docs: Update welcome message

Author: rsenden

linux/Dockerfile

@@ -141,7 +141,7 @@ LABEL org.opencontainers.image.source="https://github.com/fortify/fcli" \
 RUN echo "fcli:x:10001:10001:fcli:/data:/sbin/nologin" >> /etc/passwd
 COPY --from=fcli-downloader /tmp/fcli-bin/fcli /usr/bin/fcli
 COPY docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh
-COPY welcome.txt /usr/share/fcli/welcome.txt
+COPY welcome*.txt /usr/share/fcli/
 RUN chmod +x /usr/local/bin/docker-entrypoint.sh
 ADD data.tgz /
 WORKDIR /data
@@ -173,7 +173,7 @@ LABEL org.opencontainers.image.source="https://github.com/fortify/fcli" \
 RUN echo "fcli:x:10001:10001:fcli:/data:/sbin/nologin" >> /etc/passwd
 COPY --from=fcli-downloader /tmp/fcli-bin/fcli /usr/bin/fcli
 COPY docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh
-COPY welcome.txt /usr/share/fcli/welcome.txt
+COPY welcome*.txt /usr/share/fcli/
 RUN chmod +x /usr/local/bin/docker-entrypoint.sh
 ADD data.tgz /
 WORKDIR /data

linux/docker-entrypoint.sh

@@ -9,8 +9,18 @@
 if [ -t 0 ] && [ $# -eq 1 ]; then
     case "$1" in
         /bin/sh|/bin/bash|sh|bash)
-            # Display welcome message for interactive shell sessions
-            cat /usr/share/fcli/welcome.txt
+            # Display base welcome message for interactive shell sessions
+            # Build an `EXTRA_NOTES` env var and interpolate it into the
+            # `${EXTRA_NOTES}` placeholder inside `welcome.txt`.
+            EXTRA_NOTES=""
+            if [ -d /opt/fortify/sc-client ] && [ -f /usr/share/fcli/welcome-sc-note.txt ]; then
+                # Prefix a blank line so the note is separated from prior text
+                EXTRA_NOTES="$(printf '\n%s' "$(cat /usr/share/fcli/welcome-sc-note.txt)")"
+            fi
+
+            # Replace literal `${EXTRA_NOTES}` placeholder with the value of
+            # the EXTRA_NOTES variable. Using awk preserves newlines.
+            awk -v extra="$EXTRA_NOTES" '{ gsub(/\$\{EXTRA_NOTES\}/, extra); print }' /usr/share/fcli/welcome.txt
             ;;
     esac
 fi

linux/welcome-sc-note.txt

@@ -0,0 +1,4 @@
+Note: This image variant also includes ScanCentral Client, which can be
+      invoked via the `scancentral` command. See `scancentral --help` or
+      the product documentation for details. Please also see note above
+      about packaging.

linux/welcome.txt

@@ -23,4 +23,14 @@ Note: fcli stores session state and cache in /data (FCLI_USER_HOME).
       For persistent state across image invocations, mount a volume: 
         docker run -v fcli-data:/data ...
 
+Note: This image does not include any build tools, and is therefore not 
+      suitable for for packaging source code through ScanCentral Client
+      for languages that require build tool integration. If the 
+      `scancentral package` command is being run within this container
+      (for example through fcli `ci` or `package` actions or direct 
+      ScanCentral Client invocation), the `-bt none` option must be
+      passed to avoid errors due to missing build tools. Depending on
+      source code language, using `-bt none` may produce inaccurate
+      scan results.
+${EXTRA_NOTES}
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