[PATCH 2/4] apt: Generate Isar reprepro database

[Alexander Smirnov <asmirnov@ilbers.de>]

Generate reprepro database for Isar apt repository.

Signed-off-by: Alexander Smirnov <asmirnov@ilbers.de>
---
 meta-isar/conf/layer.conf        |  3 +++
 meta-isar/conf/local.conf.sample |  4 ++++
 meta/classes/image.bbclass       | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/meta-isar/conf/layer.conf b/meta-isar/conf/layer.conf
index 0950a34..cd42f06 100644
--- a/meta-isar/conf/layer.conf
+++ b/meta-isar/conf/layer.conf
@@ -22,3 +22,6 @@ DEBDISTRONAME = "isar"
 
 # Path to the Isar apt repository
 DEPLOY_DIR_APT ?= "${DEPLOY_DIR}/apt"
+
+# Path to the Isar databases used by `reprepro`
+DEPLOY_DIR_DB ?= "${DEPLOY_DIR}/db"
diff --git a/meta-isar/conf/local.conf.sample b/meta-isar/conf/local.conf.sample
index a456b1b..660958f 100644
--- a/meta-isar/conf/local.conf.sample
+++ b/meta-isar/conf/local.conf.sample
@@ -158,3 +158,7 @@ IMAGE_INSTALL = "hello example-raw"
 #
 # Default parallel jobs for bitbake:
 BB_NUMBER_THREADS = "4"
+
+#
+# Number of attempts to try to get reprepro lock for access to apt cache
+REPREPRO_LOCK_ATTEMPTS = "16"
diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index 57705a7..47f53a3 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -10,6 +10,31 @@ IMAGE_ROOTFS   = "${WORKDIR}/rootfs"
 
 inherit ${IMAGE_TYPE}
 
+call_reprepro() {
+    for i in $(seq 1 ${REPREPRO_LOCK_ATTEMPTS}); do
+        #  According to `sh` manual page, shell exit statuses fall between
+        # 0-255. The EEXIST error code is (-17), so casting to usigned 8-bit
+        # integer results value (239).
+        eexist=$(python -c 'import errno; print(256-errno.EEXIST)')
+        retval="0"
+        reprepro $* || retval="$?"
+
+        # If reprepro has failed to get database lock, it returns EEXIST code.
+        # In this case we continue trying to get lock until max amount of
+        # attempts is reached.
+        if [ $retval -eq $eexist ]; then
+            bbwarn "Failed to get reprepro lock, trying again..."
+            sleep 5
+        else
+            break
+        fi
+    done
+
+    if [ $retval -ne 0 ]; then
+        bbfatal "reprepro failed"
+    fi
+}
+
 CACHE_CONF_DIR = "${DEPLOY_DIR_APT}/${DISTRO}/conf"
 do_cache_config[dirs] = "${CACHE_CONF_DIR}"
 do_cache_config[stamp-extra-info] = "${DISTRO}"
@@ -21,6 +46,15 @@ do_cache_config() {
         sed -e "s#{DISTRO_NAME}#"${DEBDISTRONAME}"#g" \
             ${FILESDIR}/distributions.in > ${CACHE_CONF_DIR}/distributions
     fi
+
+    path_cache="${DEPLOY_DIR_APT}/${DISTRO}"
+    path_databases="${DEPLOY_DIR_DB}/${DISTRO}"
+
+    if [ ! -d "${path_databases}" ]; then
+        call_reprepro -b ${path_cache} \
+                      --dbdir ${path_databases} \
+                      export ${DEBDISTRONAME}
+    fi
 }
 
 addtask cache_config before do_fetch
-- 
2.1.4