just-mrrc: support file options for the launcher functionality

When just-mr acts as a launcher, for most subcommand options the
"just args" entry in the rc files provides a convenient way to set
them. However, some options take a file as argument; for those it can
be desirable to set them without assuming a fixed file-system layout
and instead refer to logical roots, in particular the work space.
for the ones that refer to files, it is often desirable to have a potential
reference to the work space. Add this functionality.

6 files changed, 153 insertions, 2 deletions

diff --git a/share/man/just-mrrc.5.md b/share/man/just-mrrc.5.md
index 559c4d5f..85c2ce75 100644
--- a/share/man/just-mrrc.5.md
+++ b/share/man/just-mrrc.5.md
@@ -109,8 +109,8 @@ The just-mrrc is given by a JSON object.
 
  - The value for the key *`"authentication"`* is a JSON object specifying
    client-side authentication options for **`just-mr`**.  
-   For subkey *`"ca cert"`* the value is a single location object the path to
-   a TLS CA certificate.  
+   For subkey *`"ca cert"`* the value is a single location object
+   specifying the path to a TLS CA certificate.
    For subkey *`"client cert"`* the value is a single location object specifying
    the path to a TLS client certificate.  
    For subkey *`"client key"`* the value is a single location object specifying
@@ -118,6 +118,14 @@ The just-mrrc is given by a JSON object.
    Each subkey value can be overwritten by its corresponding command-line
    argument.
 
+ - The value for the key *`"just files"`* is a JSON object. The keys correspond
+   to options that some **`just`** subcommands accept and require a file as
+   argument. For each key, the value is a list of location objects. When
+   **`just-mr`** is used as a launcher and the invoked subcommand is known to
+   support this option, this option is set in the **`just`** invocation with
+   the first matching entry, if any. The supported options are *`"config"`*
+   and *`endpoint-configuration`*.
+
  - The value for the key *`"just args"`* is a JSON object. Its keys are
    **`just`** subcommands and its value is a JSON list of strings. For the
    corresponding subcommand, these strings are prefixed to the **`just`**
@@ -153,6 +161,12 @@ An example just-mrrc file could look like the following:
   , "install": ["--remote-execution-property", "OS:Linux"]
   , "rebuild": ["--remote-execution-property", "OS:Linux"]
   }
+, "just files":
+  { "config":
+    [ {"root": "workspace", "path": "etc/config.json"}
+    , {"root": "home", "path": ".just-config"}
+    ]
+  }
 }
 ```
 
diff --git a/src/other_tools/just_mr/cli.hpp b/src/other_tools/just_mr/cli.hpp
index 3d7a8980..b4f6607d 100644
--- a/src/other_tools/just_mr/cli.hpp
+++ b/src/other_tools/just_mr/cli.hpp
@@ -80,6 +80,8 @@ struct MultiRepoJustSubCmdsArguments {
     std::optional<std::string> subcmd_name{std::nullopt};
     std::vector<std::string> additional_just_args{};
     std::unordered_map<std::string, std::vector<std::string>> just_args{};
+    std::optional<std::filesystem::path> config{};
+    std::optional<std::filesystem::path> endpoint_configuration{};
 };
 
 // corresponding to the similarly-named arguments in 'just'
diff --git a/src/other_tools/just_mr/launch.cpp b/src/other_tools/just_mr/launch.cpp
index 4e9403a8..2c771836 100644
--- a/src/other_tools/just_mr/launch.cpp
+++ b/src/other_tools/just_mr/launch.cpp
@@ -48,6 +48,7 @@ auto CallJust(std::optional<std::filesystem::path> const& config_file,
     bool use_launcher{false};
     bool supports_defines{false};
     bool supports_remote{false};
+    bool supports_dispatch{false};
     bool supports_cacert{false};
     bool supports_client_auth{false};
     std::optional<std::filesystem::path> mr_config_path{std::nullopt};
@@ -81,6 +82,7 @@ auto CallJust(std::optional<std::filesystem::path> const& config_file,
         use_launcher = kKnownJustSubcommands.at(*subcommand).launch;
         supports_defines = kKnownJustSubcommands.at(*subcommand).defines;
         supports_remote = kKnownJustSubcommands.at(*subcommand).remote;
+        supports_dispatch = kKnownJustSubcommands.at(*subcommand).dispatch;
         supports_cacert = kKnownJustSubcommands.at(*subcommand).cacert;
         supports_client_auth =
             kKnownJustSubcommands.at(*subcommand).client_auth;
@@ -121,6 +123,10 @@ auto CallJust(std::optional<std::filesystem::path> const& config_file,
         cmd.emplace_back("--plain-log");
     }
     if (supports_defines) {
+        if (just_cmd_args.config) {
+            cmd.emplace_back("-c");
+            cmd.emplace_back(just_cmd_args.config->string());
+        }
         auto overlay_config = Configuration();
         for (auto const& s : common_args.defines) {
             try {
@@ -153,6 +159,10 @@ auto CallJust(std::optional<std::filesystem::path> const& config_file,
         cmd.emplace_back("-r");
         cmd.emplace_back(*common_args.remote_execution_address);
     }
+    if (supports_dispatch and just_cmd_args.endpoint_configuration) {
+        cmd.emplace_back("--endpoint-configuration");
+        cmd.emplace_back(*just_cmd_args.endpoint_configuration);
+    }
     if (supports_remote and common_args.remote_serve_address) {
         cmd.emplace_back("--remote-serve-address");
         cmd.emplace_back(*common_args.remote_serve_address);
diff --git a/src/other_tools/just_mr/rc.cpp b/src/other_tools/just_mr/rc.cpp
index 63e772bf..d8b8067a 100644
--- a/src/other_tools/just_mr/rc.cpp
+++ b/src/other_tools/just_mr/rc.cpp
@@ -103,6 +103,30 @@ namespace {
                           std::filesystem::weakly_canonical(
                               std::filesystem::absolute(root_path / base)));
 }
+
+[[nodiscard]] auto ReadOptionalLocationList(
+    ExpressionPtr const& location_list,
+    std::optional<std::filesystem::path> const& ws_root,
+    std::string const& argument_name) -> std::optional<std::filesystem::path> {
+    if (location_list->IsNone()) {
+        return std::nullopt;
+    }
+    if (not location_list->IsList()) {
+        Logger::Log(LogLevel::Error,
+                    "Argument {} has to be a list, but found {}",
+                    argument_name,
+                    location_list->ToString());
+        std::exit(kExitConfigError);
+    }
+    for (auto const& location : location_list->List()) {
+        auto p = ReadLocation(location, ws_root);
+        if (p and FileSystemManager::IsFile(p->first)) {
+            return p->first;
+        }
+    }
+    return std::nullopt;
+}
+
 }  // namespace
 
 /// \brief Read just-mrrc file and set up various configs. Return the path to
@@ -216,6 +240,26 @@ namespace {
             clargs->common.git_path = git->first;
         }
     }
+    // read the just file-arguments
+    auto just_files = rc_config["just files"];
+    if (just_files.IsNotNull()) {
+        if (not just_files->IsMap()) {
+            Logger::Log(LogLevel::Error,
+                        "Configration-file provided 'just files' has to be a "
+                        "map, but found {}.",
+                        just_files->ToString());
+            std::exit(kExitConfigError);
+        }
+        auto files = Configuration(just_files);
+        clargs->just_cmd.config = ReadOptionalLocationList(
+            files["config"],
+            clargs->common.just_mr_paths->workspace_root,
+            "'config' in 'just files'");
+        clargs->just_cmd.endpoint_configuration = ReadOptionalLocationList(
+            files["endpoint-configuration"],
+            clargs->common.just_mr_paths->workspace_root,
+            "'endpoint-configuration' in 'just files'");
+    }
     // read additional just args; user can append, but does not overwrite
     auto just_args = rc_config["just args"];
     if (just_args.IsNotNull()) {
diff --git a/src/other_tools/just_mr/utils.hpp b/src/other_tools/just_mr/utils.hpp
index 0fc18748..54abd3d5 100644
--- a/src/other_tools/just_mr/utils.hpp
+++ b/src/other_tools/just_mr/utils.hpp
@@ -50,6 +50,7 @@ struct JustSubCmdFlags {
     bool launch;       // supports the local launcher arg
     bool defines;      // supports defines arg
     bool remote;       // supports remote exec args
+    bool dispatch;     // supports dispatching of the remote-execution endpoint
     bool cacert;       // supports CA cert arg
     bool client_auth;  // supports client auth args
 };
@@ -62,6 +63,7 @@ std::map<std::string, JustSubCmdFlags> const kKnownJustSubcommands{
       .launch = false,
       .defines = false,
       .remote = false,
+      .dispatch = false,
       .cacert = false,
       .client_auth = false}},
     {"describe",
@@ -70,6 +72,7 @@ std::map<std::string, JustSubCmdFlags> const kKnownJustSubcommands{
       .launch = false,
       .defines = true,
       .remote = false,
+      .dispatch = false,
       .cacert = false,
       .client_auth = false}},
     {"analyse",
@@ -78,6 +81,7 @@ std::map<std::string, JustSubCmdFlags> const kKnownJustSubcommands{
       .launch = false,
       .defines = true,
       .remote = true,
+      .dispatch = true,
       .cacert = false,
       .client_auth = false}},
     {"build",
@@ -86,6 +90,7 @@ std::map<std::string, JustSubCmdFlags> const kKnownJustSubcommands{
       .launch = true,
       .defines = true,
       .remote = true,
+      .dispatch = true,
       .cacert = true,
       .client_auth = true}},
     {"install",
@@ -94,6 +99,7 @@ std::map<std::string, JustSubCmdFlags> const kKnownJustSubcommands{
       .launch = true,
       .defines = true,
       .remote = true,
+      .dispatch = true,
       .cacert = true,
       .client_auth = true}},
     {"rebuild",
@@ -102,6 +108,7 @@ std::map<std::string, JustSubCmdFlags> const kKnownJustSubcommands{
       .launch = true,
       .defines = true,
       .remote = true,
+      .dispatch = true,
       .cacert = true,
       .client_auth = true}},
     {"install-cas",
@@ -110,6 +117,7 @@ std::map<std::string, JustSubCmdFlags> const kKnownJustSubcommands{
       .launch = false,
       .defines = false,
       .remote = true,
+      .dispatch = false,
       .cacert = true,
       .client_auth = true}},
     {"gc",
@@ -118,6 +126,7 @@ std::map<std::string, JustSubCmdFlags> const kKnownJustSubcommands{
       .launch = false,
       .defines = false,
       .remote = false,
+      .dispatch = false,
       .cacert = false,
       .client_auth = false}}};
 
diff --git a/test/end-to-end/just-mr/defaults.sh b/test/end-to-end/just-mr/defaults.sh
index 57b020f6..12ed5c5f 100644
--- a/test/end-to-end/just-mr/defaults.sh
+++ b/test/end-to-end/just-mr/defaults.sh
@@ -36,6 +36,10 @@ cat > "${SAMPLE_RC}" <<EOF
   , {"root": "system", "path": "${LOG_DIR#/}/rc2.log"}
   ]
 , "local launcher": ["env", "SET_IN_RC=true"]
+, "just files":
+  { "config": [{"root": "workspace", "path": "sample-config.json"}]
+  , "endpoint-configuration": [{"root": "workspace", "path": "endpoint.json"}]
+  }
 }
 EOF
 cat "${SAMPLE_RC}"
@@ -56,6 +60,8 @@ from argparse import ArgumentParser
 
 parser = ArgumentParser()
 parser.add_argument("-C", dest="repository_config")
+parser.add_argument("-c", "--config", dest="build_config")
+parser.add_argument("--endpoint-configuration", dest="endpoint")
 parser.add_argument("--local-build-root", dest="local_build_root")
 parser.add_argument("-L","--local-launcher", dest="local_launcher")
 parser.add_argument("-f", "--log-file", dest="log_file",
@@ -74,6 +80,18 @@ with open(os.path.join(target_dir, "log-limit"), "w") as f:
   f.write(json.dumps(options.log_limit))
 with open(os.path.join(target_dir, "log-file"), "w") as f:
   f.write(json.dumps(options.log_file))
+if options.build_config:
+  with open(os.path.join(target_dir, "config"), "w") as f:
+    f.write(json.dumps(options.build_config))
+else:
+  if os.path.exists(os.path.join(target_dir, "config")):
+    os.unlink(os.path.join(target_dir, "config"))
+if options.endpoint:
+  with open(os.path.join(target_dir, "endpoint"), "w") as f:
+    f.write(json.dumps(options.endpoint))
+else:
+  if os.path.exists(os.path.join(target_dir, "endpoint")):
+    os.unlink(os.path.join(target_dir, "endpoint"))
 with open(os.path.join(target_dir, "launcher"), "w") as f:
   if options.local_launcher:
     f.write(options.local_launcher)
@@ -170,4 +188,58 @@ test $(jq '. == [ {"foo": "override", "baz": "baz"}] ' "${PARSE_DIR}/defines") =
              build -D '{"foo": "override"}' -D '{"x": "y"}' "${PARSE_DIR}" 2>&1
 test $(jq '. == [ {"foo": "bar", "baz": "baz"}, {"foo": "override"}, {"x": "y"}] ' "${PARSE_DIR}/defines") = true
 
+## -c
+
+# honored from rc-file if present
+touch sample-config.json
+"${JUST_MR}" --local-build-root "${LBR}" --just "${PARSE}" \
+             --rc "${SAMPLE_RC}" build "${PARSE_DIR}" 2>&1
+[ -f "${PARSE_DIR}/config" ]
+
+# not honored for non-analysing subcommands
+"${JUST_MR}" --local-build-root "${LBR}" --just "${PARSE}" \
+             --rc "${SAMPLE_RC}" install-cas "${PARSE_DIR}" 2>&1
+[ -f "${PARSE_DIR}/config" ] && exit 1 || :
+
+# not considered an error if not present
+rm -f sample-config.json
+"${JUST_MR}" --local-build-root "${LBR}" --just "${PARSE}" \
+             --rc "${SAMPLE_RC}" build "${PARSE_DIR}" 2>&1
+[ -f "${PARSE_DIR}/config" ] && exit 1 || :
+
+# not considered, if key not present in rc
+cat > tmprc.json <<'EOF'
+{"just files": {"unrelated": 123}}
+EOF
+"${JUST_MR}" --local-build-root "${LBR}" --just "${PARSE}" \
+             --rc tmprc.json build "${PARSE_DIR}" 2>&1
+[ -f "${PARSE_DIR}/config" ] && exit 1 || :
+
+## --endpoint-configuration
+
+# honored from rc-file if present
+touch endpoint.json
+"${JUST_MR}" --local-build-root "${LBR}" --just "${PARSE}" \
+             --rc "${SAMPLE_RC}" build "${PARSE_DIR}" 2>&1
+[ -f "${PARSE_DIR}/endpoint" ]
+
+# not honored for non-endpoint-specific subcommands
+"${JUST_MR}" --local-build-root "${LBR}" --just "${PARSE}" \
+             --rc "${SAMPLE_RC}" install-cas "${PARSE_DIR}" 2>&1
+[ -f "${PARSE_DIR}/endpoint" ] && exit 1 || :
+
+# not considered an error if not present
+rm -f endpoint.json
+"${JUST_MR}" --local-build-root "${LBR}" --just "${PARSE}" \
+             --rc "${SAMPLE_RC}" build "${PARSE_DIR}" 2>&1
+[ -f "${PARSE_DIR}/endpoint" ] && exit 1 || :
+
+# not considered, if key not present in rc
+cat > tmprc.json <<'EOF'
+{"just files": {"unrelated": 123}}
+EOF
+"${JUST_MR}" --local-build-root "${LBR}" --just "${PARSE}" \
+             --rc tmprc.json build "${PARSE_DIR}" 2>&1
+[ -f "${PARSE_DIR}/endpoint" ] && exit 1 || :
+
 echo OK