         . "$NVM_DIR/nvm.sh" && nvm use v${NODE_VERSION}
         # shellcheck source=/dev/null
         . "$NVM_DIR/nvm.sh" && nvm alias default v${NODE_VERSION}
-        export PATH="$HOME/.nvm_${REPONAME}_antora/versions/node/v${NODE_VERSION}/bin/:${PATH}"
+        export PATH="$NVM_DIR/versions/node/v${NODE_VERSION}/bin/:${PATH}"
         node --version
         npm --version
         npm install gulp-cli@2.3.0
@@ -301,15 +309,21 @@ if [ -f "${pythonvirtenvpath}/bin/activate" ]; then
 fi
 
 # In the above 'packages' section npm was installed. Activate it, if that has not been done already.
-if [ -d "$HOME/.nvm_${REPONAME}_antora" ]; then
+if [ -d "/opt/nvm" ]; then
+    export NVM_DIR=/opt/nvm
+    echo "Use shared nvm installation"
+else
+    export NVM_DIR=$HOME/.nvm_${REPONAME}_antora
+    echo "Use home dir nvm installation"
+fi
+if [ -d "$NVM_DIR" ]; then
         export NODE_VERSION=18.18.1
         # The container has a pre-installed nodejs. Overwrite those again.
-        export NVM_BIN="$HOME/.nvm_${REPONAME}_antora/versions/node/v${NODE_VERSION}/bin"
-        export NVM_DIR=$HOME/.nvm_${REPONAME}_antora
-        export NVM_INC=$HOME/.nvm_${REPONAME}_antora/versions/node/v${NODE_VERSION}/include/node
+        export NVM_BIN="$NVM_DIR/versions/node/v${NODE_VERSION}/bin"
+        export NVM_INC=$NVM_DIR/versions/node/v${NODE_VERSION}/include/node
         # shellcheck source=/dev/null
         . "$NVM_DIR/nvm.sh" && nvm use "v${NODE_VERSION}"
-        export PATH="$HOME/.nvm_${REPONAME}_antora/versions/node/v${NODE_VERSION}/bin/:${PATH}"
+        export PATH="$NVM_DIR/versions/node/v${NODE_VERSION}/bin/:${PATH}"
         node --version
         npm --version
 fi