From 0d0e2b168a557d29b4cdfce8d7168541e932f8c4 Mon Sep 17 00:00:00 2001 From: Joachim Wiberg Date: Wed, 16 Oct 2024 07:28:04 +0200 Subject: [PATCH 1/2] doc: update container notes - Expand on Docker Hello World - Add more pictures to help break up the content a bit Signed-off-by: Joachim Wiberg --- doc/container.md | 16 ++++++++++++++++ doc/img/docker-hello-world.svg | 4 ++++ doc/img/shield-checkmark.svg | 4 ++++ 3 files changed, 24 insertions(+) create mode 100644 doc/img/docker-hello-world.svg create mode 100644 doc/img/shield-checkmark.svg diff --git a/doc/container.md b/doc/container.md index 97fc4181..022ef70e 100644 --- a/doc/container.md +++ b/doc/container.md @@ -105,11 +105,23 @@ application to run. > unlike virtualization, containers reuse the host's CPU and kernel. +Hello World + ### Examples Classic Hello World: admin@example:/> container run docker://hello-world + Starting docker://hello-world :: use Ctrl-p Ctrl-q to detach + Trying to pull docker.io/library/hello-world:latest... + Getting image source signatures + Copying blob c1ec31eb5944 done + Copying config d2c94e258d done + Writing manifest to image destination + Storing signatures + + Hello from Docker! + This message shows that your installation appears to be working correctly. Persistent web server using nginx, sharing the host's network: @@ -223,6 +235,10 @@ archive, which helps greatly with container upgrades (see below): Upgrading a Container Image --------------------------- +Hello World + +The applications in your container are an active part of the system as a +whole, so make it a routine to keep your container images up-to-date! > **Note:** the default writable layer is lost when upgrading the image. > Use named volumes for content that you want to persist across upgrades. diff --git a/doc/img/docker-hello-world.svg b/doc/img/docker-hello-world.svg new file mode 100644 index 00000000..d35d9a13 --- /dev/null +++ b/doc/img/docker-hello-world.svg @@ -0,0 +1,4 @@ + + + +
> Hello
World
 \ No newline at end of file diff --git a/doc/img/shield-checkmark.svg b/doc/img/shield-checkmark.svg new file mode 100644 index 00000000..01064567 --- /dev/null +++ b/doc/img/shield-checkmark.svg @@ -0,0 +1,4 @@ + + + + \ No newline at end of file From 99e0a2ee1c7ccc03c6c334646532fcb3bc18e941 Mon Sep 17 00:00:00 2001 From: Joachim Wiberg Date: Wed, 16 Oct 2024 07:31:50 +0200 Subject: [PATCH 2/2] confd: refactor hostnamefmt() This refactor, and massive code simplification, is a follow-up to the double free discovery in 3b4d2b3. Beacuse a hostname in Linux can never be more than 64 chars, we can safely use a stack buffer instead of calloc(), reducing complexity and simplifying the code further with the use of strlcat(). Signed-off-by: Joachim Wiberg --- src/confd/src/core.h | 3 +- src/confd/src/ietf-system.c | 80 ++++++++------------------------ src/confd/src/infix-containers.c | 8 ++-- 3 files changed, 25 insertions(+), 66 deletions(-) diff --git a/src/confd/src/core.h b/src/confd/src/core.h index ae25a7d3..4c2de35c 100644 --- a/src/confd/src/core.h +++ b/src/confd/src/core.h @@ -172,7 +172,8 @@ int ietf_interfaces_init(struct confd *confd); int ietf_syslog_init(struct confd *confd); /* ietf-system.c */ -int ietf_system_init(struct confd *confd); +int ietf_system_init (struct confd *confd); +int hostnamefmt (struct confd *confd, const char *fmt, char *buf, size_t len); /* infix-containers.c */ #ifdef CONTAINERS diff --git a/src/confd/src/ietf-system.c b/src/confd/src/ietf-system.c index c95b8b7b..ffe833a3 100644 --- a/src/confd/src/ietf-system.c +++ b/src/confd/src/ietf-system.c @@ -1595,23 +1595,6 @@ static char *get_mac(struct confd *confd, char *mac, size_t len) return mac; } -#define REPLACE_SPECIFIER(replacement) \ - do { \ - size_t repl_len = strlen(replacement); \ - char *ptr; \ - \ - hostlen += repl_len; \ - ptr = realloc(hostname, hostlen + 1); \ - if (!ptr) { \ - free(hostname); \ - free(*fmt); \ - return -1; \ - } \ - hostname = ptr; \ - strlcat(hostname, replacement, hostlen + 1); \ - j += repl_len; \ - } while (0) - /* * Decode hostname format specifiers (non-standard, Infix specifc) * @@ -1622,82 +1605,62 @@ static char *get_mac(struct confd *confd, char *mac, size_t len) * * NOTE: to be forward compatible, any unknown % combination will be silently consumed. * E.g., "example-%z" will become "example-" - * - * XXX: PLEASE REFACTOR THIS INTO A PYTHON HELPER FOR FUTURE EXTENSIONS, OR BUGS! */ -int hostnamefmt(struct confd *confd, char **fmt) +int hostnamefmt(struct confd *confd, const char *fmt, char *buf, size_t len) { - size_t hostlen, fmt_len; - char *hostname; char mac[10]; - size_t i, j; - - if (!fmt || !*fmt || !strchr(*fmt, '%')) - return 0; + size_t i; - hostlen = fmt_len = strlen(*fmt); - hostname = calloc(hostlen + 1, sizeof(char)); - if (!hostname) + if (!fmt || !*fmt) return -1; - for (i = 0, j = 0; i < fmt_len; i++) { - if ((*fmt)[i] == '%') { - switch ((*fmt)[++i]) { + memset(buf, 0, len); + + for (i = 0; i < strlen(fmt); i++) { + if (fmt[i] == '%') { + switch (fmt[++i]) { case 'i': - REPLACE_SPECIFIER(id); + strlcat(buf, id, len); break; case 'h': - REPLACE_SPECIFIER(nm); + strlcat(buf, nm, len); break; case 'm': - REPLACE_SPECIFIER(get_mac(confd, mac, sizeof(mac))); + strlcat(buf, get_mac(confd, mac, sizeof(mac)), len); break; case '%': - if (j < hostlen) { - hostname[j++] = '%'; - hostname[j] = 0; - } + strlcat(buf, "%", len); break; default: break; /* Unknown, skip */ } } else { - if (j < hostlen) { - hostname[j++] = (*fmt)[i]; - hostname[j] = 0; - } + char ch[2] = { fmt[i], 0 }; + strlcat(buf, ch, len); } } - free(*fmt); - *fmt = hostname; - return 0; } -#undef REPLACE_SPECIFIER - static int change_hostname(sr_session_ctx_t *session, uint32_t sub_id, const char *module, const char *xpath, sr_event_t event, unsigned request_id, void *priv) { struct confd *confd = (struct confd *)priv; const char *hostip = "127.0.1.1"; - char *hostnm, buf[256]; + char hostnm[65], buf[256]; + const char *fmt; FILE *nfp, *fp; int err, fd; if (event != SR_EV_DONE) return SR_ERR_OK; - hostnm = srx_get_str(session, "%s", xpath); - if (!hostnm) { + fmt = srx_get_str(session, "%s", xpath); + if (!fmt) { fallback: - hostnm = strdup(nm); - if (!hostnm) { - err = SR_ERR_NO_MEMORY; - goto err; - } - } else if (hostnamefmt(confd, &hostnm)) + strlcpy(hostnm, nm, sizeof(hostnm)); + } else if (hostnamefmt(confd, fmt, hostnm, sizeof(hostnm))) goto fallback; err = sethostname(hostnm, strlen(hostnm)); @@ -1754,9 +1717,6 @@ static int change_hostname(sr_session_ctx_t *session, uint32_t sub_id, const cha systemf("avahi-set-host-name %s", hostnm); systemf("initctl -nbq touch netbrowse"); err: - if (hostnm) - free(hostnm); - if (err) { ERROR("Failed activating changes."); return err; diff --git a/src/confd/src/infix-containers.c b/src/confd/src/infix-containers.c index 27be820f..492e7220 100644 --- a/src/confd/src/infix-containers.c +++ b/src/confd/src/infix-containers.c @@ -21,8 +21,6 @@ #define ACTIVE_QUEUE "/var/lib/containers/active" #define LOGGER "logger -t container -p local1.notice" -int hostnamefmt(struct confd *confd, char **fmt); - static int add(const char *name, struct lyd_node *cif) { @@ -50,12 +48,12 @@ static int add(const char *name, struct lyd_node *cif) fprintf(fp, " --dns-search %s", lyd_get_value(node)); if ((string = lydx_get_cattr(cif, "hostname"))) { - char *fmt = (char *)string; + char buf[65]; - if (hostnamefmt(&confd, &fmt)) + if (hostnamefmt(&confd, string, buf, sizeof(buf))) ERRNO("%s: failed setting custom hostname", name); else - fprintf(fp, " --hostname %s", fmt); + fprintf(fp, " --hostname %s", buf); } if (lydx_is_enabled(cif, "read-only"))