Move ssh configuration into base image.

And install the ssh-singleagent.sh script.

stack/base/Dockerfile

@@ -32,7 +32,7 @@ RUN mkdir -p "${CONDA_DIR}/etc/conda/activate.d" && \
 
 # Configure AiiDA profile.
 COPY config-quick-setup.yaml .
-COPY before-notebook.d/prepare-aiida.sh /usr/local/bin/before-notebook.d/
+COPY before-notebook.d/* /usr/local/bin/before-notebook.d/
 
 # Configure AiiDA.
 ENV SETUP_DEFAULT_AIIDA_PROFILE true
@@ -42,10 +42,16 @@ ENV AIIDA_USER_FIRST_NAME Giuseppe
 ENV AIIDA_USER_LAST_NAME Verdi
 ENV AIIDA_USER_INSTITUTION Khedivial
 
+# Install the load-singlesshagent.sh script as described here:
+# https://aiida.readthedocs.io/projects/aiida-core/en/v2.0.0/howto/ssh.html#starting-the-ssh-agent
+# The startup of this script is configured in the before-notebook.d/setup-ssh.sh file.
+RUN wget --quiet --directory-prefix=/opt/bin/ \
+     "https://aiida.readthedocs.io/projects/aiida-core/en/v${AIIDA_VERSION}/_downloads/4265ec5a42c3a3dba586dd460c0db95e/load-singlesshagent.sh" \
+     && echo $'\n# Load singlesshagent on shell startup.\n\
+if [ -f /opt/bin/load-singlesshagent.sh ]; then\n\
+   . /opt/bin/load-singlesshagent.sh\n\
+fi\n' >> "/home/${NB_USER}/.bashrc"
+
 USER ${NB_USER}
 
 WORKDIR "/home/${NB_USER}"
-
-# Make sure that the known_hosts file is present inside the .ssh folder.
-RUN mkdir -p --mode=0700 /home/${NB_USER}/.ssh && \
-     touch /home/${NB_USER}/.ssh/known_hosts

stack/base/before-notebook.d/setup-ssh.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+# Make sure that the known_hosts file is present inside the .ssh folder.
+mkdir -p --mode=0700 /home/${NB_USER}/.ssh && \
+    touch /home/${NB_USER}/.ssh/known_hosts
+
+
+if [[ ! -f  /home/${NB_USER}/.ssh/id_rsa ]]; then
+  # Generate ssh key that works with `paramiko`
+  # See: https://aiida.readthedocs.io/projects/aiida-core/en/latest/get_started/computers.html#remote-computer-requirements
+  ssh-keygen -f /home/${NB_USER}/.ssh/id_rsa -t rsa -b 4096 -m PEM -N ''
+fi
+
+# Start the ssh-agent.
+eval `ssh-agent`

stack/lab/before-notebook.d/prepare-aiidalab.sh

@@ -11,12 +11,6 @@ if [ -L /home/${NB_USER}/${NB_USER} ]; then
   rm /home/${NB_USER}/${NB_USER}
 fi
 
-if [[ ! -f  /home/${NB_USER}/.ssh/id_rsa ]]; then
-  # Generate ssh key that works with `paramiko`
-  # See: https://aiida.readthedocs.io/projects/aiida-core/en/latest/get_started/computers.html#remote-computer-requirements
-  ssh-keygen -f /home/${NB_USER}/.ssh/id_rsa -t rsa -b 4096 -m PEM -N ''
-fi
-
 # Install the home app.
 if [ ! -e /home/${NB_USER}/apps/home ]; then
     echo "Install home app."